Technologies for Ocean Exploration · E.Chandrasekar, M. Murugesh, Radhakrishnan and C. Jothi. viii...

Technologies for Ocean Exploration

Sponsored by

Ministry of Earth Sciences, Govt. of India

Jointly organised by

Ocean Society of India

&

National Institute of Ocean Technology

OSICON-11

OSICON 11 is the second national conference of Ocean Society of India (OSI)

to be held during 13-15, July 2011 at National Institute of Ocean Technology

(NIOT). OSI always believes in building partnerships and this time we had

the privilege of having NIOT as our partner. OSICON 11 is thus jointly

conducted by OSI and NIOT. The focal theme chosen for this conference is

“Technologies for Ocean Exploration” and hence NIOT is the right choice for

conducting this conference, since it is the premier institute of ocean technology

in our country. You might remember that we conducted our previous

conference OSICON 09 at Visakhapatnam in March 2009 with partnership of

Andhra University. Since the inception of Ocean Society of India (OSI) in

2006, we have been receiving tremendous support and cooperation in

furthering the R&D work in marine sciences, engineering and technology.

Over these years, OSI built strong bonding with several pioneering institutions

like NIO, NPOL(and sister labs of DRDO), NIOT, SAC, INCOIS, NRSC, IOM,

Indian Navy, IIT-Kharagpur, IIT-Madras, IIT-Delhi, IISc, Cochin University

of Science & Technology, Goa University, Jadavpur University, Anna

University and Andhra University. OSI has its life members spread across

length and breadth of our country from all of the institutions mentioned

above. One of the greatest strengths of OSI is its young research scholars and

students who are willing to take part in our activities. We look forward to

build more partnerships in future also.

A broad range of topics of current interest is covered for OSICON 11. The

various themes on which papers will be presented are Autonomous

Underwater Vehicles, Remotely Operated Vehicles, Ocean Engineering, Safety

& Reliability, Sonar Technologies, Ocean Observation Systems, Ocean Remote

Sensing & Applications, Ocean State Forecasting (Ocean Modeling), Ocean

Dynamics, Coastal Processes & Coastal Zone Management, Marine

Ecosystems, Bio-geochemistry of Oceans and Atmosphere & Oceans. A total

of one hundred and seventeen (117) papers have finally been selected for the

conference after peer reviewing all the abstracts received. We have arranged

the review of abstracts by inviting the technical subject experts to a common

venue and completed the review process. We are extremely grateful to all

the technical committee members and other subject experts who assisted for

the review of abstracts. Especially the services rendered by Dr K Ravindran,

Dr MR Santha Devi, Dr KV Sanil Kumar, Dr GVM Gupta, Dr KK Balachandran,

and Shri OR Nanda Gopan are very much appreciated. Dr K Rajith and Shri

PSV Jagadeesh have contributed quite significantly in organising abstracts

and for bringing out the compendium of abstracts of OSICON 11. As the

time available for oral presentations is limited (even with parallel sessions)

iii

we encouraged all the paper presenters to prepare the posters also, in addition

to oral presentations, for display at the conference venue. It gives an

opportunity to delegates in extending their discussions even after completion

of their oral presentations. Apart from these papers there are six invited

talks for this conference by eminent experts in key areas of marine science,

engineering and systems.

Dr Shailesh Nayak, Secretary, Ministry of Earth Sciences has given lot of

encouragement and guidance in organising this conference. Both the

organisations, OSI and NIOT, are grateful to him for all the help rendered in

organising OSICON 11. Deliberations of this conference will certainly help

understanding of our oceans better and lead to state-of-the-art ocean

technologies for future. We thank all the delegates of this conference for their

continued interest and enthusiasm for our OSICON series.

Dr CVK Prasada Rao

Chairman, Technical Committee

OSICON-11

iv

National Advisory Committee

Dr. Shailesh Nayak Secretary, MoES Chairman

Dr. M. A. Atmanand Director, NIOT, Chennai Co-Chairman

Dr. Ajit P. Tyagi Director General, IMD Member

Dr. S. R. Shetye Director, NIO, Goa Member

Dr. Rasik Raveendra Director, NCAOR, Goa Member

Dr. V. Bhujanga Rao Director, NSTL, Visakhapatnam Member

Shri. S. Anantha Narayanan Director, NPOL, Kochi Member

Dr. R. R. Navalgund Director, SAC, Ahmedabad Member

Dr. S. K. Dube Emeritus Professor, IIT, Delhi Member

Dr. D. Sen Professor, IIT, Kharagpur Member

Dr. V. Sundar Professor, IIT, Madras Member

Dr. Satheesh C. Shenoi Director, INCOIS, Hyderabad Member

Dr. P. V. Joseph President, OSI Convener

Dr. C.V.K. Prasada Rao Scientist, NPOL, Kochi Chairman

Dr. K. Ravindran Former Director, CIFT, Kochi Co-Chairman

Shri. V. Chander Former Director, NPOL, Kochi Advisor

Dr. G. Latha Scientist, NIOT, Chennai Member

Dr. M. Sudhakar Scientist & Advisor, MoES Member

Dr. M.R. Santha Devi Former Scientist, NPOL, Kochi Member

Dr. A.D. Rao Professor, IIT, New Delhi Member

Dr. M.R. Rameshkumar Scientist, NIO, Goa Member

Dr. K.V. Sanil Kumar Scientist, NPOL, Kochi Member

Shri. O.R. Nanda Gopan Scientist, NPOL, Kochi Member

Dr. K. Rajith Scientist, NPOL, Kochi Member

Shri. P.S.V. Jagadeesh Scientist, NPOL, Kochi Member

Dr. B.K. Jena Scientist, NIOT, Chennai Chairman

Dr. M. Harikrishnan Scientist, NPOL, Kochi Co-Chairman

Dr. G. Latha Scientist, NIOT, Chennai Member

Dr. S. Ramesh Scientist, NIOT, Chennai Member

Shri. A.N. Subramaniam Scientist, NIOT, Chennai Member

Dr. P. Nammalwar Rajan Project Leader, IOM Anna Univ. Member

Technical Committee

Local Organising Committee

v

vi Ocean Society of India

INVITED TALKS

1 Strides in Deep Sea Technologies – Indian Experience 02Dr. M. A. Atmanand

2 Indians Estuaries: Need for Concerted Action 03

Dr. Satish R. Shetye

3. Coastal Processes and Management with particular reference to 04

SW coast of India

Dr. N.P. Kurian

4. Role of Ocean Atmospheric Process over the Tropical Indian Ocean 05

on the Monsoon Activity over the Indian Sub Continent:A Study Using Remote Sensing DataDr. M.R. Ramesh Kumar

5. The influence of Oceans on Indian Summer Monsoon 06

Dr. P. V. Joseph

6. Coastal Surveillance and Harbour Protection 07

Dr. J. Narayana Das

Contents

OSICON Proceedings 13-15 July 2011

Ocean Society of India vii

THEME-1 AUTONOMOUS UNDERWATER VEHICLES

AUV-1 Effect of Armour Configuration on Strength Characteristics of 10

Underwater Tow Cables

Sameer Abdul Azeez, Anshath Hussain N., K. Sudarsan

AUV-2 Underwater Terrain Mapping with a 5-DOF AUV. 10

Shikha, S. K. Das, D. Pal, S. Nandy, S. N. Shome, Soma Banerjee

AUV-3 Identification and tracking of objects by Autonomous Underwater 12

Vehicle for Coastal Surveillance

Anubhav Sahoo, Siddhant Agarwal and Dhaval Prajapati

AUV-4 Hydrodynamic Design of an Underwater Towed System 13

Roni Francis and K.Sudarsan

AUV-5 Dynamic Model for Maneuverability and Controllability Studies of AUVs. 14

Debabrata Sen

AUV-6 Role of Depressors In Two Part Towed System - A Simulation Study 15

Minu Paulose, K Ajithkumar, K Sudarsan

AUV-7 Naukaa – An Automated System to Measure Water Quality Parameters 15

T.Suresh, Madhubala Talaulikar, S.G. Prabhu Matondkar, Aneesh Lotlikar

THEME-2 REMOTELY OPERATED VEHICLES

ROV-1 Performance of Electrical Power System of Remotely Operable 18

Submersible (Rosub 6000) in KG Basin & Central Indian Ocean Basin

Deep Sea Trials.

Subramanian AN, Harikrishnan G, Muthukumaran D, Elangovan S,

Vadivelan A, Ramadass. G.A, Atmanand MA

ROV-2 Characteristics of Intermediate water mixing phenomena in 18

Indian Ocean recorded from the Dissolved Oxygen Optode of

ROSUB 6000 – ROV

S.Ramesh and G.A.Ramadass

ROV-3 Dual mode operation of ROV-500: Design & Control Aspects 20

Sambhunath Nandy, Sankar Nath Shome, Dibyendu Pal, Chandan

Har and Pratik Saha

ROV-4 Deep water sampling tool design and integration with Work Class 21

ROV – ROSUB 6000

J.Manecius Selvakumar, S.Ramesh, D.Sathia Narayanan, S.B.Pranesh,

E.Chandrasekar, M. Murugesh, Radhakrishnan and C. Jothi

viii Ocean Society of India

THEME-3 OCEAN ENGINEERING, SAFETY AND RELIABILITY

OESR-1 Development of a ship weather-routing algorithm and its application 24

to the north Indian Ocean region

Chinmaya P. Padhy and Debabrata Sen

OESR-2 A Study of Reliability and Safety on Dynamic Positioning System of 25

ORV Sagar Nidhi

D.Rajasekhar, N.Ravi and Anantha Krishna Rao

OESR-3 Development and testing of model suction piles in the NIOT test pond 26

Vijaya Ravichandran, R.Ramesh, J.Manecius Selvakumar, Muthukrishna Babu,

G.A.Ramadass and M.V. Ramanamoorthy

OESR-4 A New Concept and Design of a Low Cost Wave Energy Converter 28

Pradip Deb Roy and Debabrata Sen

THEME-4 SONAR TECHNOLOGIES

ST-1 Finite element analysis of vibration isolation module with nylon rope 30

strength member

Beena.B.R, M. Sabu Sebastian, Manojkumar and S.Jithu

ST-2 Reverberation Measurements of Acoustic Tank 31

A.Malarkodi and Dhanalakshmi

ST-3 Application of Wavelets for Analysing Ship Noise from shallow water 31

ambient Noise Measurements

M. Ashokan, P. Edwards Durai and K.Nithyanandam

ST-4 Acoustic Intensity fluctuations induced by environmental parameters 32

in coastal waters

Sanjana M C, G Latha and A.Thirunavukkarasu

ST-5 Measured broadband reverberation characteristics in Deep ocean 33

Baiju M Nair, M Padmanabham and M P Ajaikumar

ST-6 MATLAB code for tow characteristics of an underwater towed system 34

Ambily Vijayan, K Ajith Kumar and K Sudarsan

THEME-5 OCEAN OBSERVATION SYSTEMS

OOS-1 Analysis on Under Water Seismic Event on June 12, 2010 recorded by 36

Indigenous Tsunami Early Warning System

M .Arul Muthiah, Tamil Mugilan, R.Venkatesan

OOS-2 Analysis of Antenna placement on Data Buoy Systems for 37

INMARSAT Satellite Communication

K.Ramesh, M. Arulmuthiah, P. Murugesh, R.Venkatesan

OOS-3 An ARGO Based Study on the Water Mass Characteristics of the 38

Bay of Bengal and the Arabian Sea

Sourav Sil, Sudip Jana and Arun Chakraborty


Ocean Society of India ix

OOS-4 Coastal wave measurement using HF Radar 39

Manu P. John, Rajnish Antala, Sisir K. Patra and B. K. Jena

OOS-5 Inter-comparison of wave measurement by Accelerometer and 40

GPS buoy in shallow water off Cuddalore, east coast of India.

Sisir K Patra, B K Jena and K M Siva Kholundu

THEME-6 OCEAN REMOTE SENSING & APPLICATIONS

ORSA-1 Validation of Satellite Derived Precipitation Data 42

Abdulla C.P. and M.R. Ramesh Kumar

ORSA-2 Sea level and eddy kinetic energy variability in the Bay of Bengal from altimetry 43

K.Palanik Kumar and P.P. Saheed

ORSA-3 Potential Fishing Zone advisories- Are they beneficial to the coastal 44

fisherfolk?- Kerala experience

V.N.Pillai and Preetha.G.Nair

ORSA-4 Sea Surface Temperature estimation for condenser coolant 44

discharges from a power plant using satellite data

C. Anandan, R. Kaviyarasan, M. Sankar Ram, P.Sasidhar and V. Balasubramaniyan

ORSA-5 Upwelling in the southeastern Arabian Sea as evidenced by Ekman mass 45

transport using wind observations from OCEANSAT–II Scatterometer

Smitha, A., Ajith Joseph, K., Chiranjivi Jayaram and A. N. Balchand

ORSA-6 Sources of Errors in the Measurements of Underwater Profiling Radiometer 46

Noah S, T Suresh, Madhubala T, Bhushan P, Prabhu M and Aneesh L

ORSA-7 Change Detection Studies of Rameswaram Island, India Using Remote 47

Sensing and GIS

R.Gowthaman, G.S. Dwarakish, V. Sanil Kumar and P. Vinayaraj

THEME-7 OCEAN STATE FORECASTING (OCEAN MODELING)

OSF-1 Modeling of coastal inundation due to storm surges: 50

A case study for Andhra coast

P L N Murty, A D Rao and S K Dube

OSF-2 Numerical simulation and mechanism of mini-cold pool off the 50

southern tip of India during summer monsoon season.

A D Rao and D K Mahapatra

OSF-3 Numerical Hindcasting of storm waves during LAILA cyclone using 51

reanalyzed wind fields.

Arun Kumar, S.V.V., K.V.S.R. Prasad, K.V.K.R.K. Patnaik, Ch. Venkata Ramu,

P.S.N. Acharyulu, D. Mani kumari and A.P.V. Apparao

OSF-4 Numerical simulation of cyclone movement using high resolution Regional 52

Ocean model: A case study for the cyclone MALA (24-29 April, 2006)

Bishnu Kumar and Arun Chakraborty

x Ocean Society of India

OSF-5 Indian Ocean Simulation Results from NEMO Global Ocean Model 53

Imran M. Momin, Ashis K. Mitra, D. K. Mahapatra and L. Harenduprakash

OSF-6 Time lagged Multiple Linear Regression Model Using Key Indices 54

of SST Fluctuations for Smaller Domains of Oceans

Anbarasan, M. R., S. Sundararajan, B.K. Jena, B. Vijay Bhaskar and S. Chandrasekaran

OSF-7 Wave forecast from wind parameters using Genetic Algorithm: 55

A case study for the Bay of Bengal

A D Rao, Mourani Sinha and Sujit Basu

OSF-8 Simulations of tropical cyclone generated storm surges over North 56

Indian Ocean using advanced coastal hydrodynamic model

Maria Antonita. T, Remya P.G and Rajkumar

OSF-9 Ocean Surface Forcing from AGCM:Medium Range Systematic Errors 57

for Monsoons

D. K. Mahapatra, A. K. Mitra, E. N. Rajagopal, Imran Ali and L. Harendu Prakash

OSF-10 Assimilation of significant wave height from EnviSAT in coastal wave 58

model using optimum interpolation at variable wave height ranges

Suchandra A. Bhowmick, Raj Kumar and Sutapa Chaudhuri

OSF-11 Development of an automated Coupled Atmosphere-Ocean Modeling 58

System and Its Application for the Kalpakkam Region

SubbaReddy Bonthu, Kaushik Sasmal, Hari.V.Warrior and Prageesh, A. G.

OSF-12 Validation of Eddy Viscosity Model in the Laboratory 59

Subhendu Maity and Hari V. Warrior

OSF-13 Indian Ocean Response to Windforcing Using LCS Model 60

Surenda, M.

OSF-14 Doubling of Tsunami wave while at the sea shore: an analytical study 61

Ramkrishna Datta

OSF-15 An implementation of Optimal Interpolation for wave height analysis 62

over Indian waters

Sasikala, N. and S.A. Sannasiraj

OSF-16 Wave Hindcasting using Artificial Neural Network with varying input 63

Parameter

J. Vimala and G. Latha

OSF-17 Altimetry and drifter data assimilation in an Indian Ocean circulation model 64

Manisha Santoki, K. N. Joshipura, Smitha Ratheesh, Rashmi Sharma and Sujit Basu

OSF-18 Tsunami Inundation Modelling and Mapping along Marina Beach, 65

Chennai Using Cartosat-1 Data

Kankara, R. S., S. Chenthamil Selvan, Tune Usha and V. Ram Mohan


Ocean Society of India xi

OSF-19 Sensitivity Study of Near-shore Wave induced Setup during an 66

Extreme Event in the Bay of Bengal

Prasad K. Bhaskaran and A.G. Prajeesh

THEME-8 OCEAN DYNAMICS

OD-1 Barrier Layer Formation In The Bay of Bengal as Observed by 68

Omni Buoys During Northeast Monsoon

Simi Mathew, G. Latha and R. Venkatesan

OD-2 Spatial and Temporal Variation of Heat Content in the Upper 69

70m layer of the Arabian Sea

Gopika. N and Sajeev. R

OD-3 Influence of Indian Ocean Dipole (IOD) on Northeast Monsoon 70

K.N.Navaneeth and M.R.Ramesh Kumar

OD-4 Influence of IOD events on sea surface height variability and 71

circulation characteristics along the south - west coast of India

Phiros Shah and R Sajeev

OD-5 Water Mass Characteristics of the Andaman Sea 71

Sudip Jana and Arun Chakraborty

OD-6 Seasonal cycles of heat budget components during the contrasting 72

years of 2004 and 2007

Muraleedharan, P.M., Keerthi, M.G., Nisha, P.G.

OD-7 Sea breeze induced wind sea generation and growth in the central 74

west coast of India during pre-monsoon season

V.M. Aboobacker, P. Vethamony, M. Seemanth

OD-8 The role of Thermal inversions on Hydro-physical processes along 75

the coastal waters off Visakhapatnam, East coast of India

Sridevi, T., Maneesha, K. and V.V.S.S. Sarma

OD-9 Variability of near-surface temperature fields on Intra-seasonal to 76

inter-annual time scales in the south eastern Arabian Sea (SEAS)

Nisha Kurian, V.V.Gopalakrishna, R.R.Rao, S.Amritash, Lix John and C.Revichandran

OD-10 Influence of Mesoscale Eddy on Vertical Mixing and Spreading of 77

Water Mass in the Arabian Sea

Maheswaran, P.A. Dominic Ricky Fernandez and J. Swain

OD-11 Characteristics of Bay of Bengal Water mass in the South Eastern 77

Arabian Sea during 2001-2002

Nageswara Rao G., K Anil Kumar, PSV Jagadeesh and P Anand

OD-12 Air-sea interactions and upper ocean thermal structure variations 78

during different epochs of MALA Cyclone over Bay of Bengal

Naresh Krishna Vissa, A.N.V. Satyanarayana, and B. Prasad Kumar

xii Ocean Society of India

OD-13 Implication of Empirical Orthogonal Function Analysis to Objectively 79

Analyzed Ocean Temperature Data of Bay of Bengal

Tarumay Ghoshal, Sudip Jana and Arun Chakraborty

OD-14 Dynamics of intraseasonal thermocline variability in the Tropical Indian 80

Ocean during 2004

Bhasha M. Mankad, Rashmi Sharma, Sujit Basu and P. K. .Pal

OD-15 Effect of Sea ice melting on the mixed layer depth variation in the 80

Indian Ocean Sector of the Southern Ocean

Pranab Deb, Mihir K. Dash, P. C. Pandey

THEME-9 ATMOSPHERE & OCEANS – CLIMATE CHANGE

AOCC-1 Response of Aerosol Optical Depth (AOD) to the general cycle of 82

global climate in the western and eastern Indian Ocean.

Shalin Saleem, KV Sanilkumar, CA Babu and CVK Prasada Rao

AOCC-2 Effects of Atmospheric Interferences on Coastal HF Radar Measurements 82

Rajnish Antala, Manu P John and B. K. Jena

AOCC-3 On the Relative Roles of Onset Vortex and Mini Warm Pool over the Arabian 83

Sea on the Monsoon Onset over Kerala

Ramesh Kumar, M.R. and Syam Sankar

AOCC-4 Climate Change and Its Impacts on Marine Fisheries 84

Nammalwar P., S.Satheesh and R. Ramesh

AOCC-5 Impact of Rossby waves on the variation of Indian summer monsoon 85

Dhrubajyoti Samanta, M K Dash and P C Pandey

THEME-10 (A) MARINE ECOSYSTEMS

ME-1 Impact of Coastal Processes and Geomorphology on turtle nesting along 88

Orissa coast, East coast of India

P.K. Mohanty, S.K.Patra, B. Seth, U.K Pradhan, B. Behera, S. Barik,

P.K. Kar, S. Bramha, P. Mishra and U.S.Panda

ME-2 Bacterial Abundance in Godavari Estuary: Influence of River Discharge 89

on Bacterial Metabolism

Manjary, D.T., V. R. Prasad, L. Gawade and V.V.S.S. Sarma

ME-3 Studies on effects of photosynthetically active radiation in chlorophyll a 90

during post monsoon season off Cochin waters

Minu P, S.S Shaju., G. Archana, P. Muhamed Ashraf, B. Meenakumari

ME-4 Vertical and Horizontal Distribution of Chlorophyll ‘a’ and Phytoplankton 90

from Pondicherry-Nagapattinam Waters, Southeast Coast of India.

Sampathkumar P., K. Kamalakannan, C. Thenmozhi, R. Sankar and T. Balasubramanian

ME-5 Seasonality in the Distribution and Abundance of Macrobenthic 91

Fauna in the Cochin Estuary and Adjacent Coastal Shelf.

Rehitha, T.V., N. V. Madhu, R. Reshmi, G. Vijay John, C. Revichandran


Ocean Society of India xiii

ME-6 Plankton metabolic activity and its role on dissolved organic carbon 92

dynamics in a tropical lagoon, Chilika: India

K.Vishnu Vardhan, R.S.Robin, Pradipta R Muduli, B.Charan Kumar, A.Lova Raju,

D.Ganguly, S.Patra, G.Nageswara Rao, A.V.Raman and B.R.Subramanian

ME-7 Influence of Allochthonous Input on Trophic Switch Over and CO2efflux 93

In a Shallow Tropical Lagoon Chilika Lagoon, India

Robin, R.S., Pradipta R. Muduli, K.VishnuVardhan, B. Charan Kumar,

Shoji D. Thottathil, U.S.Panda, Sivaji Patra, T. Balasubramanian,

A.V. Raman and B.R. Subramanian

ME-8 Estimating Chlorophyll-a Concentration Using First - Derivative 94

Spectra in Coastal Waters of Bay of Bengal Along East Coast of India

Gopala Reddy, K., Srikanth Ayyala Somayajula, B. Srinivasa Rao

ME-9 Application of a Ecosystem Model to Study the Dynamics of Nutrients in 95

Chilika Lagoon

Uma Sankar Panda, Sivaji Patra, R.S. Robin, K.VishnuVardhan,

Pradipta R. Muduli, D. Ganguly and B. R. Subramanian

ME-10 Distribution of Benthic Polychaete Species and Relation with 95

Biogeochemical Factors in East Coast of India

Naidu, S.A. and V.V.S.S. Sarma

ME-11 Meso-Scale Atmospheric Events Promote Phytoplankton Blooms in 96

The Coastal Bay of Bengal

Maneesha, K. and V.V.S.S. Sarma

ME-12 Environmental factors controlled by phytoplankton biomass and 97

production rate in the estuarine waters off Cochin

Dayala V.T and Sujatha C.H

ME-13 Diurnal variation of plankton in Godavari estuary 98

Bharathi, M.D.,V. Venkataramana and V.V.S.S. Sarma

ME-14 Influence of River Discharge on Phytoplankton Community Structure 99

in the Coastal Bay of Bengal

Bandhopadhyay D., T. Acharyya and V.V.S.S. Sarma

ME-15 Development of Water Quality Index for Coastal Region of Visakhapatnam 100

using Statistical Techniques

Sangeeta Pati, M. K. Dash, C. K. Mukherjee and B. Dash

ME-16 River Discharge: A Critical Factor Controlling Phytoplankton Biomass 101

and Community Composition in Monsoon Driven Godavari Estuary

Acharyya T., D.Bandyopadhyay and V.V.S.S. Sarma

ME-17 Coastal and off shore Phytoplankton Pigment Profile of North Bay of 102

Bengal with reference to TSM and Turbidity

Sanghamitra Palleyi, R. N. Kar and C. R. Panda

xiv Ocean Society of India

ME-18 Spatial Distribution of Zooplankton along Orissa Coast in Dry Season 103

Suchismita Srichandan, N. C. Rout and C. R. Panda

ME-19 Oscillating environmental responses of the eastern Arabian Sea 104

Vijay John Gerson, Madhu. N. V, Jyothibabu. R, Balachandran. K. K,

Maheswari Nair, Revichandran C.

THEME-10 (B) BIO-GEO CHEMISTRY OF OCEANS

BCO-1 Variability of DMS and its Related Compounds in East Coast of India 106

Viswanadham, R., V.D. Rao and V.V.S.S. Sarma

BCO-2 Temporal Variability of Dissolved Inorganic Carbon Budget from a 106

Tropical Shallow Lagoon, Chilika, India

Prdipta.R.Mudulia, K.Vishnu Vardhan, R.S. Robin, B. Charan Kumar, A.Chandra

Mouli, U.S.Panda, Sivaji Patra, G.Nageswarara Rao, A.V.Raman, B.R. Subramanian

BCO-3 Source and Fate of Terrestrial Organic Carbon in Sediments along the 107

East Coast of India

Krishna, M.S.R., V.V.S.S. Sarma, Lata G, SA Naidu, Ch V Subbaiah,

P Praveen Kumar

BCO-4 Seasonal Trends in the Aerosol Components over the Cochin Estuarine System 108

Jose Mathew, Gayathree Devi and Sujatha, C.H.

BCO-5 Seasonal variation in physico - chemical parameters in relation to organo 109

chlorine pesticides in the Cochin Estuary

Salas.P.M. and Sujatha, C.H.

BCO-6 Spatial and Vertical transmission Pattern of Pigments and their 110

Assimilation with Nutrients in the Southern Ocean (SO) water mass

Sujatha C.H., Akhil P.S., Deepulal P.M., Sini Pavithran, Sharon B. Noronha, N. Anil Kumar.

BCO-7 The distribution of REE’s along South coast of India 111

Deepulal, P.M, Gireesh Kumar. T.R. and Sujatha. C.H.

BCO-8 Distribution of Labile Organic Carbon in the Godavari Estuary and 111

Adjacent Ground Waters

B.S.S. Kumar, V.R.Prasad and V.V.S.S. Sarma

BCO-9 Variability of Trace Gases in the Godavari Estuary: Influence of 112

Ground Water Exchange

Durga Rao, G., V.D. Rao and V.V.S.S. Sarma

BCO-10 Organic carbon modification in the dam reservoir to support 113

heterotrophic carbon demand in the Godavari estuary

Prasad, V. R. , B.S.K. Kumar and V.V.S.S. Sarma

BCO-11 Stable Isotopes of Carbon and Nitrogen in Suspended Matter and 114

Sediments from the Godavari Estuary

Subbaiah, C.V., S. A. Naidu and V.V.S.S. Sarma


Ocean Society of India xv

BCO-12 Sources of Particulate Organic Carbon and Nitrogen in the Gautami 114

Godavary Estuary

Lata Gawade and V.V.S.S.Sarma

BCO-13 Seasonal Variation of Water Quality Parameters at Puri, East Coast 115

of India-a Pollution Study

Baliarsingh, S.K., M.K Khadanga, and K. C Sahu

BCO-14 Dredging Impacts on the Coastal Water Quality of Dhamra, Orissa 116

Seoul Sangita, D.R., Satapathy, R.N. Kar and C.R.Panda

BCO-15 Suspended matter induced nutrient biogeochemistry in a river plume 117

dominated tropical shallow lagoon Chilka, India.

Sivaji Patra, R.S. Robin, Prdipta.R.Muduli, K.Vishnu Vardhan, U.S.Panda

and B.R. Subramanian

THEME-11 COASTAL PROCESSES & COASTAL ZONE MANAGEMENT

CPCZM-1 Hydrodynamic and dispersion modeling of coastal tropical lagoon: 120

a case study in Chilika lagoon

Uma Sankar Panda, V. Ranga Rao, B. R. Subramanian, R. N. Samal and

M. M. Mohanty

CPCZM-2 Flux measurements at the Cochin Harbour Inlet using Acoustic 120

Doppler Profiler

Revichandran, C., K.R. Muraleedharan, V.K. Jineesh, Vijay John Gerson,

Shivaprasad Amaravayal and M. Rafeeq

CPCZM-3 Impact of mining on the stability of a placer mining beach 121

Rajith, K., N.P. Kurian and V.R. Shamji

CPCZM-4 Acoustic Doppler Velocimeter Measurements of Surf Zone 122

Currents Along Visakhapatnam-Gangavaram Coast.

Ranga Rao, V., S.V.V., Arun kumar, K.V.S.R.Prasad, Ch Venkata Ramu,

K.V.K.R.K Patnaik and M. Manikandan

CPCZM-5 Intra-Annual Varibility of Wave Characteristics at a Nearshore 123

Location in West Coast of India

Jossia Joseph, K. and B. K. Jena

CPCZM-6 Assessment of Shoreline Changes of Chennai, Tamil Nadu Using 124

GIS (3d Vectorisation) and Digital Image Processing Techniques

Kankara, R. S., B. Rajan, S. Chenthamil Selvan, V. Ram Mohan

CPCZM-7 Management of Shoreline Morphological Changes Due to Breakwater 125

Construction along a Stable Coast

Noujas, V., K.O.Badarees, N.R.Ajeesh, L.Sheela Nair, T.S.S.Hameed and

K.V.Thomas

xvi Ocean Society of India

CPCZM-8 Investigation of Geomorphic processes on Mulky - Pavanje 126

Rivermouth, West Coast India

Gumageri Nagaraj and Dwarakish G S

CPCZM-9 Enhanced stratification during neap tide of Godavari Estuary 127

Sridevi, B. V.V.S.S. Sarma and T.V. Ramana Murty

CPCZM-10 Role of Bottom Friction in a Tidal Estuary Under Combined 128

Action of Waves and Currents and its Validation

Chitra Arora and Prasad K. Bhaskaran

CPCZM-11 Prospects for Developing a Minor Port Facility at Betul, Goa 129

Thomas Mathai, Satish Kumar, K.N. Rajarama, P. Praveen Kumar

and M. Suresh Chandran.

LIST OF OSI LIFE MEMBERS 131

OSI MEMBERSHIP FORM

INVITED TALKS

2 Ocean Society of India

IT-1

Strides in Deep Sea Technologies – Indian Experience

Dr. M. A. Atmanand

Director, National Institute of Ocean Technology, Chennai

Abstract

Development in deep sea technologies in India started very recently. While the navalapplications called for deep sea systems up to a depth of 200 metres or less, the advent ofdeep sea oil availability in the deep sea has resulted in explorations of deep oceansinternationally. India has very few institutes working in deep sea technologies and NIOTis the pioneer in this area. Work started way back in end 90’s with the development ofunderwater crawler mounted sand mining system as part of Poly Metallic Noduleprogramme of the erstwhile Department of Ocean Development, now Ministry of EarthSciences. The experience gained while developing the system initially with foreigncollaboration, resulted in building up of a strong deep sea technology group in NIOT.This crawler based mining system was later modified by the internal team at NIOT and arefurbished system was designed and tested again for sand mining from on board OceanResearch Vessel, Sagar Kanya. Later the crawler mounted system was re-designed fornodule collection, crushing and pumping to ship. This was tested at a depth of 500mfrom on board Ocean Research Vessel Sagar Nidhi. Work on system development to minemanganese nodules from a depth of 6000m is currently progressing.

Another deep sea vehicle, Remotely Operable Vehicle (ROV) was designed and developedas part of another programme, tested and qualified up to a depth of 5189 metres at theCentral Indian Ocean Basin (CIOB). Even though this was with Russian collaboration,the complete electrical, instrumentation and control system was developed by engineersat NIOT independently.

In order to measure the soil properties in the Central Indian Ocean Basin (CIOB), it isessential to have an instrument, which will measure in-situ bearing strength and shearstrength. A soil tester was developed and tested at a depth of 5200 metres in CIOB by theNIOT team.

Many underwater systems and components were indigenized as spin off from the variousprojects indicated above. Some of them are the underwater fibre optic connector,underwater transformer, underwater thruster etc.

The design features of these and the test results will be covered in detail in the presentation.


Ocean Society of India 3

IT-2

Indians Estuaries: Need for Concerted Action

Dr. Satish R. Shetye

National Institute of Oceanography, Dona Paula, Goa

Abstract

Well over a hundred estuaries, large enough and important enough to be taken note of,border the Indian coastline. These estuaries have special features that are derived fromoccurrence of the wet Indian Summer Monsoon (June-September) and hence have beendubbed monsoonal estuaries. High runoff during the wet season and a 8-month long dryseason with little runoff lead to striking temporal changes in salinity and velocity fieldsin these estuaries. Only a handful of these estuaries have been studied to describe theirspecial features.

A number of habitats have adapted to the temporal variability observed in the estuaries.Because the estuaries have been a favoured location for human settlement, anthropogenicimpacts on the estuaries have risen sharply. In some cases the impacts are severe becausemany large cities have grown on banks of the estuaries. However, as yet there has notbeen a concerted nationwide effort to ensure health of these systems. Such an effort willrequire gathering of large multidisciplinary data, their analyses, formulation of policyaimed at preservation of health of the estuaries, and implementation of well thought outaction plans.

Keeping in view the large number of estuaries that border the Indian coastline, the efforttowards data gathering and analyses would be large. Hence, it would be advisable toseek participation of colleges and universities in the effort towards data collection andanalysis. The participation need not be restricted to educational institutions already havingoceanography as a discipline. New institutions can be roped by imparting short-termtraining to faculty and students in departments interested in getting involved inenvironmental issues. In fact, the opportunity of such an involvement offers the prospectof enlarging popular awareness of the problem. This is necessary for legislation for policyformulation to keep the estuaries healthy. In short, concerted action involving governmentagencies, education and research institutions, and organizations like the Ocean Societyof India is need of the hour.


IT-3

Coastal Processes and Management with particularreference to SW coast of India

Dr. N. P. Kurian

Centre for Earth Science Studies, Thiruvananthapuram

Abstract

The coasts are dynamic systems, undergoing adjustments of form and processes at differenttime and space scales in response to oceanographic and geomorphologic factors. Coastal processescan be defined as the set of mechanisms that operate along a coastline, bringing about variouscombinations of erosion and deposition that in turn influence the geomorphic form and evolutionof the coast. The geomorphic form and evolution of coasts are largely controlled by six majorfactors: waves, tides, offshore topography, bedrock geology, sediment supply and sea-levelchanges. The coastal zone is constantly under the action of tide, waves, wind and currents andthe energy due to these external forces is constantly acting in the coastal zone. Because of this theland water interface along the coastline is always in a highly dynamic state and nature workstowards maintaining an equilibrium condition. Dissipation of energy (due to tide, wind, wavesand current) is often provided by the beaches, mudflats, marshes and mangroves. Sedimenttransport is one of the important processes in the coastal zone induced by the hydrodynamicprocesses. The alongshore and cross-shore transport of sediment as a result of the hydrodynamicprocesses determine the sediment budget and erosion/accretion status of the coast.

In addition to the long and short-term natural processes, there is human interference by buildingstructures for commercial, defence and coastal protection applications and more recentlyrecreational and tourism activities. Coastal development is now causing a significant conflictwith natural coastal processes. Knowledge of coastal processes in the area concerned is requiredto develop strategies for sustainable coastal zone management.

The Integrated Coastal Zone Management Plan (ICZMP) is considered to be a tool to managethe problems of the coastal zone and devise a plan for sustainable development. It takes careof sustainable use, development and protection of coastal and marine areas and its resourcesby ensuring that all sectors and all levels of government are involved in the decision makingprocess. In spite of the availability of a large amount of coastal data from numerous researchand technical organisations, significant information gaps still exist. An integrated coastal zonemanagement plan needs to define a long-term sustainable plan, even though that may changewith time. There will always be uncertainty associated with considering the long-term, bothin terms of extrapolating information and making predictions regarding coastal infrastructuredevelopments, risks, future legislative requirements, opportunities and constraints.Consequently, a primary function of the CZM should be to demonstrate that coastal zonemanagement policies proposed today, i.e. in the short-term, are not detrimental to achievementof a sustainable management plan. The paper presents an overview of the coastal processes ofthe southwest coast of India and case studies on integrated coastal zone management plan.



IT-4

Role OoOcean Atmospheric Process over the Tropical IndianOcean on the Monsoon Activity over the Indian Sub

Continent: A Study Using Remote Sensing Data

Dr. M.R. Ramesh Kumar

Scientist, Physical Oceanography Division, National Institute of Oceanography, Dona Paula, Goa

Abstract

The southwest monsoon or the summer monsoon which gives about 80% of the mean annualrainfall for the various meteorological subcontinent is one of outstanding meteorologicalphenomena of the Indian Meteorology [ Ananthakrishnan et al., 1983]. In a typical monsoonseason, the monsoon sets in over the Kerala coast by 1st June and covers the entire Indiansubcontinent by 15th July. The quantum of monsoon rainfall also varies from year to year. Themonsoon rainfall is not continuous within the life cycle of monsoon; there are several spells ofactive, weak and break in monsoon conditions. The summer monsoon months of June toSeptember contribute 21%, 33%, 28% and 18% of the seasonal rainfall respectively. Thus it canbe seen that the mid monsoon months July and August contribute about 61% of the meanseasonal rainfall. Hence, prolonged breaks can in these mid monsoon months can create deficitmonsoon or drought like conditions as in the case of 2002, which incidentally had the longestbreak spell of 34 days according to Ramesh Kumar and Uma [2004].

The air-sea interaction processes over the Indian Ocean are studied using the sea surfacetemperature from the NOAA/NASA Oceans pathfinder best SST product. The columnar watervapour, wind speed, sensible heat flux, latent heat flux from the recently released high resolutionsatellite data called Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite (HOAPS)are all examined for contrasting monsoon phases, namely, the active and break in monsoonconditions. The Outgoing Longwave Radiation (OLR) and the rainfall from the GlobalPrecipitation Climatology Programme (GPCP) product were also analysed for the above twocontrasting phases. We have used the criteria of Ramesh Kumar and Uma (2004) for identifyingthe active and break in monsoon conditions for the study period (1988-2010). An analysis ofthe various air-sea interaction processes over the Indian Ocean for the active (1988, 1989, 1994,1995) and break in monsoon conditions (1993, 1995, 1999, 2000, 2002, 2009) composite showedthat the evaporation rates almost doubled from break to active monsoon conditions over thenorthern Bay of Bengal. The evaporation rates and integrated columnar water over the northernArabian Sea were also found to play a vital role during the active monsoon conditions. Thewinds increased by about 3 m/s higher over these regions during the active monsoon conditions.It was also found that the integrated columnar water vapour above 700 hPa played a majorrole in the northern Arabian Sea during the active monsoon conditions. The convectivemaximum (OLR minimum) in Bay of Bengal has also helped in the moisture transport intothe subcontinent during active monsoon conditions. In the Eastern Equatorial Indian Ocean(EEIO), the convection was more (less) during the break (active) monsoon conditions.


IT-5

The Influence of Oceans on Indian Summer Monsoon

Dr. P.V. JosephProfessor Emeritus, Department of Atmospheric Science,

Cochin University of Science and Technology, Fine Arts Avenue, Cochin, India

Abstract

Ocean surface temperature maximum has a great control on the location of the InterTropical Convergence Zone (ITCZ) in the tropics and the deep cumulonimbus clouds andrain associated with it. Southwest monsoon sets in over India after ITCZ moves acrossthe equator to the northern hemisphere over the Indian ocean. The large scale (spatial)sea surface temperature (SST) anomalies on either side of the equator in Indian and Pacificoceans are found related to the timing of this monsoon onset.

Severe droughts in the Indian monsoon during June to September cause warm SSTanomalies over tropical Indian ocean and cold SST anomalies over the west Pacific ocean.These anomalies in the ocean persist till the following monsoon making it give higherrainfall. Thus we do not get in India long runs of drought years as in sub-Saharan Africa,thanks to the ocean.

Recent studies have shown that the Active – Break cycle of the monsoon is the result ofocean – atmosphere interaction on the time scales of 30 - 60 days. We first knew of thelarge variation in north Bay of Bengal SST on the 30-60 day time scale after NIOTestablished moored buoy stations there in 1997-1998. We are hopeful that the coupledocean – atmosphere modelling using high speed computing systems that has just begunin India will help us achieve skillful medium range forecast (two week ahead) of monsoonrainfall of India

In the global warming scenario the SST of equatorial Indian Ocean has warmed muchmore than the other oceans during the period 1950 to date. This rapid warming of theequatorial Indian Ocean has caused the weakening of the monsoon wind flow throughIndia which has been related to the observed decreasing trend in the frequency of monsoondepressions.



IT-6

Coastal Surveillance and Harbour Protection

Dr. J Narayana Das

Chief Controller R&D (NS&M), DRDO, New Delhi

Abstract

Two thirds of the world population lives within 100 km of the coastline. India has 7000km of coastline. Major mode of trade depends on maritime operations. We have nearly200 major and minor ports. Several major national assets such as power plants, shipyards,chemical industries, heavy industries etc are located along the coastline. Apart fromthat, we have large assets offshore which are also vulnerable targets. Through the searoute enemy can come dangerously close, covertly without any advance warning. Thethreats are operative all the time, in war and peace. There could be state operators aswell as non state players. 24/7 surveillance through multiple sensors, mechanisms tocollate data, derive information, effective communication, decision support systems thatfacilitates quick response to engage and neutralize the threat, all have to be in place.

The threat could be in the form of small boats, fishing crafts, unmanned surface vehicles,AUVs, Divers, swimmers, drifting mines, remote controlled vehicles and the like. Theoperating zones are generally ports and harbours, where there will always be sizeablecongestion of regular traffic of ocean going vessels, including the large number of fishingboats and crafts. While the vessels above 30 m are mandated to have the AIS systems thatenable Vessel tracking and Monitoring, the smaller vessels have no such identification,today. Detection, isolation and tracking the activities of suspects of this category needsspecial efforts and technologies.

Surface threats: Use of Fishing boats, like 26/11 Mumbai Attack, is a major cause ofconcern. Their detection and isolation from the registered vessels and tracking themdown using surveillance radars alone is not practical. There is a need to institute specialAIS systems on all registered vessels. Such systems should also provide special servicesto the crew, such as identifying fishing zone, special help in case of emergency etc so as tomotivate them to install and maintain the new system. Looking at the data and the needto further scalability it is necessary to have satellite links of communication, in place.Radar systems capable of resolving 20 m class vessels at a reasonable range of say 10 km,over the sea clutter and all weather conditions itself poses technology challenges. Thermalimagers and high-resolution electro optic systems are also necessary in order to classify,augment and enable decision support systems.


Subsurface Threats: Subsurface threats like AUVs and divers are more difficult to bedetected and tracked. In the congested coastal zone, detecting small TCS targets usingSONARs alone becomes possible only at short ranges. A diver approaching at 0.5m/sec,detected at say 500m, gives just 1000 seconds to resolve, decide and implement action forneutralization. In the case of small AUVs the scenario is still adverse. Mobile detectionsystems mounted on AUVs that can deploy RF links for communication when an alert isperceived can be used for off coast patrolling. Apprehending suicide attacks, it may beeven necessary to neutralize the threat much before the intruder can reach the targetinstallation.

In a broad sense coastal surveillance and harbour protection systems are very complexinvolving multidisciplinary technologies. Speed in detection analysis, decision andimplementation are keys to success.



ABSTRACTS

THEME-1 AUTONOMOUS UNDERWATER VEHICLES


AUV-1

Effect of Armour Configuration on Strength Characteristicsof Underwater Tow Cables

Sameer Abdul Azeez, Anshath Hussain N., K. Sudarsan

Naval Physical and Oceanographic Laboratory, Thrikkakara, Kochi

Underwater cables used in towed applications like Anti-Submarine Warfare (ASW) oroceanographic research are distinguished by the presence of load-carrying structuralarmour. The armour acts as the ‘mechanical lines’ of the cable in addition to the electricallines or electric cum fibre optic lines, resulting in electromechanical and electro-opto-mechanical cables respectively. Depending on the type of the armour material, the towcables are classified as ‘Heavy Tow Cable’ and ‘Light Tow Cable’. Using metals, generallysteel, in the design of the armour lends weight to the cable and renders it negativelybuoyant. On the other hand, when materials like aramid are used in armouring, the cablebecomes lightweight or neutrally buoyant. The design of the tow cable is a highlyspecialized area. To a large extent, the failure of the cable during harsh ocean towingconditions is due to the inadequate design of the armour. In a vast majority of the cases,a double-layer contra-helical design is used for the armour, to achieve torque-balance inthe cable. This is done by employing opposite lay angle directions in the inner and outerlayers of the cable. This paper studies the effects of different types of armour configurationson the strength characteristics of a steel-armoured electro-opto-mechanical cable. Threedifferent double-layer configurations are considered for this heavy tow cable subjectedto tensile, torsional and bending loads. Finite element techniques are applied to estimatethe effective stresses, changes in diameter, axial strains and reaction torques in the cable.It is found that the cable has a better performance in terms of strength characteristicswhen the wire diameter of the inner armour layer is higher than that in the outer layer.

AUV-2

Underwater Terrain Mapping with a 5-DOF AUV

Shikha, S. K. Das, D. Pal, S. Nandy, S. N. Shome, Soma Banerjee

Central Mechanical Engineering Research Institute, Durgapur, CSIR, India

The aim of this paper remains to introduce the extensive application of a state-of-the-artAutonomous Underwater Vehicle (AUV-150) capable of operating up to a depth of 150meters, without any human intervention. The AUV-150 has been developed to performseabed mapping and collect oceanographic data like salinity, temperature and conductivity



at various depths. In this regard, various functional aspects of the system shall also bediscussed in this paper.

The AUV-150 is a cylindrical-shaped carrier with streamlined fairing to reducehydrodynamic drag. It is embedded with active propulsion, navigation, and controlsystems. Equipped with a camera, CTD and side scan sonar as payload sensors the AUV-150 is perfectly designed for performing underwater terrain mapping as well asoceanographic survey activities.

The present paper discusses the navigation and guidance issues on the one hand as wellas underwater terrain mapping done at Idukki Lake located at Cochin in Kerala, India onthe other. Various mission trials have been conducted at the lake with AUV-150 from25.09.10 to 09.10.10. Typical lawnmower, square and straight course missions have beenconducted towards effective lake-floor mapping and bathymetry. Testing was carried outin a 500 x 500 meter square area with the launching point close to 9.8020 N/ 76.8940 E GPScoordinates. The average altimetry observed was close to 15 meters ranging from as lowas 8 meters towards the banks to as high as 26 meters towards the middle of the lake.

The navigational autonomy has been achieved on large scale through the effectivecoordinated operation of controller, navigational sensors, and actuators, altogethergoverned by a control software architecture running on a dual core x86 processor with aclock frequency of 2.0 GHz. The positional information from INS has been improvisedthrough integration of GPS as well as DVL data. Since, the GPS is non-functional whileunderwater, therefore positional data inconsistency from INS up to a specified limit, hasbeen corrected for using dead reckoning technique with DVL data.

A typical deep survey Side-Scan-Sonar (SSS) with 4000 meters standard depth ratingsand optimized resolution, data rates and power requirements, matching best with theAUV-150 hardware design specifications, is used as a major payload sensor for mappingunderwater terrain. Adopting the latest CHIRP signal processing technique, the SSS,operated at 325 KHz and 657 KHz of frequencies, provides digital data with improvedrange resolution and sonar images with fine clarity.

Apart from the directly obtained images, the digital data obtained from the lake trails ispost-processed using MATLAB to sort out the positional coordinates and the heightinformations and the sorted data is further manipulated through Non-Uniform RationalB-Spline (NURBS) modeling using OpenGL, with a view towards rendering a3 dimensional plot of the seabed-contour.


AUV-3

Identification and tracking of objects by AutonomousUnderwater Vehicle for Coastal Surveillance

Anubhav Sahoo, Siddhant Agarwal and Dhaval Prajapati

Department of Ocean Engineering and Naval Architecture, Indian Institute of Technology, Kharagpur

Nurali Nizar Virani and Siddartha Khastgir

Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur

The aim of this paper is to provide a schema for coastal surveillance for AUVs. Theproposed work aims to develop the current knowledge base of underwater surveillanceand observation techniques using an Autonomous Underwater Vehicle. In this paper, thetask of coastal surveillance encompasses three major areas namely Object detection, Objectidentification and Object tracking. Object identification involves approximatelydetermining the velocity, the heading of the foreign body and to make a log along withphotos taken periodically for offline analysis. In this mode, the AUV is static and canonly use the pan-tilt setup to track the object as long as it is in the visible range. If theobject of interest is to be tracked as per the mission guidelines, the task of pursuit involvespath planning based on dynamically changing destination while avoiding obstacles in a3D space. These tasks are achieved through image processing from a visual input systemin real-time and by additional help from proximity sensors. Special considerations ineach proposed technique is made for the limited vision range within the marineenvironment. The obstacle avoidance module has been achieved by the usage of a novelalgorithm and it is validated by various test cases.

The two stage implementation of mission planner, global and local planning serve todivide the tasks and follow the modular approach to accomplish a mission. Though, theframework proposed is independent of the type of AUV being used, simulations and testcases have been studied for a differential drive based thrusters for surge motion and acentral thruster for heave motion. The paper is concluded by validating the proposedframework for coastal surveillance and discussing the results obtained from varioussimulations.

Keywords: Static tracking, Path Planning, Obstacle Avoidance, Vision-guided navigation,Coastal Surveillance.



AUV-4

Hydrodynamic Design of an Underwater Towed System

Roni Francis and K.Sudarsan

Naval Physical and Oceanographic Laboratory, Kochi

Cable towed bodies are used in military, paramilitary and civilian applications such asanti-submarine warfare, oceanography and geophysics. A typical towed system comprisesof a hydrodynamically designed underwater body housing a payload, towed by a surfaceship using an electro-mechanical or electro-opto-mechanical cable. Design of the towedsystem is a complex process involving consideration of various parameters such as thesize and weight of payload, cable forces, spatial geometry of the cable, depth and stabilityof the towed body in horizontal as well as in vertical plane while in tow.

In the present paper the design of a cable towed system is described. The designrequirements include specifications of the cable, size and weight of the pay load, speedand operational depth. The design objective is to evolve the parameters of the towedsystem such as the cable scope and the dimensional configuration of the towed bodysuch that the towed body is positioned at the required depth of tow for the given speedof the tow ship. Hydrodynamic stability is also addressed in both pitch and yaw planes.

The shape and dimensions of the towed body are determined based on the size of thepayload to be housed. The required depth of operation can be achieved by increasing thecable payout or by increasing the area of fin. Hence the optimum values of cable pay outand area of fin are initially determined. The cable geometry and cable tension aredetermined with the help of Podes tables.

The lift to be generated by the fins of the towed body are then determined based on therequired cable tension. The geometry of the fin section is selected based on the NACAprofiles. The parameters of the fins such as dimensions, aspect ratio, sweep back angleare then determined.

The stabilizer fins (aft fins) of the towed body are designed based on the requirements ofstability in yaw and pitch. The mathematical expressions for the moment coefficients inpitch and yaw are evolved. The parameters of the stabilizer fins such as the aspect ratio,slope of lift curve and area of the fins are varied until desired stability parameters areachieved in both pitch and yaw planes.


AUV-5

Dynamic Model for Maneuverability andControllability Studies of AUVs

Debabrata Sen

Dept. of Ocean Engineering & Naval Architecture, IIT Kharagpour 721302, India

For the past couple of decades, AUVs of different shapes, sizes, endurance and missionrequirements are being developed for exploration of the ocean and its resources all overthe world. Several AUVs are also being developed in India. In order to study theirmaneuverability and controllability aspects and to design suitable control algorithms,appropriate dynamic models are required along with estimation of hydrodynamic andcontrol coefficients. In general, there are three classes of submerged vehicles operating inthree different speed and time regimes: (i) torpedoes operating at high speeds for timedurations measured in minutes, (ii) submarines operating at mid-speed range for timedurations measured in days and months, and (iii) AUVs operating at low-speed rangefor durations measured in hours. Although all three are submerged vehicles, due to thedifferences in the speed and time ranges as well as mission requirements, theirhydrodynamic behaviour and consequently maneuverability and controllabilitycharacteristics are quite different. The dynamic models for the first two types of genericvehicles are quite well established: historically these two types of vehicles were underdevelopment for over half a century and the technology is very mature. AUVs on theother hand are relatively new type of underwater vehicles, and because of the low-speedoperational requirements, these vehicles have considerably different maneuverabilitycharacteristics. In this paper, we discuss development of suitable mathematical modelfor AUVs and more importantly identify and discuss the associated hydrodynamiccoefficients and methods of their estimation. Discussion is also made on appropriatenessand usefulness of CFD studies for determining these coefficients, and it is shown that atpresent, CFD can make estimation of only a very few of the required coefficients, whichis insufficient to study maneuverability and controllability aspects of these vehicles.



AUV-6

Role of Depressors in Two Part Towed System -A Simulation Study

Minu Paulose*, K Ajithkumar, K Sudarsan

Naval Physical and Oceanographic Laboratory, Kochi, Kerala, India*National Institute of Technology, Calicut, Kerala, India

An investigation on depth keeping mechanism of a towed system using hydrodynamicand weighted depressor is carried out at different towing speeds and cable payouts. Thetowed body have to maintain certain constant depth for the effective performance of thesensors, considering ocean parameters. Drag force and tension experienced during towingoperation is severely affected by the length of the cable paid out, it is essential to minimisethe length of primary tow cable. Hence, the simulation is done at different primary cablepayout to predict the optimised cable length that can be used for the system. The simulationwas carried out using the numerical tool for three configurations, viz single part towedsystem, two part towed system with weighted depressor and hydrodynamic depressor.It is observed from the simulation results that a hydrodynamic depressor which is 1/16th

weight of weighted depressor gives same depth when towed with same cable payout andtow speed. The advantage of using a hydrodynamic depressor compared to weighteddepressor is brought out in this paper.

Keywords:- Depressor, Two part towed system, towed body, flexible module, simulation

AUV-7

Naukaa – An Automated System to MeasureWater Quality Parameters

T.Suresh, Madhubala Talaulikar, S.G. Prabhu Matondkar, Aneesh Lotlikar*

National Institute of Oceanography, Goa

*Indian National Centre for Ocean Information and Services, Hyderabad, India

Measurements of water quality parameters of rivers and coastal are essential formonitoring its health. The periodic measurements will allow determining the variabilityof critical parameters and thus relate their effects on ecology and marine environment,pollution, sediment transport, productivity and related aspects. Naukaa is an in-housedeveloped small portable battery operated automated system that can be operated in amoving canoe to map the water parameters in short span of time. The system comprisesof microcontroller, water sampling unit, GPS, data transfer unit and sensors. The


microcontroller controls the water-sampling unit, acquires the data from the sensors andGPS and transfers the data to the server and laptop using wireless devices. The sensorsthat measure parameters include are depth, temperature, salinity, chlorophyll, blue-green-algae, dissolved oxygen and turbidity. Additional sensors can be interfaced with ease.For its operation, Naukaa is placed in the canoe, and as the canoe moves in the river, thewater is periodically pumped via a small hosepipe to the unit and after measurementsthe water is drained off. The data acquired is stored on a flash disk. The data can bedownloaded to a laptop or sent to a server on land via wireless devices. Operating Naukaain the River Mandovi and Zuari provided variations in parameters at high spatialresolution. This low cost system provides an opportunity to study the temporal and spatialvariations of water parameters from the coastal waters, rivers, dams and canals with easeand less time.



ABSTRACTS

THEME-2 REMOTELY OPERATED VEHICLES


ROV-1

Performance of Electrical Power System ofRemotely Operable Submersible (Rosub 6000) in

KG Basin & Central Indian Ocean Basin Deep Sea Trials

Subramanian AN, Harikrishnan G, Muthukumaran D,

Elangovan S,Vadivelan A, Ramadass. G.A, Atmanand M.A

National Institute of Ocean Technology, Chennai, India

Remotely operated vehicles are the main tools in exploring and exploiting subsearesources. Gas hydrates and poly metallic nodules are major promising resources whichare available at different deep sea depths. Exploration and exploitation of the above saidresources is a nascent technology. A work class Remotely Operable Submersible (ROSUB-6000) has been designed and developed at NIOT in joint collaboration with EDBOE, Russia.This paper describes the electrical power system and its performance of ROSUB 6000 inthe deep sea trials, KG basin and Central Indian Ocean basin. The paper presents theoperating performance of various components of electrical power system of ROSUB-6000enriched with problems faced during deep sea trials in above said two sites at criticaldepths. Major electrical components dealt were high frequency high voltage converters,special purpose subsea high frequency transformers, subsea power converters, BLDCmotor thrusters and pumps.

ROV-2

Characteristics of Intermediate water mixing phenomena inIndian Ocean recorded from the Dissolved Oxygen

Optode of ROSUB 6000 - ROV

S.Ramesh and G.A.Ramadass

National Institute of Ocean Technology, Chennai

Dissolved oxygen profiles in ocean basin are a useful tracer for tracking the movement ofwater-types and water masses, especially those in the deep and bottom waters. Dissolvedoxygen normally finds in saturation degree in the euphotic layer, and its concentrationdecreases toward the main thermocline where a minimum concentration layer appears.In marine environments Dissolved Oxygen (DO) availability studies will insight tounderstand the resultant process of the interplay of physicochemical (atmosphericexchange and mixing) and biological (photosynthetic production and respiration)activities. South Equatorial Current (SEC) is the permanent circulation feature in the



Central Indian Ocean Basin (CIOB) which influences the mixing phenomena ofintermediate waters. The SEC, in general, extends between 10oS and 16oS and exhibitsseasonal (north-south) shifts with its northern boundary moving up to 4oS during southernwinter. Vertical flow of water through conveyor belt circulation mechanism takes richcontents of oxygen to deeper waters. This dictates the terms of availability for theorganism’s presence in Deep Ocean. Present study deals with the observed temperature,salinity, sound velocity and dissolved oxygen profiles collected during the deep waterqualification sea trial of ROSUB 6000 (Remotely Operated Submersible - ROV). ROSUB6000 is a deep water work class ROV developed at NIOT with design capability to workup to 6000 m water depth. Different phases of sea trial were performed during 2009-2010and carried out more than 15 dives covering Bay of Bengal, Arabian Sea, Equatorial regionand Central Indian Ocean Basin. ROSUB 6000 - ROV is connected with scientific payloadssuch as Dissolved Oxygen sensor, sound velocity profiler and conductivity sensor forreal time data collection apart from other intended activities with cameras, multi-beamsonar and robotic arms. Data collected from ARGO floats are also compared andconsidered for interpretation to establish the intermediate water circulation phenomena.Dissolved Oxygen profiles indicate second maxima of DO level at a depth of 400 m apartfrom surface payer. At 400 m depth highest concentration of was recorded (200 µM) at12.5oS and 75oE which is gradually reducing to less than 50 µM at Arabian Sea (12oN and75oE). Even though the profiles were available up to the maximum of 5289 m from ROSUB6000 CIOB sea trial, for the present study data collected upto 1600 m to 2000 m depth atequatorial region and western part of Arabian Sea and Bay of Bengal are compared toarrive up on mixing characteristics of dissolved oxygen in Indian Ocean. Higherconcentration of dissolved oxygen in Central Indian Ocean Basin and the dilution of DOconcentration due to very low DO content of Arabian Sea water are clearly established bythe reduction in concentration. These mixing phenomena may be happening due to theinfluence of Sverdrup’s Indian Ocean Central Water which is termed as Sub-AntarcticMode Water (SAMW). This paper deals with the DO, water temperature, salinity andsound velocity vertical profile characteristics recorded from ROSUB 6000 system andARGO floats and establishes the mixing phenomena of intermediate waters to make secondmaxima of dissolved oxygen in Central Indian Ocean Basin.


ROV-3

Dual mode operation of ROV-500: Design & Control Aspects

Sambhunath Nandy, Sankar Nath Shome, Dibyendu Pal,

Chandan Har, Pratik Saha

Central Mechanical Engineering Research Institute, Durgapur, CSIR-CMERI, India

This paper highlights the detail design and control of a Remotely Operated Vehicle (ROV)up-to a depth of 500m with a maximum forward velocity of 4 knots and payload capacityof 30 kgf. The developed ROV can be manoeuvred under water from an on-ship surfacecontrol station autonomously or through joysticks depending on the operational need.

The present ROV is a tethered, open frame mobile robotic system suitable for envisagedshallow water applications with appropriate payload & navigational sensors and multi-thruster based motion controllers. Five numbers of DC brushless thrusters (of 93 kgfcapacity each) are mounted in three orthogonal directions to manoeuvre the ROV in water.Two thrusters are mounted horizontally in forward direction to control forward motion(surge & sway) and heading (yaw); two thrusters are mounted in vertical direction tocontrol depth (heave). Roll and Pitch are balanced through mechanical design by judiciousplacement of the various components.

The key parameters like depth, maximum velocity, overall system dimension, cablediameter are essentially responsible for overall ROV system design and selection ofactuators and power systems. The parameters are highly interrelated and overall compactsystem design is achieved through an iterative procedure. The basic frame of the ROVhas been analyzed from deflection point of view through finite element analysis. Thesystem is designed for near neutral buoyant with the help of polyurethane based solidbuoyant material.

ROV is interfaced with a slip-ring & winch system with cable handling & cable lengthmeasurement facility and fiber-optic based faster and advanced communication link. TheROV is equipped with camera & lamp and side scan sonar as payload sensors. Severalsensors like Motion Reference Unit (MRU), Doppler Velocity Log (DVL), depth sensorand altimeter are used as feedback devices for the navigation, guidance and control ofthe vehicle.

The present ROV can be operated manually and programmatically in autonomous mode.Position control of ROV represents an important class of control problem. The detaileddynamic formulation is very essential for high velocity applications and also to designsimple controller with a low cost sensor suite. The overall control system has been



decoupled into two sub-systems i.e., planner motion control (surge, sway and yaw) anddepth control. The planner motion of ROV system is thought of as a non-holonomic motioncontrol strategy where two actuators are employed to control three degree’s of freedom.A feedback linearization based path following controller with online gain scheduling hasbeen designed to control the ROV through various paths. The control methodologyadopted for path tracking overcomes stringent initial condition constraints. The simulationresults are very much encouraging and validation through experiments has been plannedto be carried out at the earliest.

ROV-4

Deep water sampling tool design and integration withWork Class ROV - ROSUB 6000

J.Manecius Selvakumar, S.Ramesh, D.Sathia Narayanan, S.B.Pranesh,

E.Chandrasekar, M. Murugesh, Radhakrishnan and C. Jothi


Deep water work class Remotely Operated Vehicle (ROV) namely ROSUB 6000 had beendeveloped by NIOT and qualified for its envisaged functionality during April 2010 at adepth of 5289 m in Central Indian Ocean Basin. ROV is interfaced with multi-beam sonarand scientific sensor to measure water temperature, conductivity, dissolved oxygen,dissolved methane and sound velocity to perform scientific deep water exploration. ROVis equipped with two robotic arms (manipulators) having 5 function and 7 function activityto perform intended activities of sampling. Sampling tool interface with ROV is designerof ROV’s innovative idea to make use of available place, power and hydraulics for effectiveutilization. For sediment sampling ROSUB 6000 is interfaced with in house designedshort corer of 40 cm length with 55 mm diameter which will be attached at the bottomframe of ROV. Whenever ROV touches the sea floor after completion of maneuveringoperation, short corer will collect the sample and bottom core catcher is designed to holdthe collected fine sediments. Same corer with gripper on top of it is used with manipulatorarm for collecting the sample like push corer. Sample collection tray of the dimension 690mm x 320 mm x 250 mm is fixed in front of the ROV and a scoop capable of collecting 750ml by volume is interfaced with 5 fn manipulator. Whenever ROV reaches the sea floor,by using manipulator camera and front pan & tilt camera, we can sample the sea floor bythe scoop mechanism and sample can be stored in the tray. Tray has bottom fine mesheswhere the water can be drained. Using the available spare port of hydraulic pump a slurppump mechanism is designed for sampling the top sediments fine material along with 20mm size biological organisms from the deep sea floor. Collected materials are stored inseparate containers. Apart from sediment sampling, niskin water sampler (capacity 5 l) is


attached in front of the ROV and the robotic arm itself is used as manual trigger insteadof messenger. At appropriate place of important, water sample can be collected for waterquality analysis using manipulator by watching the front camera images in deep watersup to 6000 m. Even though the sample collected cannot hold such a high pressure in deepwaters, as a first step the collected samples can be effectively used for geo-scientific studiesto correlate the visual image observation carried out with cameras at sampling site.Interfaced scientific payloads are tested and qualified during the scientific explorationsea trial for gas hydrate exploration in Krishna-Godhavari Basin in Bay of Bengal at adepth of 1019 m and 1035 m and at Poly-metallic Manganese Nodule site in Central IndianOcean Basin at a depth of 5289 m. Short corer mounted in ROV had sampled the twopieces of manganese nodule from central Indian ocean basin. Integration of slurp pumpis in progress and these sampling tools are useful for many scientific observation. Detailof sampling tools design and integration are discussed in this paper.



ABSTRACTS

THEME-3 OCEAN ENGINEERING,SAFETY AND RELIABILITY


OESR-1

Development of a Ship Weather-Routing Algorithm and ItsApplication to the North Indian Ocean Region

Chinmaya P. Padhy and Debabrata Sen*

Consultant, EDS-E&U/EIT, WIPRO Technologies, Hyderabad, AP-500032, India*Professor, Dept. of OENA & Head, CORAL IIT- Kharagpur, WB-721302, India

Ship weather routing deals with finding an optimal track based on forecasts ofweather and sea conditions and the ship’s characteristics in a particular transit. While theweather parameters that influence ship behavior involve waves, currents and wind, themost important attribute in this connection is the prevailing wave-field in the voyagearea. Historically ship routing used to be based on long-term climatological data on waveconditions. With advances in the weather and climate modeling coupled withavailability of large computing power, it has now become increasingly common to basethe route decisions on weather and in particular wave forecasts. It is now possible to usesophisticated wave modeling software like 3rd generation WAM by ship operators usingon-board computing systems to forecast wave fields using wind and other satellitegenerated data, which can be obtained from specific sites.

The term optimal means a route that optimizes any one or a combination of thefactors such as maximum safety and crew comfort, minimum fuel consumption,minimum transit time etc., depending on the vessel, voyage type and missionrequirements. All these aspects are however influenced by the prevailing weathercondition. Weather routing of ships therefore needs to combine (i) a tool to forecast weather(current, wind and in particular wave) conditions, and (ii) assessment of ship behavior insuch weather conditions, by means of a suitable optimization algorithm.

Dynamics of ships in waves is a complex theme which is usually referred to asseakeeping characteristics of ships. Increase in resistance due to present of ocean wavesfor example is a nonlinear phenomenon. In general, ship behavior under the influence ofwind, waves and currents can be related to a reduction in speed of the vessel. Thisreduction can be of two types (i) an involuntary speed reduction, and (ii) a voluntaryspeed reduction. Typically thus ship routing will be choosing an optimal route dependingon the wave conditions so that the prescribed objective function is optimized (i.e.minimized). Djikstra’s path optimization scheme, which employs optimal control theoryand dynamic programming technique, is used to obtain optimum route in a given randomsea-state.



In applying the present algorithm, an area encompassing the voyage area is divided intosuitable meshes using lat-long coordinates within which the forecast significant waveheight and wave directions using wave-modeling software are generated. The applicationis presently confined to the routes lying in the North Indian Ocean region due toavailability of the forecast wave data using ISRO (Indian) satellite generated information.Based on an assumed form of theoretical wave-spectrum (an ITTC spectrum is usuallyused for ship applications), the optimal route is then predicted by optimizing a suitable‘weight’ or ‘achievement’ function, which is determined depending on the shipbehavior and weather conditions in that grid. The ship seakeeping characteristics arepre-computed over a range of significant wave height, relative heading and speed usingindustry-standard strip-theory based software, which is then interpolated to obtainthe necessary data for each spatial grid. It is shown that the algorithm is general andversatile enough to consider almost all constraints that are required in a practicalapplication, e.g. presence of land boundaries, handling of non-navigable water, presenceof current and wind, storm effects, consideration of voluntary speed-reduction based ona set of seakeeping performance characteristics, etc. A number of results for two ships, asmall 60m coastal vessels and a moderately large 180m cargo ship, are presented todemonstrate various aspects of the algorithm.

Technological advances in satellite altimetry offer the possibility for providing timelyocean information which helps to extend the developed algorithm as a function of timefor optimizing strategic sea routes.

Keywords: weather-routing, seakeeping, ship-behavior in waves, wave modeling

OESR-2

A Study of Reliability and Safety on Dynamic PositioningSystem of ORV Sagar Nidhi

D.Rajasekhar, N.Ravi and Anantha Krishna RaoVessel Management Cell, National Institute of Ocean Technology, Chennai, India.

Sagar Nidhi is an ice class multi disciplinary Oceanography Research Vessel (ORV) ofNational Institute of Ocean Technology, operated and maintained by Vessel ManagementCell. She has class-2 dynamic positioning system which automatically controls the vessel,to maintain its position and heading exclusively by means of active thrust. She is utilisedfor Deep Sea Mining, launching of Remotely Operable Vehicle, Autonomous UnderwaterVehicle, manned/unmanned submersibles and exploration of Gas Hydrates so on thatneeds a highly reliable DP system to carry out the operations for several hours in a


particular station. She is capable of carrying out Geo-scientific, Meteorological andOceanographic research in Indian and Antarctic waters. Drift off or drive off scenariosmakes the need for a highly reliable DP system to maintain the station in worst caseevents. A study has been carried out to get Failure Mode Effect Analysis and reliability ofDP system, which is normally affected by failure of subsystems and its components.Potential failure modes and its impacts on performance of DP system are analysed throughFMEA and subsequent corrective actions were taken. Failure data of subsystems and itscomponents were used in reliability block diagram which inturn used to find the reliabilityof DP system. Two main recommendations were suggested i.e. redundant cooler for bothAzimuth and Bow thruster are provided along with redundant main propulsion coolerwhich improves the overall reliability from the current value of 36% to 68%. Based on thestudy two other recommendations were given to improve the reliability. Use similarmaterial in pipelines to the maximum extent possible to reduce the corrosion and thepossible damage and maintain a standard distance and difference in altitude for theantennas of external sensors which reduces the possible failure of subsystem and therebyimproved life along with increased reliability is achieved. These actions results inimprovement in safety of vessel, onboard machineries, instrument used for scientificresearch and life of onboard scientist and ship staff.

Keywords:- Reliability, Safety, DP systems, Performance Analysis, Thrusters, Redundancy,Risk Priority Number.

OESR-3

Development and testing of model suction piles in theNIOT test pond

Vijaya Ravichandran, R.Ramesh, J.Manecius Selvakumar, Muthukrishna

Babu, G.A.Ramadass and M.V. Ramanamoorthy


Suction anchors are widely used in mooring applications for floating production unitsand find widespread applications in the offshore oil industries. Suction pile anchors arelarge cylindrical (inverted bucket type structure) open at the bottom and closed at thetop. Prediction of the uplift capacity of suction caissons is a critical issue faced by thedesign engineers and rational methods are required in order to produce reliable designs.NIOT has fabricated a prototype suction pile (4.5m long 3m diameter) to develop amethodology for testing and prediction of uplift capacity by carrying out demonstrationtests in 100m water depths. Prior to the trial deployment in the offshore locations, a series



of model tests were conducted in a field setup in NIOT. Objective of these model testswere to develop methodology, design and logistics for suction pile installation & retrievalbefore deployment in offshore locations.

Model tests were carried out in the NIOT test pond using model piles of diameter 0.3m to0.5m by varying the aspect ratio (length to diameter (L/D) ratio). The working platformfor deployment testing is located within the pond. A suction pump capable of 2 barsuction (differential) has been developed for the purpose of installation. Suction pressurerequirements in sands are significantly higher than in clays. Estimates of suction pressuresin sand indicate that higher the diameter of the pile, lower is the suction pressure(differential) requirement. However, in sands, higher suction pressures lead to increasedseepage thereby requiring pumps with high flow rates in order to develop the requisitedifferential pressure. Presently PSG make pump with flow rate of 180 litres/min isproposed to be used. For a given suction pressure, the pump flowrate needs to be inexcess of the seepage in order to achieve penetration. Alternatively, the suction pressuresmay be reduced in order to lower the seepage thereby suiting the pump capacity. Twovents of 65mm diameter are provided at the top for applying suction pressure and delivery.One way flow is maintained through solenoid valves. Additional vents are provided forremoval of water during lowering.

The instrumentation consists of thrusters for ensuring verticality and preventing rotationof the anchor during installation, pressure transducers for measuring suction pressure atthe vent and pore pressures within the anchor. Depth sensors and altimeter for measuringrate of penetration and pan and tilt sensors equipped with cameras and lights for checkingverticality are also installed. The electronics and pump shall be housed on a pump skidwhich will be connected to the prototype through an emergency release system duringdeployment. Since the electronics, instrumentation and electrical components are to beprotected from exposure to seawater and high pressure at 100-200m water depths, theyshall be housed in pressure cases.

Initial tests indicated a pullout capacity of 785kg for a 500mm diameter 750mm long pilewhile a 300mm diameter 450 long model (L/D=1.5) provided a pullout capacity of 285 kg.For L/D=1 for 300 mm diameter pile, the pullout capacity was 185 kg, while for L/D=2, thecapacity was 350 kg. This shall be verified with numerical model tests.


OESR-4

A New Concept and Design of a Low Cost WaveEnergy Converter

Pradip Deb Roy and Debabrata Sen*

Dr. B. C. Roy Engineering College, Dist. Burdwan, (West Bengal)

*Dept. of Ocean Engineering & Naval Architecture, IIT, Kharagpur, West Bengal

Ocean wave is a vast source of energy which is yet to be fully utilized for the mankind,although at present there exist few methods of exploiting kinetic energy of the wave. Inthis work, an innovative design of a wave energy converter (WEC) is proposed where thekinetic energy obtainable from the ocean surface wave is converted in the form of potentialenergy which can subsequently be used for any other useful purposes. The initialconfiguration and the basic principle of application of this device are tested through simpleexperimentation. A propagating wave imposing normal force on a submerged verticalthin plate of size 0.8×0.6m causes it to oscillate in the surge direction, and a mechanicalsystem is devised which transforms this motion to potential energy by raising water to acertain height. Two compression spring of spring coil diameter d

s = 2mm is attached with

the plate at the back side and the plate moves in the direction of ocean wave against thetwo compression springs. The plate is connected to the piston of size 0.1m diameter, bymeans of a piston rod of size 0.01m. Piston moves with the motion of the plate in a closedfitting cylinder of internal diameter 0.1m and external diameter 0.12m. Suction anddelivery pipes with suction valve and delivery valve are connected to the cylinder. Thesuction and delivery valves are one way valves which allow the water to flow in onedirection only. Suction valve allows water from ocean to the cylinder and delivery valveallows water from cylinder to delivery pipe.

The system is extremely cheap and therefore viable even if the energy transformation isonly a small percentage of available wave energy. This can be deployed over large partsof coastal areas having a large and poor population, and the energy stored in form ofpotential energy can be used for electric power generation driving small motors likeirrigation pumps. This paper presents the experimental investigation demonstrating thevalidity of the concept.



ABSTRACTS

THEME-4 SONAR TECHNOLOGIES


ST-1

Finite Element Analysis of Vibration Isolation Module withNylon Rope Strength Member

Beena.B.R*, M. Sabu Sebastian, Manojkumar, S.Jithu

Naval Physical and Oceanographic Laboratory, Kochi, India

*Mar Athanasius College of Engineering, Kothamangalam, Kerala, India

Vibration isolation modules (VIMs) are used in underwater towed sensor arrays to controlthe mechanically induced tow noise. In general vibration isolation module has a gel filledcylindrical construction with polymeric outer hose and tensioned polymeric strengthmember running between end connectors. In the existing configuration of VIM Kevlarfabric is being used as the strength member. This paper focuses on the performanceprediction of VIM with Nylon rope as an alternative strength member. The study includesviscoelastic characterization of Nylon rope, estimation of longitudinal vibration responseby finite element analysis and experimental validation of the response.

The viscoelastic properties of the major constituent, the Nylon rope, are modeled usingdiscrete parameter models. For comparative purpose, three parameter and five parametermodels are employed. The finite element model of VIM in ANSYS mainly comprises ofCOMBIN 14 discrete parameter models for Nylon rope and SOLID 185 viscoelastic elementfor polymeric hose and gel. The viscoelastic parameters of Nylon rope strength memberare determined through semi-empirical means from strain rate tests at different preloadsand at different strain rates. Validation of finite element estimate is done by impact tests.

The paper also presents a comparison between (i) the analytical and experimental results,(ii) the performance of three parameters and five parameters model of Nylon rope, (iii)performance of VIM with Nylon strength member and Kevlar strength member.

Key words: VIM; underwater towed acoustic sensor; ANSYS finite element model; Nylonrope; strength member; viscoelastic.



ST-2

Reverberation Measurement of Acoustic Tank

A.Malarkodi and Dhanalakshmi


The accuracy of acoustic measurements in the acoustic tank depends on the reverberationdue to the boundaries. When an acoustic source emits the signal in the measurementtank, these signals are reflected by the walls, the surface and the bottom. The multiplereflections give rise to the reverberant field. The acoustic energy depends on the powerof the source and the losses on the walls. In general reverberation time can be defined asthe time in seconds for a sound energy to drop 60 dB below its initial value.

The reverberation study was carried out at the Acoustic Test Facility (ATF) of NationalInstitute of Ocean Technology by using the standard projector transducer of knowncharacteristics. The source transducer was driven with different frequencies like 1 kHz, 5kHz, 10 kHz, 20 kHz and 40 kHz of sinusoidal signals and also driven with white noise.The reverberated field is assumed as homogeneous in space and isotropic. Thehomogeneity of the reverberated field was verified by taking the measurements at differentlocations of the tank simultaneously. At time t=0, the sound pressure level at differentpositions of the tank was measured using data acquisition system with the samplingfrequency of 102.4 kHz. Then the slope of the mean square value was found numericallyusing the sampled output voltage with a sampling frequency. The suitable time ofintegration was chosen in order to average the signal and to get the decreasing slope. Byapplying a linear regression the reverberation time was determined. The averagereverberation time of the acoustic tank measured was in the range between 350ms and400ms. This study will be useful for better acoustic measurement in the acoustic tank.

ST-3

Application of Wavelets for Analysing Ship Noise fromShallow Water Ambient Noise Measurements

M. Ashokan, P. Edwards Durai and K.Nithyanandam

National Institute of Ocean Technology, Pallikaranai, Chennai, India.

Time series measurements of shallow water ambient noise have been made for a week,off Tuticorin by deploying an autonomous ambient noise measurement system. Thepreliminary analysis of measurements showed predominantly the noise field is due toship crossing other than the wind noise. This paper presents the work carried out in


extraction of specific ship noise sources by application of wavelet transforms as waveletdenoising algorithm has finer decomposition and reconstruction properties in thefrequency domain. The frequency localization of wavelet denoising technique is used toefficiently localize the ship noise.

The methodology involves study of spectrogram of the noise measurements initially andthen application of wavelet decomposition (down sampling). The optimal thresholdvalue for the wavelet coefficients is calculated and this yields 2(2n-1) levels to denoise thesignal. From the wavelet coefficients, reconstruction (up sampling) of the decomposedsignal is done. Finally the spectrogram of the reconstructed signal is studied. The resultsshow clearly the narrow band frequency components of shipping noise present. Thishas applications in finding different types of boats/ship noise and the technique is appliedto different data sets for finding such sources.

ST-4

Acoustic Intensity Fluctuations Induced by EnvironmentalParameters in Coastal Waters

Sanjana M C, G Latha and A.Thirunavukkarasu


In coastal regions various factors affect the propagation of short range acoustic signalssuch as the wind, tidal effects, off shore currents and even river outflows. Shallow waterwaveguide is also characterised by site-specific source nature, bathymetry, sedimentproperties and sound speed profile. A vertical linear array of hydrophones (frequencyband 10 Hz - 10 kHz) integrated with mechanical fixtures and data acquisition systemswith necessary power pack has been deployed off Cochin to study the ambient noisecharacteristics at 32 m water depth with a lossy bottom. Data have been collected forlonger periods covering wind speeds of 2 - 6 beaufort and the entire spring-neap tidalcycles. Sound velocity profiles and bottom sediment samples measured at the sitecharacterize the water column and the ocean bottom respectively. Due to heavy riverinflux of fresh water at the site, the sound velocity profile exhibit a well defined negativegradient. The bottom is clay (soft bottom) which can lead to absorption of acoustic intensityinto the sediment leading to a decrease in reflected acoustic rays. Under these conditionspropagation to large distances will be associated with large losses in acoustic energy. Thecritical angle of propagation determined theoretically in this case is found to be ±15pwith respect to horizontal representing low order trapped modes.



In this paper the noise received is compared with respect to the propagation characteristicsin the water column, and noise intensity and direction of arrival is determined for differentenvironmental conditions such as a downward refracting sound velocity profile, anupward refracting sound velocity profile and an iso-velocity profile. For an upwardrefracting sound velocity profile, noise propagation will be along the surface and willlead to predominant noise arrival from the top whereas for downward refracting profile,rays will travel along the bottom and hence noise arrival will be from the bottom. Theeffect of wind forcing on the water surface and movement of water due to tides causesvariability on the acoustic properties, which have also been investigated here. It is alsoseen that fluctuation in noise property arise due to small and large scale environmentalphenomenon which includes sound speed profile fine structure, small scale turbulenceand frontal zones.

ST-5

Measured Broadband Reverberation Characteristics inDeep Ocean

Baiju M Nair , M Padmanabham and M P Ajaikumar

Naval Physical and Oceanographic Laboratory, Kochi, India

Broad band reverberation measurements were collected in deep water (2067m) off Vizag.TNT scare charges (0.450kg) were used as sound sources which were expended from theship. The signals were recorded using two hydrophones deployed from the ship. Thesound speed profile exhibits 63m duct with a limiting ray angle of about 4.47o and lowercut off frequency of 177 Hz. One third octave band analyses using multirate filters andtime frequency analysis (spectrogram) were done to study the reverberationcharacteristics. A sudden fall of 10 dB near ~12-13s on the reverberation characteristic indeep water is related to the effect of sound speed profile and water depth. This effect iscorrelated with ray theory based model and the results are presented.


ST-6

Matlab Code for Tow Characteristics of anUnderwater Towed System

Ambily Vijayan*, K Ajith Kumar, K Sudarsan

Naval Physical and Oceanographic Laboratory, Kochi, Kerala, India

*Mar Athanasius College of Engineering, Kothamangalam, Kerala, India

Cable scope, cable tension, cable angle, body depth & body trail for a given speed ofvessel are the typical parameters that play an important role in the preliminary design ofany underwater towed system. A MATLAB code is developed based on the theory of twodimensional steady state analysis of tow cable. It is assumed that the cable lies in theplane containing the direction of gravity and that of the towing ship’s motion. The freesurface effects are neglected and the cable is uniform, moving with constant horizontalvelocity. A Graphical User Interface developed makes it user-friendly and quickvisualization of the results. The code is useful and handy for any operator of an underwatertowed system during field trials.



ABSTRACTS

THEME-5 OCEAN OBSERVATION SYSTEMS


OOS-1

Analysis on Under-water Seismic Event on June 12, 2010recorded by Indigenous Tsunami Early Warning System

M. Arul Muthiah, Tamil Mugilan, R.Venkatesan


This paper presents the work carried out on the indigenous development of dataacquisition and processing system for the Tsunami buoy with bottom pressure reorderdeployed by Ocean Observation Systems of National Institute of Ocean Technologyunder the Ministry of Earth Sciences of Government of India. The indigenouslydeveloped tsunami buoy data acquisition / processing system has interface with theBottom Pressure Recorder system, Surface Buoy Acoustic Modem, Inmarsat satellitecommunication Modem etc. The system was deployed on 14 th April 2010 in Bay ofBengal at the location TB04 (09 °18.5768’N , 089 ° 27.0692’ E). The Bottom PressureRecorder (BPR) measures the instantaneous pressure at the sea bed continuously,using 15 second samples and averages the data. In normal mode, at regular intervals(for every 1 hour), the BPR will telemeter an acoustic data message to the surfacemodem with a time stamped pressure reading along with some status parameters.The Bottom Pressure Recorder compares every sample to a predicted value that iscalculated from the previous pressure readings. If the difference between the twoexceeds a preset threshold value, the BPR enters into alarm mode and starts totelemeter every sample every 5 minutes for a period of 3 hours, after which it returnsto the normal mode. The system was functional in the sea and transmitting data everyone hour. On June 12, 2010 when an undersea earth quake occurred, it captured thesignal, switching to tsunami mode for three hours and the data recorded by the systemhas been analyzed. Comparison of the data with the nearby NOAA Buoy (Station:23401) has been made and results are presented in this paper.



OOS-2

Analysis of Antenna placement on Data Buoy Systems forINMARSAT Satellite Communication

K.Ramesh, M. Arulmuthiah, P. Murugesh and R.Vengatesan


Moored buoys have been deployed to record and report a wide range of sub-surface,surface and atmospheric conditions in the Indian ocean. The real time data from theseplatforms used for advance scientific research, support weather and marine forecasts,and aid climate modelling and prediction. Data from the platform are transmitted toshore station with help of INMARSAT satellite. The INMARSAT antenna fortransmission is kept in a mast assemble for better signal strength, buoy mast assemblyis prone to get vandalized frequently, this paper describe the study conducted onthe placement of antenna inside the FRP hood to protect the antenna from vandalismand its consequences. An experiment was conducted with different strategies, inwhich one buoy was deployed with antenna inside the FRP hood, and another onewas deployed with antenna placed in the mast assembly. This study was carried outwith the real time data received from the buoy. The signal strength of the antenna isco-related with buoy reference North and INMARSAT satellite position. This paperdiscusses further on the strategies to overcome the data transmission problem withthe option of antenna placement inside the FRP hood to reduce the incidence/consequence of vandalism.


OOS-3

An ARGO Based Study on the Water Mass Characteristics ofthe Bay of Bengal and the Arabian Sea

Sourav Sil, Sudip Jana and Arun Chakraborty

Centre for Oceans, Rivers, Atmosphere and Land Sciences (CORAL),

Indian Institute of Technology Kharagpur, Kharagpur, India

This study presents the differences of the water mass characteristics of the two semienclosed basins: the Arabian Sea (AS) and the Bay of Bengal (BOB) located in the northIndian Ocean. The work based on the Array for Real-time Geostrophic Oceanography(ARGO) datasets for the years 2003 to 2009. Before being used for the study, theseARGO data passed through several quality control procedures such as position onland test, pressure increasing test, regional range test, spike test, gradient test, densityinversion test and finally visual inspection for the suspected data. The temperature-salinity (T-S) diagram indicates the existence of the high saline water mass in the AS.The vertical structures of salinity show that the salinity increases with depth for theBOB but for the AS it increases up to certain depth and then again decreases. Thedepth with maximum salinity (called as core depth) varies from 20m to 80m for theAS. The monthly variation of the core depth shows that it deepens when the salinity isless at the surface. The nature of the annual cycle of surface temperature is similar forthe BOB and the AS. But the surface of the BOB is warmer than that of the AS throughoutthe year expect May. The monthly variation of the surface salinity are similar for boththe basins. But surface salinity of the AS is higher than that of the BOB throughout theyear. The maximum surface salinity for the AS is found to be 36.5 psu while for theBOB it is 33.4 psu. The monthly variation of surface density is analogous for these twobasins but for the AS is higher than that of the BOB.



OOS-4

Coastal wave measurement using HF Radar

Manu P. John, Rajnish Antala, Sisir K. Patra, B. K. Jena

National Institute of Ocean Technology, Chennai - 600100

Measurement of waves at different locations, spatially, for a complete study of a regionis not feasible as the effort and the cost for installing individual instruments over aregion is enormous. High Frequency (HF) radar can solve this problem to a certainextent by remotely monitoring the wave activity over a region near to the coast. HFRadar is a tool for synoptic on-line mapping of surface current fields and the spatialdistribution of the wave directional spectrum. In this study we check the possibilityof replacing the Wave rider Buoy with HF Radar along the Tamil Nadu region.

Wave data from two HF Radar sites and two Wave rider buoy along the Tamil Naducoast is used for the study. In the Indian scenario the average wave height is normallybetween 1 to 2 m in height along the entire coast, except during the monsoon period.During the monsoon months the wave height reaches to about 2- 3 m with a mixedinfluence of swell and sea waves. The installed HF Radars are quite adequate to detectthe high wave activity. But it is insufficient to detect wave heights less than 1.4 m.The HF Radar wave data obtained during various periods has been analyzed and itco-relates satisfactorily with the maximum wave height (Hmax) obtained from theWave rider buoy. Thus making it an efficient method to monitor high wave activityalong the region covering a large domain of more than 100 km even during a cycloneperiod, during which a Wave rider buoy may be hard to manage. The measurementof wave height of about 0.4 m can be achieved by using HF radar with high resolutionmode.


OOS-5

Inter-comparison of Wave Measurement by Accelerometerand GPS Buoy in Shallow Water off Cuddalore,

East Coast of India

Sisir K Patra and B K Jena


The performances of Accelerometer and GPS buoy were tested off Cuddalore at 30 mwater depth during 15 to 30 November 2010 by mooring the buoys 225 m apart from eachother. Compared to other wave parameters, results of regression analysis on significantwave heights (Hs) shows a better correlation (correlation co-efficient R = 0.94) betweenAccelerometer and GPS buoy. A lesser co-efficient of R = 0.85 and 0.77 were resulted forwave direction and peak wave period (T

p) respectively. The waves were basically

approaching from two directions, i.e. two wave forms or wave fields. One wave field wasfrom around 80° and other was 140°. However, the wave directions averaged within eachfield over the observation period individually are in good agreement with both buoys. Itwas noticed that the predominant directions reported by these buoys were not identicalalways. Even though the buoys were placed at identical water depths (~ 30 m) and inclose proximity (~ 225 m), they were reporting different predominant directions. Thecorrelation seems low because it was determined to a large extent, with waves fromdifferent directions. Comparatively, zero up-crossing wave period (T

z) shows a better

agreement with Tp, which may not be a robust parameter due to its dependence on

estimation of spectral peak.



ABSTRACTS

THEME-6 OCEAN REMOTE SENSING & APPLICATIONS


ORSA-1

Validation of Satellite Derived Precipitation Data

Abdulla C.P. and M.R. Ramesh Kumar

Physical Oceanography Division, National Institute of Oceanography, Dona Paula, Goa

Recent progresses in remote sensing technology is very important in the hydrologicalstudies. The Tropical Rainfall Measuring Mission (TRMM) is being flown by US andJapan to improve our quantitative knowledge of the 3-dimensional distribution ofprecipitation in the tropics. TRMM has a passive microwave radiometer, the firstactive space-borne Precipitation Radar (PR), and a Visible-Infrared Scanner (VIRS),plus other instruments. TRMM provides precipitation product at monthly to 3-hourlyprecipitation fields with 0.25x0.25 degree resolution. Global Precipitatin ClimatologyProject(GPCP) is another precipitation dataset available at one-degree resolution.TheGPCP Data consists data from over 6,000 rain gauge stations, and also fromgeostationary and low-orbit infrared, passive microwave satellite data, and soundingobservations have been merged to estimate monthly to daily precipitation fields. Inthe present study an attempt has been made to validate the satellite merged dailydata product from TRMM and GPCP with a) Indian Daily Weather Report (IDWR)precipitation data for island stations (Aminidivi and Minicoy in Arabian sea, andPortblair and Carnicobar in Bay of Bengal) and b) RAMA buoy data for seven stationslocated in Indian Ocean. Analysis shows that TRMM has higher correlation than GPCPwith both IDWR and RAMA datasets. From the time series plots of TRMM 3-hourlydata and RAMA bouy 3-hourly data it was found that TRMM data can capture thediurnal variability of precipitation shown by RAMA data.

Key words: Satellite data, Validation, TRMM,GPCP.



ORSA-2

Sea level and Eddy Kinetic Energy Variability in theBay of Bengal from altimetry

K.Palanik Kumar and P.P. Saheed*

Institute of Remote Sensing Anna University, Chennai.

*National Institute of Oceanography, Dona Paula, Goa.

The sea level and eddy kinetic energy variability of Bay of Bengal (BoB) at different timescales (monthly, seasonal and annual) over 17 years (1993-2009) was studied using satellitemerged altimetry data (T/P+ERS1/2+Jason-1/2+EnviSat).

We find that the sea level rise in BoB is about 2.5 mm/year, which is within the averagedvalues of sea level rise for the global ocean (Xuhua et al, 2007, Ablain et al, 2009). Themonthly mean sea level anomaly is maximum (9.8cm) in December 2008 and minimum (-10.9cm) in January 1998. In 2008, the BoB experienced a number of intense cyclones andthe year 1997-98 is characterised by an active El Nino event (Chen et al 2009, Chellappanet al 2009). SLAs (both positive and negative) during December of all the years (1993-2009) show high fluctuations associated with warm and cold core eddies. The minimumSLA was observed in March/April. This annual cycle variation in sea level is due to thesteric-effect - increase in the volume of ocean without change in the mass (Caballero etal., 2007). The intense variability in sea level along the east coast of India and around Sri-Lankan coast is due to the existence of western boundary currents (WBC).

The eddy kinetic energy (EKE), in turn, is found to be high during northeast monsoon(November-January) and southwest monsoon (June to September) seasons. During thenon-monsoon period, EKE shows a weak positive trend. During the El Nino event(December 1997 to January 1998), the EKE is found to be high. High EKE during northeastmonsoon season may be the reason for high SLA variability in the Bay of Bengal. Overallanalysis shows that mean EKE ranges from a minimum value of 45.55 (cm2/s2) to amaximum value of 2780.6 (cm2/s2), with an average value of 461.5 (cm2/s2). According toSharma et al (2010), instability in the monsoon currents, the Rossby wave propagationfrom the eastern BoB and wind stress curl are the main causes for the EKE variability inthe BoB. We have further analysed SST and wind stress data to substantiate our study onthe sea level and EKE variability in BoB.

Keywords: sea level anomaly, eddy kinetic energy, El-Nino, Rossby waves, Bay of Bengal


ORSA-3

Potential Fishing Zone advisories-Are they beneficial to the coastal fisher folk?

Kerala experience

V.N.Pillai and Preetha.G.Nair

CMFRI, Kochi -682018

Innovative validation of Potential Fishing Zone (PFZ) advisories generated by theIndian National Centre for Ocean Information Services (INCOIS) along Kerala coastduring the period 2003-2011 revealed positive relationship between PFZ advisoriesand occurrence/ abundance of commercially important pelagic fishes such as Oilsardine, Indian mackerel, Anchovies, Carangids and Coastal Tunas. The usefulnessof PFZ advisories, the only short term marine fishery forecast available in the country,for artisanal, motorized and mechanised sector fisherfolk towards obtainingcomparatively higher catch per unit effort for the above mentioned major pelagics isproved beyond doubt through the results of more than 100 controlled experimentsconducted onboard more or less identical commercial fishing vessels operating moreor less identical fishing gear along Kerala coast.

Key words: Remote Sensing, Potential Fishing Zone, Validation, Oil sardine, Mackerel,Anchovies, Carangids, Coastal Tunas.

ORSA-4

Sea Surface Temperature estimation for condenser coolantdischarges from a power plant using satellite data

C. Anandan, R. Kaviyarasan, M. Sankar Ram, P.Sasidhar and

V. Balasubramaniyan

Safety Research Institute, Atomic Energy Regulatory Board, Kalpakkam – 603 102

Power plants are generally located on seacoasts owing to the ready availability of abundantseawater for condenser cooling. Condenser effluents from coastal power plants have thepotential to impart thermal and chemical stress and, therefore, may pose environmentalproblems to the receiving water body. A study has been taken up on sea surfacetemperature (SST) studies by employing multi-dated satellite thermal infra-red imageries.The aim of the present study is to identify the temporal characteristics of the thermalplume signature around a coastal NPP site, Kalpakkam due to condenser coolant



discharges using satellite derived Thermal Infra Red (TIR) image. The present workincludes processing and conversion of Satellite data obtained from USGS website to deriveSea Surface Temperature (SST) by employing suitable algorithms. This SST map helps toplot thermal plume characteristics with respect to season. The study also includesvalidation of derived SST by comparing with field measured SST values.

ORSA-5

Upwelling in the southeastern Arabian Sea as evidenced byEkman mass transport using wind observations from

OCEANSAT–II Scatterometer

Smitha, A., Ajith Joseph, K., Chiranjivi Jayaram* and A. N. Balchand**Nansen Environmental Research Centre (India), Kochi

*Indian National Centre for Ocean Information Services, Hyderabad

**Department of Physical Oceanography, Cochin University of Science & Technology, Kochi, India

Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense,cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer,nutrient-deplete surface water and enhances biological productivity. In the presence ofwinds, often along coasts, the classical Ekman phenomenon occurs wherein, divergenceor convergence in the Ekman layer causes upwelling or downwelling in the ocean.Negative values of the Ekman mass transport indicates an offshore movement of waterand related upwelling. In this context, Arabian Sea is one of the highly productive seas inthe Indian Ocean region where coastal upwelling occurs during summer monsoon (June–September) season. Off the southwestern coast of India, upwelling starts even before theonset of the summer monsoon and continues till it ends in September. In this paper wehave estimated the monthly Ekman mass transport in the southeastern Arabian Sea usingscatterometer data from Oceansat-II satellite. Level 3 daily wind data at 50kmx50km spatialresolution for the period from November 2009 to October 2010 has been used for thecomputation of Ekman mass transport. The intra seasonal variability of Ekman masstransport has been analysed to make an attempt to explore the dynamics behind theoccurrence of coastal upwelling in this region. The prominent region of upwelling alongthe southwest coast of India has been identified between 8o and 14oN latitude.

The strongest offshore Ekman mass transport was observed during August due to thefavourable wind conditions.

The maximum offshore Ekman transport of about -2000kg/m2/s was located off thesouthern tip of India. Very weak offshore Ekman transport was observed during the pre-monsoon months of March and April 2010 when the wind is weak and variable. Moderate


offshore transport was observed along the southwest coast between December 2009 andFebruary 2010. At the same time region off the southern tip of India and the open oceanwest of 70oE experienced strong offshore transport. Besides, comparison of Oceansat-IIscatterometer wind with ASCAT scatterometer wind has been carried out and it was foundthat they are in good agreement.

ORSA-6

Sources of Errors in the Measurements ofUnderwater Profiling Radiometer

Noah Silveira, T. Suresh, Madhubala Talaulikar, Bhushan Pednekar,

S.G.Prabhu Matondkar, Aneesh Lotlikar*

National Institute of Oceanography, Goa

*Indian National Centre for Ocean Information and Services, Hyderabad, India

Surface optical parameters required for ocean color satellite applications need to bemeasured with high accuracy and errors within the permissible limits. These stringentrequirements demand careful measurements of optical parameters. There are varioussources of errors from the measurements of optical parameters using a radiometer, whichcan be classified as mode of deployment, instrument and environment. The errors fromthe deployment are primarily from the ship and superstructure shadows. The instrumentcould be a source of error arising from its self-shadow, drift in the calibration andtemperature effects. There could be large errors, which at times may be unavoidable toenvironment factors such as wave focusing at the surface layers, sea state conditions whichmay affect the tilt of the instrument, atmospheric conditions such as cloud cover, solarelevation, wind and rain. The radiometric optical data in water could also get affecteddue to Raman scattering and fluorescence effects. Here we discuss the above sources oferrors and how they could be minimized. From the measurements carried out in the coastalwaters off Goa and Arabian Sea using the hype-spectral radiometer, we propose simpleprotocol to measure the data and also screen the erroneous data measured from theradiometer.



ORSA-7

CHANGE DETECTION STUDIES OF RAMESWARAM ISLAND, INDIA USING

REMOTE SENSING AND GIS

R.Gowthaman, G.S. Dwarakish*, V. Sanil Kumar and P. Vinayaraj

National Institute of Oceanography, Dona Paula, Goa.

*Department Applied Mechanics & Hydraulic, National Institute of Technology, Surathkal, Mangalore

Rameswaram Island, the geological formation of coral atoll with huge sand cover situatedbetween India and Srilanka plays a vital role on the processes of exchange of littoral driftbetween the east and the west coast of India. Due to the Sri Lanka Island, the Palk Baysituated north of Rameswaram Island is sheltered and siltation is observed. The shorelineand land-use/land cover changes is studied using the Indian Remote sensing satellite(IRS-1C, IRS-P6) Linear Image Self-scan Sensor (LISS) III data during 1998 and 2008. TheGIS technique is used to quantify the erosion and accretion. The base maps are scannedand registered using ERDAS image software and map composition is done using ArcGISsoftware.

A comparison between the Survey of India toposheet of 1969 and satellite data of 1998indicates that during these years about 1.8 km2 erosion and 5.2 km2 accretion has occurred.During 1998 to 2008 erosion of 0.86 km2 and accretion of 1.7 km2 is found. The Land-use/land cover assessment based on visual interpretation during 1998 and 2008 indicateswater body of 178 & 170 km2, sand features of 32 & 47 km2, vegetation of 29 & 26 km2 andcoral reef of 5 and 10 km2 . The study shows that the sand spit along Dhanuskodi wasgrowing.



ABSTRACTS

THEME-7 OCEAN STATE FORECASTING (OCEAN MODELING)


OSF-1

Modeling of Coastal Inundation due to Storm Surges:A case study for Andhra Coast

P L N Murty, A D Rao and S K Dube

Centre for Atmospheric Sciences, Indian Institute of Technology Delhi

Numerical ocean models are as an essential tool to predict a spurt in the sea level riseover the region of cyclone landfall and the associated inland extent of flooding that couldbe generated along the coastal stretch. For this purpose an advanced two-dimensionaldepth-integrated (ADCIRC-2DDI) circulation model based on finite element formulationis applied for the Andhra coast to simulate storm surges and associated coastal inundation.Using the model, validation of surges and associated inundation generated by December2003 cyclone which had landfall near the Machilipatnam coast is carried out. Thesimulations exhibit a good agreement with available observations from the post-stormsurvey reports. This region is known for its high vulnerability to cyclonic storms as it isbeing located in the low-lying area and its off-shore region is very shallow along the eastcoast of India. Hence, it is advocated that this region could be more prone to inlandinundation from the produced surges. In the present experiment, a peak surge of about2.0 meter is generated by the 2003 December cyclone. The model simulates the associatedmaximum inland inundation of about 4 km in the region. The surge dependence on thetranslation speed also has been investigated. Accordingly, it suggest that the peak surgetends to drop as the translation speed increases.

OSF-2

Numerical simulation and mechanism of mini-cold pool offthe southern tip of India during summer monsoon season

A D Rao and D K Mahapatra*

Centre for Atmospheric Sciences, Indian Institute of Technology Delhi*National Centre for Medium Range Weather Forecasting (NCMRWF), NOIDA, Uttar Pradesh

Study of AVHRR5 SST data suggests that the mini-cold pool (MCP) off the southern tipof India (STI) and its intrusion into the south central Bay of Bengal (BoB) during thesummer monsoon season is extended up to September in contrast to the earlier studieswhich suggests that it sustains till August. Numerical experiments are conducted to studyand ascertain the mechanism associated with it. The mechanism that governs theoccurrence of this MCP is not only due to upwelling caused by the divergence in the



near-surface circulation off STI but also due to the advection of the cold water from thewestern Arabian Sea (AS) region and upwelled water from the southwest coast of India.This explains the extended cooling upto September at par with August. Moreover, theintra-seasonal and inter-annual variability of this MCP suggests that the drivingmechanism for this is primarily the divergence of near surface circulation resulting inupwelling, advection and wind induced mixing. The cold water associated with MCPintrudes gradually into the south central BoB by the Summer Monsoon Current (SMC)right through September. The importance of the study lies in the fact that the formationand dissipation of MCP is related to the active/break phase of summer monsoon.

OSF-3

Numerical Hindcasting of Storm Waves during LAILACyclone using reanalyzed wind fields

S.V.V. Arun Kumar, K.V.S.R. Prasad, K.V.K.R.K. Patnaik, Ch. Venkata Ramu,

P.S.N. Acharyulu, D. Mani kumari and A.P.V. Apparao

Andhra University, Visakhapatnam

The cyclonic storm Laila (means night in Arabic) is the first cyclonic storm to affectsoutheastern India in May 2010 since the 1990 Andhra Pradesh cyclone. It is the firstsevere tropical cyclone of the year 2010 that happened over North Indian ocean. Lailawas developed on May 17 in the Bay of Bengal from a persistent area of convection andintensified as it tracked northwestward, became a severe cyclonic storm on May 19. Thenext day, it crossed south Andhra Pradesh coast near Bapatla in Andhra Pradesh between1100 & 1200 UTC and weakened into a cyclonic storm at 1200 UTC close to Bapatla(Latitude 16.0º N & Longitude 80.5º E), and it later dissipated over north coastal AndhraPradesh. It caused flooding and damage along its path. It is the worst storm to hit AndhraPradesh over the last 14 years. Wave prediction is an important concept useful for naval,ship-routing and other offshore based industries. Waves are the immediate energy carriersthat effect the coasts worsely during severe weather conditions and therefore veryimportant to be predicted well in advance. There are several numerical models availablefor this purpose which needs predicted winds for forecasting the waves. The performanceof the numerical model not only depends on the model elements but also on the accuracyand resolution of wind data. In this paper, we attempted to hindcast waves over IndianOcean (30S to 30N and 30E to 120E) during the propagation of the severe cyclone LAILAusing a Spectral wave Finite volume model. The 10-meter wind data was retrieved fromECMWF Interim re-analysis and NCEP/NCAR reanalysis for the study period. These windfields were different in both spatial resolution as well as accuracy. The variation in wind


wave, swell wave and other spectral characteristics are addressed at specific locationsi.e., Chennai, Bapatla, Visakhapatnam and Paradeep stations in relation to the cycloneprogression and development. The model is calibrated and the results are validated withbuoy data from Pondicherry and Visakhapatnam. Statistical tools such as standard biasand RMS errors were applied for estimating the model performance. Results suggeststhat ECMWF reanalyzed wind data is giving better hindcast compared to NCEP data.

Keywords: Cyclone LAILA, wave hindcasting, MIKE 21 model, ECMWF and NCEPreanalysis.

OSF-4

Numerical simulation of cyclone movement using HighResolution Regional Ocean Model: A Case Study for the

Cyclone Mala (24th - 29th April, 2006)

Bishnu Kumar and Arun Chakraborty

Indian Institute of Technology Kharagpur, Kharagpur, India

The prediction of cyclone track in the Bay of Bengal (BOB) is yet not lucid although it is acyclone prone basin. This work presents the track of the severe cyclonic storm Mala (24th

– 29th April, 2006) which was the strongest tropical cyclone struck over the BOB region.The Regional Ocean Modeling System (ROMS) has been setup for the BOB basin with 18km × 18 km horizontal resolution and 32 vertical levels. The initial condition for the modelsimulation is derived from objective analysis (OA) field of the recent Real-time GeostrophicOceanography (ARGO) and the Simple Ocean Data Assimilation (SODA) package (SODAv2.0.4) for 23rd April, 2006. The model is forced from 24th April, 2006 (starting date of theMala) with the fields a) wind speed and wind stress components from QuikSAT, b) seasurface temperature (SST) from TRMM-TMI, c) air temperature at 2m, specific humidityat 2m, net surface heat flux and net surface shortwave radiation flux from WHOI OAflux data (version 3), d) air density and evaporation-precipitation are taken formComprehensive Ocean-Atmosphere Data Set (COADS) and e) sea surface salinity (SSS),derived by OA field of the ARGO datasets and the SODA package.

The movements of the cyclone have been analyzed from the oceanic variables sea surfaceheight anomaly (SSHA), cyclonic heat potential (CHP) and 26 °C isothermal depth (D

26)

from the model simulation. The model simulated currents show that two adjacent cycloniceddies formed in 24th April, 2006 centered at 91° E; 15.5° N and 89.6° E; 9.0° N. This isfavorable condition for depression as the eddies hold CHP of the order of 50 ×107 J/m2

and there are good correlations (> 0.9) of CHP with SSH and D26. In next day the southern



eddy shifted to 89.4° E; 9.5° N to form deep depression as supported by the IndianMeteorological Department (IMD) (estimated at 90.5° E; 9.5° N). Then its center movedto the northeast and intensified into a cyclonic storm Mala in the next day with centre at90.5° E 13° N (IMD estimated at 90.5° E; 12° N). In 28th April, a cooling of the sea surfaceof up to 1.3 °C is observed on the Mala track which is due to the mixing of the sub-surfacecold waters. There are also drop-off in CHP and D

26 by 25 ×107 J/m2 and 22 m respectively

from the initial day. In the next day Mala rapidly intensified at northeast to make it thefirst category 4 cyclone in the 21st century in the BOB basin.

Keywords: Cyclone, Mala, ROMS, CHP.

OSF-5

Indian Ocean Simulation Results fromNEMO Global Ocean Model

Imran M. Momin, Ashis K. Mitra, D. K. Mahapatra and L. Harenduprakash

National Centre for Medium Range Weather Forecasting (NCMRWF), Noida

Nucleus for European Modeling of the Ocean (NEMO) is a state-of-the-art modelingframework for oceanographic research, operational oceanography, and coupled modelingfor climate applications. NEMO system allows several ocean related components e.g. sea-ice, biochemistry, ocean dynamics, tracers etc to work either together or separately (MadecG., 2008). Recently a relatively newer version of NEMO (v_3.2) ocean model wasconfigured in NCMRWF high performance computing system at a coarser resolution.For initial test purposes, the global model resolution was kept at approximately 2o x 2o

latitude/longitude resolution to study the gross large-scale ocean circulation relatedfeatures from the model simulations. In this simulation 31 vertical layers were used inthe model. Out of these 20 layers were kept in the upper 500 meters of the ocean to takecare of the tropical air-sea interaction realistically. The initial model conditions wereprescribed from the climatological value. The model was integrated for 10 years with themonthly climatological data as forcing. The model-simulated parameters like surfacecurrents, SST, SSS, D20 isotherm, heat content in upper 300mts were examined for differentregions of the Indian Ocean. The simulations were compared against observedclimatological data. In a broad sense the monthly, seasonal and the annual cycle patternsfrom the Indian Ocean regions match reasonably well with the observations. Results fromthe simulations will be presented in the conference. In near future, at NCMRWF NEMOalong with the sea-ice model will be used at higher resolution for coupled modelingpurpose for a variety of weather and climate related research studies.


OSF-6

Time lagged Multiple Linear Regression Model Using KeyIndices of SST Fluctuations for Smaller Domains of Oceans

M. R. Anbarasan, S. Sundararajan*, B.K. Jena*, B. Vijay Bhaskar** and

S. Chandrasekaran**

Thiagarajar College, Madurai

*National Institute Ocean Technology, Chennai**Madurai Kamaraj University, Madurai

Sea surface temperature (SST) or its derivative SST anomaly (SSTA) is a property of oceanicclimate regime. The implied ecological significance SST variability had been widelyaccepted by scientific community. The correlation of SST variability to marine ecosystemresponses such as bleaching events in coral reefs is an example of the significance. Manycustomized versions of models such as GCM (General Circulation Model) are currentlyin use today to explain the variability and dynamics of land-ocean atmospheric physicalproperties such as SST, wind, sea level and so on across larger domains. Many alternatemodels such as Linear Inverse Model (LIM) and Ensemble Forecasts (or Monte Carlo)were also frequently used. Here, we have explored the potential use of key indices ofSST fluctuations in explaining the dynamics of SST in smaller domains. Patterns of SSTfluctuations in the oceans were available as key indices such as North Atlantic Oscillations(NAO), Pacific Decadal Oscillations (PDO), Indian index (IND), South Atlantic Oscillations(SATL), and Nino 3.4. We have chosen thermal sensitive reef ecosystems as smallerdomains in this study as a value addition. The reef domains included in this study wereBelize islands (BEL), Pulley reefs (PUL), Andros island (AND), Red sea reefs (RED),Maldives (MAL), Gulf of Mannar (GOM), Raja Ampat (RAJ), Great Barrier Reefs (GBR)and New Caledonia (NEW). As we have found statistically significant linear trends inmost of the smaller domains and the key indices, we have decided to use linear regressionmodeling as the tool to establish the relationships between the key indices and the SSTvariability in reef domains. Time lagged auto correlations and cross correlations by apositive ten years time lag among the key indices and reef domains were also seemed toexhibit statistically significant skill level for advance predictions. Since the trend and/orauto/cross correlations were insignificant, the key index Nino 3.4 and the reef RAJ wereexcluded from further analysis. So, by time-lagged multiple linear regression (MLR)analyses using XLSTAT Version 2011.1.01, we have factored in one or two key indices asindependent variables along with the time-lagged SST variable of the reef domain ofinterest.



By means of cross correlations and auto correlations at 95% confidence level, the reefs aregrouped into three types of indices: (1) Indian, (2) PDO/NAO, and (3) SATL. These threegroups also seemed to exhibit unique seasonal fluctuations. The model bias was validatedusing Mallow’s Cp coefficient which is one above the total number of explanatory variablesused to fit the model. The mean square of errors (MSE) was slightly above the perfectaccuracy and within the range of 0.100 to 0.324. The parameters were selected for modelfitting using adjusted R squared method, which revealed high predictability of the models.The adjusted R squared values were within the range of 0.764 to 0.952. Further, forwardforecasting were performed for ten years using the best fit models and SST anomalieswere derived using 1971-’00 climatology. The back-casting and forecasting results wereanalyzed and the patterns were compared.

Key words: Multiple Linear Regression - SST fluctuations – Oscillation indices – Coralreefs

OSF-7

Wave forecast from wind parameters using GeneticAlgorithm: A case study for the Bay of Bengal

A D Rao, Mourani Sinha and Sujit Basu*

Indian Institute of Technology Delhi, * Space Applications Centre, Ahmedabad

Basin scale prediction of ocean surface waves has major applications in variousoceanographic fields. Generally such predictions are carried out using numerical modelsinvolving large computational resources. This work reports a new alternative techniquefor the prediction of significant wave height (SWH) field in the Bay of Bengal (BOB) regionusing a combination of empirical orthogonal function (EOF) analysis and genetic algorithm(GA). To begin with the WAM-4C model is integrated using NCEP blended winds from2000 to 2008 (nine years) for the Indian Ocean covering 30ÚE to 120ÚE and 70ÚS to 30ÚN.The model computes daily SWH, wind speed (WS) and wind direction (WD) at six hourlyintervals. In the present study the data is analyzed only for the BOB region covering78ÚE to 103ÚE and 5ÚN to 25ÚN. Experiments are conducted using EOF and GA topredict SWH field using WS field, cosine of WD field (COSTHETA) and sine of WD field(SINTHETA). Initially the EOF analysis is performed separately on model generated SWHfield, WS field, COSTHETA field and SINTHETA field for 8 years (2000-07). This is todecompose the space-time distributed data into spatial modes ranked by their temporalvariances. Then we apply multivariate GA to the time series of the PC1 of the above fourvariables with lead times of 6, 12, 18 and 24 hours. We obtain the corresponding analyticalforecast equations which are linear relations connecting SWH, WS, COSTHETA and


SINTHETA. The data used for training the algorithm cover the period from 1st January2000 to 31st December 2007 consisting of 11680 points. Independent data used for validatingthe algorithm covers the period from 1st January 2008 till 31st December 2008 consisting of1460 points. For the independent data set we compute the PCs by taking scalar productof the corresponding data and EOFs of the training set. Then we use these actual PCs andthe analytical forecast equation to obtain the genetically forecasted PCs. We thenreconstruct the SWH of the independent set using the EOFs of the training set and thegenetically forecasted PCs separately for 06, 12, 18 and 24 hours ahead. We calculatespatially distributed root mean square error between the actual and reconstructed SWHfor all the lead times separately. Finally for any particular day, we compare modelforecasted and GA forecasted SWH of 06, 12, 18 and 24 hours ahead. The method has theadvantage that it can be used in the absence of any numerical wave model, since onlypast values of analyzed wind fields are required to predict SWH fields. The quality offorecast is evaluated in terms of root mean square error and found to be quite encouraging.

OSF-8

Simulations of tropical cyclone generated storm surges overthe North Indian Ocean using advanced coastal

hydrodynamic model

Maria Antonita. T, Remya P.G and Rajkumar

Space Applications Centre, Ahmedabad

The estimation of tropical-cyclone-generated surges in the coastal region is of criticalimportance to the timely evacuation of coastal residents, and the assessment of damageto coastal property. Numerical modeling has become an essential tool for assessing thehydrodynamics of coastal waters and for the study of the complex coastal systems whichaids in predicting storm surges and coastal inundations. In the present study, stormsurge hindcast experiments were performed along the Indian coastal region usingADCIRC (ADvanced Multi-Dimensional CIRCulation Model for Shelves, Coasts andEstuaries), which is a depth integrated, finite element hydrodynamic circulation model.The hindcast simulations were conducted for the tropical cyclones occurred in bothBay of Bengal (BoB) and Arabian sea (AS). The model was forced with both atmosphericmodel and scatterometer derived winds along with tidal forcing. The results of thesimulations performed i.e water elevation were validated with altimeter measured seasurface heights.



OSF-9

Ocean Surface Forcing from AGCM:Medium Range Systematic Errors for Monsoons

D. K. Mahapatra, A. K. Mitra, E. N. Rajagopal, Imran Ali and

L. Harendu Prakash

National Centre for Medium Range Weather Forecasting (NCMRWF), Noida

Surface forcing at air-sea interface plays an important role in driving the ocean circulationand distributing the water properties. In coupled systems, it plays an important role bycontributing towards various feed-back processes, which modulates the processes in theatmosphere-ocean system. In numerical modeling, these forcing are usually taken froman atmosphere general circulation model (AGCM) or its analysis (assimilation system). Itis therefore necessary to assess the representative ness and errors associated with thesesurface forcing parameters from the AGCM. Errors in first few days (medium range) arethe most crucial, which dictates the subsequent errors in monthly, seasonal and climatescales. It is important to document and then diagnose these errors for further modeldevelopment. In this study, an effort is made to quantify the systematic errors of surfaceforcing such as wind; sensible/latent heat fluxes; long/short wave radiations; rainfall andprecipitable water for the North Indian Ocean region covering 30oS to 30oN and 30oE to120oE during summer and winter monsoon of 2008-09 from NCMRWF T254L64 medium-range AGCM based weather forecasting system. The systematic errors are calculated withrespect to model’s own analysis. For rainfall the daily observed TRMM data were used tocompute model errors. From the errors it is found that the magnitudes are significant forthe tropical region especially zones pertaining to coastal regions. The systematic errorsgenerally increase with the forecast length. Contrasting error patterns are noticed forsummer and winter monsoon periods. Results indicating these systematic errors will bepresented in the conference.


OSF-10

Assimilation of significant wave height from EnviSATin coastal wave model using optimum interpolation

at variable wave height ranges

Suchandra A. Bhowmick, Raj Kumar and Sutapa Chaudhuri*

Space Applications Centre, Ahmedabad, *University of Calcutta.

Ocean observations from the space based platform are extremely crucial for monitoringand prediction of ocean surface. Nadir looking, microwave radar altimeters are mostcommonly used for this purpose. Assimilation of the altimeter data in the ocean modelsare the frontline research areas related to improvement of the ocean state forecasts. Inthis study significant wave height (SWH) from EnviSAT radar altimeter data has beenassimilated in the coastal ocean wave model SWAN (Simulating WAve Near-shore). Theoptimum interpolation (OI) technique has been used for this purpose. A detailed validationof the model and the EnviSAT observations has been carried out prior to the assimilationfor the determination of the error covariance matrix of prediction and observation. Thevalidation of the EnviSAT data and the model is done using the in-situ buoy observationsand Jason-1 altimeter data.

The validation exercise revels that at various ranges of SWH the error covariance changessignificantly for both the model and the altimeter measurements. The results shows thatthe assimilation of EnviSAT data at various ranges of SWH, using optimum interpolationscheme in SWAN model improves the prediction by 15 -20 % and there is reduction in theRMSE of SWH by 0.2 m. Multi-mission altimetric data assimilation using the sametechnique can improve the model prediction significantly.

OSF-11

Development of an automated Coupled Atmosphere-Ocean Modeling System and its Application for the

Kalpakkam Region

SubbaReddy Bonthu, Kaushik Sasmal, Hari.V.Warrior, Prageesh,. A. G

Indian Institute of Technology, Kharagpur, India.

The present study reports on the development of an automated atmosphere-oceancoupling system to enhance the understanding of oceanic processes. The coupled systemhas the capability to simulate features such as ocean surface circulation, sea-surface



temperature (SST) in a real-time mode. To accomplish this task, two state-of-art modelsviz; Weather Research & Forecast (WRF) Model developed at NCAR (National Centre forAtmospheric Research), USA and POM (Princeton Ocean Model) developed by thePrinceton University, USA has been used. The model WRF and POM simulates theatmospheric and oceanic parameters respectively. These two state-of-art models are runin a real-time mode with exchange of physical parameterizations achieved through thecoupling mechanism. The Flux coupling tool kit (FCTK) acts as an interface between thesetwo models. Initially, the atmospheric model (WRF) is run utilizing FNL data (providedas initial and boundary condition) where the output produced from WRF is required forthe subsequent POM run. The development of FCTK takes into account the estimation ofmomentum and heat fluxes from WRF, which is then provided as an external forcingparameter to POM in addition to climatology surface winds and the three dimensionaltemperature and salinity fields. In case with POM, the surface winds are obtained fromScatterometer measurements whereas the temperature and salinity fields at different levelsare obtained from the World Ocean Atlas (WOA, 2009). Based on several syntheticexperiments conducted and further establishing the robustness of FCTK, the developedflux coupler was applied for the Kalpakkam region located in the East Coast of India(about 70 Km south of Chennai) in the Tamil Nadu State. The location of Kalpakkam waschosen to study the dispersion characteristics of reactor plume outfall into the coastalwaters of Bay of Bengal. Two different experiments were conducted for this study region(Kalpakkam coast) by forcing POM, firstly through momentum flux alone and secondlywith the combination of momentum and heat flux through FCTK. It is expected that thesecond combination (combination of momentum and heat flux) should produce realisticsimulations of SST and surface circulation, rather than using only the momentum flux.The trajectory of the plume and variability of SST in the immediate vicinity of outfalllocation show a good correlation with the SST measurements. Based on model runs, itcould be advocated that inclusion of momentum and heat flux into POM through FCTKhas the advantages to study reactor plume dispersion characteristics in a real-time mode.

OSF-12

Validation of Eddy Viscosity Model in the Laboratory

Subhendu Maity and Hari V. Warrior

Indian Institute of Technology Kharagpur

In this study an attempt has been made to experimentally validate a new eddy viscosityformulation. The new formulation is based on anisotropy unlike the two equation modelswhich are very widely used but use a stability function approach which involves


determination of complex form of stability functions. The new model is validated withexperiments. The experiments are carried out in a recirculating water channel using anAcoustic Doppler Velocimeter(ADV) from Nortek AS, Norway one of the pioneers inmaking water velocity instruments. The instrument gives precisely the three velocitycomponents in the laboratory at high sampling rate. The readings are taken in the turbulentflow regime created by placing a grid in a flow. The velocities obtained are then processedinside an associated post processor from Nortek, to give a measure of the turbulent stresses.These turbulent stresses help us to calculate the eddy viscosity using our formulation.The eddy viscosity calculated are then validated using the k ε− model first developedby Launder which had undergone successive modifications since then. The stabilityconstant used in calculating eddy viscosity from k ε− model is taken as same as the oneused widely for studying turbulent flow patterns in industrial flows. From the experimentscarried out in the laboratory we found out that the eddy viscosity values we obtain are ofthe order 10-3 which are in tune with the values obtained from the two equation modelsviz. the k ε− model.

OSF-13

Indian Ocean Response to Windforcing using LCS Model

M. Surendar

Anna University, Chennai

Monsoons dominate the climate of the Indian Ocean and their neighbouring landmasses.Winds over the Indian Ocean blow from the Southwest during May-September andNortheast during November-February and drive a circulation that reverses its directioncompletely, which are dynamically important difference from the other tropical oceans.These monsoonal winds generate large seasonal variations in ocean currents, many ofwhich display annual and semi-annual reversals.

The equatorial Indian Ocean, however, experiences a somewhat different seasonal windforcing and hence has a different response than the other equatorial oceans. These windforcing induced some disturbances on equatorial Indian Ocean, So due to Ekmen pumpingKelvin waves propagate towards east coast along the equator and Rossby waves propagatetowards west coast along the north and south of equator. Kelvin waves after hitting theeast coast splitted into north and south direction as a coastal trapped Kelvin waves. Thesecoastal trapped Kelvin waves radiated Rossby waves towards west coast while movingalong the south and north coast. According to the periodicity of input wind forcing thecritical latitude of Rossby waves radiated by Kelvin waves varied. These large scale waves



propagate over the entire Indian Ocean coast, and make influence to local currentscombined with local wind forcing.

So understanding of local currents is not only depends on local wind forcing, whichdepends on remote forcing also. In this paper the brief study have been made forunderstanding the propagation of Kelvin waves and Rossby waves by various wind forcingand basin structure of Indian Ocean using LCS model. Various periodicity (50, 90&120)and steady input wind forcing in both zonal and meridional directions given as an inputof Indian Ocean realistic basin, the behaviour of Kelvin and Rossby waves observed. Sameexperiments have made for both indian-srilanka palk opened and closed realistic basins,and the variations observed. QuikSCAT and ASCAT winds (daily averaged winds)validated using RAMA buoys data. The variation between QuikSCAT and ASCAT windswere observed, and how this variation impact the dynamics of Indian Ocean also observed.Finally observed the propagation of these waves during the cyclonic period.

These experiments clearly shown that the critical latitude of Rossby Waves radiated byKelvin Waves has depended on input forcing periodicity. If periodicity high means criticallatitude also high. According to periodicity of input forcing upwelling and downwellingKelvin waves and Rossby waves generate and propagated.50, 90 and 120 day periodicityof input forcing excited the resonance periodicity. Finally observed the propagation ofthese waves during the cyclonic period.

OSF-14

Doubling of Tsunami Wave while at the Sea Shore:an Analytical Study

Ramkrishna Datta

Regional Meteorological Centre, Kolkata

Simple harmonic waves induced by Tsunami have been analyzed analytically. The velocityof propagation of waves depends upon the wave lengths. So the waves of nearly equalwave lengths can be considered as a group. This group of waves s will propagate withnearly equal velocity which is known as group velocity. On considering two consecutivesimple harmonic waves of same amplitude, we can find two equations describing simpleharmonic motions having slightly different wave lengths and time periods.The combination of these two said SHM’s we can find another resultant SHM with differentamplitude than of the previous two SHM’s. This new SHM has a slight variation in wavelength and time period than that of that of the said two SHMs. Then using the perturbationtechnique on this resultant equation of SHM we, can find a new wave velocity


(group velocity) in differential notation of wave velocity. This differential notation ofwave velocity has been eliminated from the relation between the wave velocity on thesurface of water and the depth of the sea. Then we get a relation of group velocity withdepth and wave velocity of the sea. The application of boundary conditions on depth ofdeep sea and that of the sea shore, we can find the group velocity at each regionrespectively. It is seen from the analysis that the group velocity at the sea shore is asmuch as double that of at the deep sea. Several recent cases of Tsunamis have been studiedand it is found that the results depicted the same implementation that established byanalytical study.

Keywords: Tsunami; Storm surge; Group Velocity; SHM; Hypo Centre; perturbationtechnique.

OSF-15

An implementation of Optimal Interpolation for waveheight analysis over Indian waters

N. Sasikala and S.A. Sannasiraj

Indian Institute of Technology Madras, Chennai

In an operational environment, the need for high quality sea state data is constantlyincreasing. The significant wave heights in an area of increased interest, the Indian Watersare analysed based on buoy data and corresponding forecasts obtained from numericalWAve prediction Model (WAM). Until recently, wave observations were scarce in mostparts of the world, so wave forecasting relied mostly on wave models forced by windfield from meteorological models. However they do suffer by its own inaccuracies due totheir approximations and erroneous control variables. This provides a space for dataassimilation schemes to stem where the available observations are introduced into themodeling procedures to have better predictions. In this study a widely used wave dataassimilation technique called Optimal Interpolation scheme has been used. The essenceof this methodology lies in the correction of the bias between wave model direct forecastsand buoy measurements. An error covariance structure has been formulated between thebuoy observation at a discrete station and the numerical model prediction over the entiredomain of interest. This is formulated to distribute the information inserted at one pointover neighbouring points statically in a sequential mode, assuming that there exists acorrelation between model predicted and buoy observed wave height. The differences tothe conventional OI algorithm are filtering the negative correlations from the covariancestructure to be consistent with the model physics and to accommodate the correctionsfrom another observation station to avoid over prediction at any grid stations.



The updated OI scheme has been implemented in Arabian Sea. The buoy data from DS1,DS2 and SW3 form the observation and validation stations. The updates over neighboringstations are discussed and the success of the OI scheme is highlighted. As expected, atthe observation station, the analysed wave height has a good concurrence. At validationstations (DS2 and SW3), the assimilation proves an improved wave forecasts.

Keywords: WAM, Data assimilation, Optimal interpolation, Error covariance matrix

OSF-16

Wave Hindcasting using Artificial Neural Network withvarying input Parameter

J. Vimala and G. Latha


The prediction of significant wave heights (Hs) is of immense importance in ocean andcoastal engineering applications. The aim of this study is to predict significant wave heightvalues at buoy locations with the lead time of 3,6,12 and 24 hours using past observationsof wind and wave parameters applying Artificial Neural Network. Although there existsa number of wave height estimation models, they do not consider all causative factorswithout any approximation and consequently their results are general approximation ofthe overall dynamic behaviour. Since soft computing techniques are totally data driven,based on the duration of the data availability they can be used for prediction. In theNational data buoy program of National institute of Ocean Technology, not all the buoyshave wind sensors and wave sensors and so it is attempted to apply neural networkalgorithms for prediction of wave heights using wind speed only as the input and thenusing only wave height as the input. The measurements made by the data buoy at DS3location in Arabian sea (12p 11’21"N and 90p 43’33"E) are considered, for the period2003 - 2004. Out of this, the data of period Jan 2003-Dec 2003 was used for training andthe data for the period July 2004- Nov 2004 is used for testing. MATLAB coding has beenmade for implementing ANN. In all the cases, TRAINLM was adopted as network trainingfunction. It is a network training function that updates weight and bias values accordingto Levenberg-Marquardt optimization. The transfer function used was logarithmicsigmoid, uniformly for first hidden and output nodes and purelin transfer function usedfor second hidden and output nodes. The performance of the models in significant waveheight forecasting is evaluated using statistical measures, namely Root Mean Square Error(RMSE), Mean Absolute Error (MAE), and Correlation Coefficient (CC). The performanceof ANN for varying inputs have been analysed and the results are discussed.


OSF-17

Altimetry and drifter data assimilation in anIndian Ocean circulation model

Manisha Santoki, K. N. Joshipura, Smitha Ratheesh*,

Rashmi Sharma* and Sujit Basu*

Sardar Patel University, Vallabh Vidyanagar 388 120* Space Applications Centre, Ahmedabad 380 015

In the present work, we have assimilated two different types of surface data in a sigmacoordinate Indian Ocean circulation model. The first data are of Lagrangian type and arethe drifter derived currents. The second type is satellite altimeter derived sea level anomaly(SLA). The altimeter derived SLA has been assimilated sequentially using statistical—interpolation scheme, while currents from the drifter have been assimilated by nudgingapproach, in the spirit of an earlier study of similar nature conducted in the Gulf of Mexico(Lin et al., 2007). Thus the present study can be considered as a logical extension of thestudy by Ratheesh et al. (2011) in which only satellite altimetry data were assimilated.Several experiments have been conducted with and without altimetry and/or drifter dataassimilation. For the purpose of comparison a forecast run (without assimilation of anydata) has also been conducted. Impact of the assimilation has been quantified bycomparing the model simulated variables like sea level and surface current againstindependent satellite and in situ observations. The standalone assimilations (either ofdrifter data or of altimetry data) show that the assimilations lead to an overallimprovement in the quality of simulation. In the case of drifter assimilation there isdeterioration in correlation for the sea level anomaly, which may be due to the fact thatthe model is attempting to simulate small-scale eddies not present in altimeterobservations. As far as surface current speed is concerned, we conjecture that because ofthe paucity of the number of deployed drifters, the improvement is not very high and thesituation may improve if more drifters are deployed. The standalone assimilation of SLAshows that there is largely positive impact. It is thus interesting to see whether thecombined assimilation can further strengthen the hindcast capability of the model byenhancing the correlation between the simulated and observed variables and by reducingthe associated root mean square errors.



OSF-18

Tsunami Inundation Modelling and Mapping along MarinaBeach, Chennai Using Cartosat-1 Data

R. S. Kankara, S. Chenthamil Selvan*, Tune Usha and

V. Ram Mohan*

Integrated Coastal and Marine area Management Project Directorate, Chennai

*University of Madras, Chennai – 600 025, India.

On 26th of December 2004 at 00:58:53, universal time (U.T.) an earthquake of surfacewave magnitude (Mw) 9.0 occurred off the west coast of northern Sumatra. Thedocumented death toll exceed-ed 283,000, with the heaviest loss along the west coast ofSumatra. Approximately 160 people died due to tsunami wave along the marina beach.In this paper, tsunami inundation modeling using was carried out using Cartosat dataalong marina beach. Marina beach, which is about 6 km stretch, is taken as the studyarea. CARTOSAT-1 is a state-of-the-art remote sensing satellite built by ISRO (IndianSpace Research Organization).The satellite was launched by the PSLV on May 5, 2005from the newly built second launch pad at Sriharikota, and is the eleventh satellite to bebuilt in the Indian Remote Sensing (IRS) satellite series. In order to accurately predict theextent of inundation and run-up in the coastal areas, high precision topography data isrequired. Topographic data are, thus, a major input to a tsunami model for computingextent of inundation. The movement of tsunami wave on land is governed by thetopography of that area. From Cartosat-1, Digital terrain model (DEM) can be extractedat 10m grid spacing. The numerical model “TUNAMI N2” used for this study is a nestedgrid model. Four grids, namely, A (2502m), B (834m), C (278m) in Linear mode and D(92m) in Non-linear mode are nested to form an inundation grid. Elevation datasets fromCARTOSAT-1 and field measurement collected using Real time Kinematic GPS (RTK-GPS) were compared for these areas. In comparison, it was observed that in most pointlocations Cartosat data was much closer to the field collected RTKGPS data. RTKGPSfield data has instrumental accuracy of less than 2cm. Based on the above comparison, itcan be concluded that CARTOSAT, data points have an accuracy of +/-1.5 m with theRTKGPS. Extend of tsunami waves along the marina beach are collected from records forvalidating the result. The maximum inundation limit was 700 m from shoreline and therun-up of about 2-3m is observed in the area. Tsunami modeling was carried out usingCartosat and the inundation map was prepared at 1:1000 scales, which was very usefulfor coastal zone management.


OSF-19

Sensitivity Study of Near-shore Wave induced Setup during anExtreme Event in the Bay of Bengal

Prasad K. Bhaskaran and A.G. Prajeesh


Coastal flooding due to an abnormal increase in near-shore water level has profoundimplications in disaster preparedness and its mitigation. During extreme events an increasein water level is expected which can be due to cumulative effects arising from reduced sea-level pressure, storm surge, tidal effects and wave induced set-up. The present study dealson numerical investigation of the wave induced setup based on various sensitivity experiments,and application to a category-4 cyclone ‘NARGIS’ which developed in the central Bay ofBengal during April, 2008. Wave setup is an increase of water level in the surf zone arisingdue to the transfer of wave momentum to the water column during wave breaking process.During this process the wave energy is dissipated but not the wave momentum, which isthereby transferred to water column resulting in a slope of water surface to balance the onshorecomponent of momentum flux. Firstly, the sensitivity experiments were performed for anarbitrary region having spatial dimensions of 5 Km ´ 5 Km with an open sea-ward boundary.Five different beach slopes viz; 1:80, 1:60, 1:40, 1:20 and 1:10 were assumed in this studydomain, and for each of these slopes varying grid resolutions viz; 25 m, 50 m, 100 m, 250 mand 500 m were chosen for this numerical experiment. The wind speed was assumed as 20ms-1 (taken at 10 m above water surface) blowing from offshore towards the coast. Forcingalong the open boundary was accounted from JONSWAP spectrum corresponding tosignificant wave height of 9 m with a peak period of 12 s. Results from these experimentsreveal that for gentle beach slope there is very marginal difference in significant wave heightirrespective of model resolutions, unlike the case for a steep slope. Also the wave setup wasfound higher for a steep beach slope with fine grid resolution as compared to the coarseresolution grid. This attributes the fact that model resolution is not sensitive in estimation ofwave setup for gentle sloping bottoms. Scaling down the grid resolution from 500 m to 25 mleads to wave setup which is about one order higher. In case of steep slope (1:10) computedwave setup with 500 m resolution is lower by 10% as that estimated with 25 m resolution.Based on results from these sensitivity experiments, wave setup calculations were performednear vicinity of Kalpakkam coast located in Tamil Nadu for the NARGIS cyclone event. Threelocations were identified in the coastal belt having different beach slopes which being 1:80,1:60 and 1:20. The nearest location of NARGIS from mainland was almost about 500 km awayfrom open boundary of the study domain. The maximum computed significant wave heightfrom SWAN model was 1.97 m with mean periods of 8.5 s. The computed wave setup wasfound highest for the steep slope (1:20) which being 0.3 m. This study advocates that wavesetup is an important parameter which essentially needs to be included in an operationalstorm surge forecasting system.



ABSTRACTS

THEME-8 OCEAN DYNAMICS


OD-1

Barrier Layer Formation in the Bay of Bengal as observed byOmni Buoys during Northeast Monsoon

Simi Mathew, G. Latha and R. Venkatesan


The freshening of surface layers of the Bay of Bengal (BoB) with the river dischargesduring southwest monsoon (SWM) and its course through the east coast of India with theEast India Coastal Current (EICC) during northeast monsoon (NEM) plays a major rolein bringing low saline waters into the south. The salinity profiles at the OMNI (OceanMoored Network for Indian Monsoon) buoy location during NEM reveal a subsurfacemaximum in conjunction with the strong southwest currents. This favours the formationof strong barrier layer in the southern BoB during NEM. The presence of high salinewater mass in the subsurface level in central BoB during SWM period was explained bythe Arabian Sea high saline waters. But the presence of this subsurface high saline watereven during NEM period traces its origin to the northern BoB. The close examination ofsubsurface currents reveals close correlation between subsurface southwest currents andhigh saline waters. This is a proof for the fact that lowering of salinity in the northern BoBby river discharges is limited to the upper layer (0-50m) of water column.

The Arabian Sea and BoB even though lies in the same latitudinal belt due to high evaporationrate of Arabian Sea waters over BoB and high river discharges into the BoB it was foundthat Arabian Sea waters are high saline compared to BoB. The two OMNI buoys [BD13 andBD14] deployed in the southern BoB gave continuous data for salinity, temperature andcurrent up to subsurface levels during the NEM of 2010. The winds during NEM favour theformation of EICC along the east coast of India. The bifurcation of EICC to the east at thesouthern tip of Sri Lanka brings in low surface saline waters to the buoy location. The lowsaline waters are associated with strong north east currents and the geostrophic currentsduring this period obtained from sea surface height obtained from AVISO satellite clearlyshows this low saline water as a wing of EICC. There is not much study of the subsurfacesalinity distribution in the BoB during NEM period. The salinity profiles obtained fromboth the buoy locations shows the presence of subsurface high salinity associated withstrong southwest currents. This clearly shows the origin of these subsurface maximumsaline waters to the northern BoB. The river discharges can only affect the upper watercolumn 0-50m depth. The high saline waters are confined to 50-100m depth in the northernBoB. Earlier studies conducted during SWM period also shown the presence of high salinewaters in the south central BoB and since the currents were northeast during this periodthis high saline waters were originated from Arabian Sea high saline waters.



OD-2

Spatial and Temporal Variation of Heat Content in theUpper 70m layer of the Arabian Sea

Gopika. N and Sajeev. R

Cochin University of Science and Technology, Kochi – 22, Kerala, India

The upper ocean heat content is the most important parameter in view of ocean atmosphereinteraction processes. In this study the temporal and spatial variation of heat content inthe upper 70m layer of the Arabian Sea for a period of 1991 to 2008 have been attempted.Sea Surface Temperature (SST) and Net Heat Flux (NHF) are the two major factors thataffect the heat content of the ocean. In order to establish the various role played by thesetwo factors on the upper ocean heat content we have explained the spatial and temporalvariation of NHF and SST in the Arabian Sea. The investigation was carried out in threeselected basin-wide boxes in the Arabian Sea; Box1 (Western Arabian Sea-8oN-20oN &50oE-60oE); Box 2 (Central Arabian Sea-8oN-20oN &60oE-70o E) and Box 3 (Eastern Arabian Sea-8oN-20oN &70oE-80oE). The inter-annual variation of heat content, NHF and SST in thesethree boxes during pre-monsoon, summer monsoon and winter monsoon seasons havebeen analyzed. Vertical profiles of temperature from the assimilated model output ofSODA is used to calculate the upper ocean heat content and the NHF data was takenfrom OAFlux data sets. Eastern Arabian Sea experienced a large amount of heat contentand it decreased towards western region. Inter annual variation of heat content showedthat during the strong IOD and strong El-Nino years (1997-1998, 2002-2003 and 2006-2007) all the three regions exhibited maximum heat content. In the western and easternArabian Sea, maximum heat content was observed during the pre-monsoon season andminimum heat content was observed during the summer monsoon season. But centralArabian Sea experienced maximum heat content during the summer monsoon seasonand minimum heat content during the winter monsoon season. From the analysis of SSTand NHF we conclude that in the western Arabian Sea, SST is the main factor that affectsthe heat content but in the eastern and central Arabian Sea both SST and net surface heatflux played a major role in influencing the heat content.


OD-3

Influence of Indian Ocean Dipole(IOD) onNortheast Monsoon

K.N.Navaneeth and M.R.Ramesh Kumar

Physical Oceanography Division, NIO, Donapaula,Goa-403004.

e-mail: [email protected]

Most parts of the Indian subcontinent receives over 75-90% of mean annual rainfall duringSouth-West Monsoon.The Southeast peninsular India which falls under the rainshadowregion during Summer Monsoon due to the presence of Western Ghats receives a goodamount of rainfall during Northeast Monsoon.The large scale South-West Monsoonassociated with well developed Synoptic features has been well studied whereas NortheastMonsoon over Southern peninsular India receives less attention.This study focusses onNorth East Monsoon Rainfall[NEMR] variability for a 48 year period and its relationshipwith Air-sea fluxes and SST,using Objectively Analysed flux data[OA-FLUX].Air-seafluxes like Latent heat,sensible heat,Evaporation,Wind and SST over the entire IndianOcean has been correlated with NEMR variability.It has been observed that SST in theEastern Equatorial Indian Ocean[0-10S,90E-110E] shows a positive correlation[0.4-0.5] inthe months of October and November.This region falls under the Eastern mode of IndianOcean Dipole[IOD].Hence the influence of IOD on Northeast monsoon is studied.Thenortheast monsoon and IOD are directly linked,suggesting that positive phase of IODenhances Northeast monsoon while the negative phase suppresses the Northeastmonsoon.The influence of IOD on Northeast monsoon is studied using National Centersfor Environmental Prediction-National Center for Atmospheric Research reanalysisdata(NCEP-NCAR).The wind pattern associated with the positive phase suggests atransfer of moisture from eastern Indian Ocean towards southern peninsularIndia.However the wind pattern associated with the negative phase of the mode suggestsmoisture transport away from the southern parts of India.Thus positive phase of the modesupports the transport of moisture towards India enhancing rainfall activity and negativephase inhibits the transport of moisture towards India suppressing rainfall activity.Thisclearly demonstrates the coupled Ocean-Atmosphere interaction in the tropical IndianOcean.

Key words: Northeast Monsoon,Air-sea fluxes,NEMR,Indian Ocean, IOD, NCEP-NCAR



OD-4

Influence of IOD events on sea surface height variabilityand circulation characteristics along the

South - West Coast of India

Phiros Shah and Sajeev R.

Cochin University of Science and Technology, Kochi-22, Kerala, India.

Sea surface height variability over the south-west coast of India were studied for a periodof eight years from 1993-2000 using all the available satellite measurements. The periodincludes two significant negative and positive IOD years. The study mainly focused onthe influence of remote forcings on the downwelling phenomenon and its temporalvariability. It was observed that during the positive IOD years the significance ofdownwelling Kelvin waves were absent along this coast. But normal and negative IODyears showed well defined patterns of coastally confined wave characteristics. Duringthe negative IOD years there are significant changes happened in winter season in termsof coastally trapped wave propagation, when compared to the positive IOD years. In themonth of October of the negative IOD years 1996 and 1998, Sea Surface Height Anomaly(SSHA) all over the South Eastern Arabian Sea (SEAS) is lower as compared to positiveIOD years. But in December there was a rapid increase in SSHA during negative IODyears along the coastal region. Compared to the normal and negative IOD years, strengthof the coastal currents seems to be diminished along the coast in the positive IOD years.This highlights that the strength of pole ward coastal currents are enhanced by thepropagation of downwelling Kelvin waves.

OD-5

Water Mass Characteristics of the Andaman Sea

Sudip Jana and Arun Chakraborty

Indian Institute of Technology, Kharagpur, Kharagpur - 721302, INDIA

The Andaman Sea (AS), a very less studied area of the Indian Ocean is located along thesoutheastern side of the Bay of Bengal (BOB) and bounded by the Malay Peninsula in theeast, Irrawaddy Delta in Burma in the north, Sumatra in the south and the Andaman andNicobar islands in the west. After few meters of depth, it is surrounded by land from allthe sides and it behaves like trench. The rapid change in depth gives a special effect in itsbathymetry. The northern and the eastern parts are shallow whereas the western side iswith steep slope and the depth suddenly changes to greater than 4000 meter in the centre


of the Sea. Andaman and Nicobar islands behaves like a wall separating the AS from theremaining part of the BOB. The AS exchanges its water mass with the BOB through thethree main channels: Preparis Channel, the Ten Degree Channel and the Great Channel.In the southern side it is connected to the Malacca Strait, which allows the exchange ofthe subsurface water mass with the Indonesian Seas. This special effect of the bathymetrymakes its deeper water mass isolated from the remaining part of the Bay of Bengal. Thisstudy presents a brief analysis of the water mass characteristics of the Andaman Sea andits seasonal variation. Historical in-situ Conductivity-Temperature-Depth (CTD) data,Profiling Float (PFL) data and Ocean Station Data (OSD) from the World Ocean Database(WOD09) have been used in this study. Analysis has been done to identify the pattern ofwater masses in the Sea. The physical properties we have analyzed are the temperatureand the salinity over the years. Comparison has been done between the water massesfrom the AS and its surrounding regions (i.e. the western side of the Andaman and NicobarIslands). The results indicate the existence of relatively warm and high saline water inthe deeper part of the sea and low saline water in the subsurface region in comparison tothe surroundings of the sea. The water mass of AS basin is greatly influenced by thetransport of monsoon currents and Malacca Starit throughflow.

OD-6

Seasonal cycles of heat budget components during thecontrasting years of 2004 and 2007

P.M.Muraleedharan, Keerthi, M.G., *Nisha, P.G.

National Institute of Oceangraphy, Goa 403004.*Indian Institute of Science, Bangalore-560 012

Sea Surface Temperature (SST) and Wind Speed (WS) data over the tropical Indian Oceanduring the contrasting years 2004 and 2007 were derived from the ascending anddescending passes of TRMM (Tropical Rainfall Measuring Mission) Microwave Imager(TMI) and humidity from SSMI brightness temperature data following Schlussel et al.(1995). The latent (LHF) and sensible heat (SHF) fluxes were computed from the aboveparameters using COARE 3.0 algorithm proposed by Fairall et al., (2003). The net oceanicheat gain was then calculated from the above parameters. Quality checked monthlyaveraged Argo profiles together with CTD profiles [World Ocean Data Center (WODC)and Indian National Oceanographic Data Center (INODC)] leaves less gaps to be filledwith interpolated (krigging) values to have sufficient temporal and spatial coverage overthe tropical Indian Ocean in 2004. The horizontally interpolated (variational analysisinterpolation technique) and gridded monthly data products were obtained for the year



2007 from the IPRC (International Pacific Research Center) web site (http://apdrc.soest.hawaii.edu/datadoc/argo_iprc.php). The zonally averaged oceanic heatcontent with in the mixed layer, heat storage, heat export and heat transport were thencomputed during both years to understand the inter annual variability. The area multipliedmonthly net oceanic heat flux, heat storage and heat transport were then integrated fromnorth to the equator to make the comparison easy and meaningful.

Anomolous solar heating and enhanced surface wind situation weakens the air-seacoupling process in 2007 whereas the relatively low SST and weak wind in 2004 generatedhigh LHF as a result of enhanced air-sea coupling. The seasonal cycles of both heat storageand heat export pattern indicated southward propagation during the monsoon monthsof 2004 and 2007 and are supported by the heat transport computations incorporatingboth geostrophic and ekman components. Heat depletion of the north Indian Ocean duringsummer months is much higher in 2004 compared to 2007. The enhanced meridionalheat transport of 2004 is responsible for such depletion. Similarly weak meridionaltransport may be responsible for the low heat depletion noticed in 2007.

The anomalous heating of the ocean makes the surface layer more stratified and slowdown the meridional overturning cell resulting in dampened meridional transport. Thesurface stratification, as in the case of the year 2007, retains the SST above the prescribedthreshold of 28 C thereby creating situation conducive for triggering atmosphericdisturbances. In the year 2007 there were about 26 low pressure systems developed inthe north Indian Ocean when compared to 12 such systems in 2004. This feed back fromthe ocean along with LaNina induced Walker circulation probably supported the enhancedrainfall over the subcontinent and marked 2007 as a normal monsoon year and the year2004 was declared as a draught year due to the subsidence caused by ElNino althoughthe evaporation was highest in 2004.

Key words: Meridional circulation, heat storage, heat transport, Indian Ocean, air seacoupling, Argo profiles.


OD-7

Sea breeze induced wind sea generation and growth in thecentral west coast of India during pre-monsoon season

V.M. Aboobacker, P. Vethamony, M. Seemanth

National Institute of Oceanography (CSIR), Goa

It was identified that the wind seas generated due to sea breeze superimpose with pre-existing swells off Goa during pre-monsoon season and creates complex sea states. Theassociated characteristics are increase in wave height and decrease in mean wave period.However, it is essential to understand the generation and growth of sea breeze inducedwind seas and their interaction with pre-existing swells, which is not yet fully understood.One of the limitations in studying the interaction is the lack of fine resolution winds,which could be applied as the input parameter in numerical wave modelling. Global windssuch as NCEP (National Centers for Environmental Prediction, USA) and ECMWF(European Centre for Medium-range Weather Forecasts) have limitations in its temporaland spatial resolutions as well as in representing the winds very close to the coast. In thepresent study, a mesoscale model, MM5 has been implemented to simulate winds off Goaduring pre-monsoon season which is capable of reproducing fine details of sea breezecharacteristics. These model winds are validated with winds measured using AutonomousWeather Station (AWS) on the Goa coast. Spatio-temporal variations in the wind velocitiesover the sea breeze dominated area have been traced. Waves measured off Goa clearlyshowed the presence of sea breeze induced wind seas, and the wind sea parameters havebeen separated from the wave spectra.

Numerical wave model has been set up to simulate wind seas off Goa during pre-monsoonseason utilising MM5 winds, and the wave model results have been validated withmeasured wind seas. The correlation coefficient, bias, r.m.s.error and scatter index betweenmeasured and modelled significant wave heights are 0.73, 0.03 m, 0.12 m and 0.26,respectively. This shows that MM5 winds reproduced the wind seas off Goa moreaccurately than previous efforts, in which NCEP winds were used as the input parameter.It has been found that the wind seas due to sea breeze are generated at an offshore areabetween 100 and 150 km away from the coast, and a gradual wind sea growth towardsthe coast is evident as the sea breeze intensifies.



OD-8

The role of Thermal inversions on Hydro-physical processesalong the coastal waters off Visakhapatnam, East coast of India

T. Sridevi, K.Maneesha and V.V.S.S. Sarma

National Institute of Oceanography, CSIR, Visakhapatnam – 530017, India

Thermal inversions are one of the important physical processes seen most commonly inthe Bay of Bengal. In this work, we focused on the formation of thermal inversions in thevery shallow coastal waters off Visakhapatnam, as this affects the coastal upwelling,nutrient input and therefore primary productivity. We have conducted monthly surveyin the coastal BOB, off Visakhapatnam, from 10m depth to 100m depth water columnfrom October 2007 to February 2010 to understand the effect of inversions on coastalprocesses and causative factors responsible for very shallow waters. We also addressedthe influence of remote forcing in the modulation of temperature inversions in this region.Based on the observed data we classified these inversions into two types - salinity driventhermal inversions and temperature driven thermal inversion. Due to weakening of EICCduring January, February the fresh water influence on surface decreases. The thermalinversion of 0.26°C to 1.2°C where observed during winter in the coastal BOB whenrelatively weak stratification compared to monsoon period was observed due to weakeningof EICC. During winter atmospheric temperature decreases by 5°C. During this periodinversions were observed up to 70-80m. The weak thermal inversion during summer wasassociated this strong stratification resulting in decrease of vertical mixing. Thereforeinversion during winter and summer caused atmospheric temperature and salinity byriver discharge respectively. The magnitude of inversions decreased towards offshoreand deepened from coast to offshore. It was observed that low nutrients and chlorophyll-a concentration where associated thermal inversions suggesting that inversion playssignificant role of marine ecosystem in the costal BOB.


OD-9

Variability of near-surface temperature fields onIntra-seasonal to inter-annual time scales in the

south eastern Arabian Sea (SEAS)

Nisha Kurian1, V.V.Gopalakrishna1, R.R.Rao2, S.Amritash3, Lix John3

and C.Revichandran3

1 National Institute of Oceanography, Dona Paula, Goa -403004, India2Andhra University, Visakhapatnam - 530003, India

3National Institute of Oceanography Regional Centre, Kochi-682018, India

South eastern Arabian Sea (SEAS) located in the northern Indian Ocean is an importantregion on many counts. For example, core of the Indian Ocean warm pool forms over thisregion whose strength determines the onset and northward extension of the Indiansummer monsoon season. SEAS is one of the most biologically productive regions of theworld oceans contributing to large fishery resources due to upwelling during Indiansummer monsoon season (SMS). During winter, advection of Bay of Bengal origin lowsalinity and low temperature waters in to SEAS significantly reduces the salinities overthis region and leads to the formation of barrier layer which ultimately supports formationtemperature inversions. It is believed that these temperature inversions enhances the SSTand helps strengthening the warm pool. Thus plays a key role in the regional climatesystem. However due to paucity of systematic short term (weekly to fortnightly)temperature/salinity measurements for longer periods following are not well known: theinterannual and intra-seasonal variability of (a) salinity and its contribution on theevolution of temperature inversions and its characteristics, (b) upwelling and (c) upperocean thermal structure.

Under the Ministry of Earth Sciences (MoES), Government of India supported long termobservational program, we have been collecting vertical temperature profiles by deployingexpendable Bathy Thermographs (XBTs) and water samples for the analysis of sea surfacesalinity (SSS). The data are collected since 2002 onwards at fortnightly time and 50kmspatial intervals in the SEAS using ships of opportunity. Utilizing the unique eight yearstemperature / salinity data and supporting with satellite measurements (surface winds,OLR, TMI SST, AVISO girded SSH) we tried to answer the above posed questions in thepresent study.



OD-10

Influence of mesoscale eddy on vertical mixing andspreading of water mass in the Arabian Sea

PA Maheswaran, Dominic Ricky Fernandez, J. Swain

Naval Physical and Oceanographic Laboratory, Cochin

Variability of surface circulation and water mass in southern Arabian Sea extending fromSomali coast to the west coast of India have been studied using data sets from multimissionAltimetry, Tropical Rain Measuring Mission (TRMM) satellite’s SST and hydrographictemperature and salinity. In winter, the cyclonic eddy off Somali coast prevents thewestward spreading of low saline waters brought by the North Equatorial Current,consequently this low saline waters re-circulate in the south-eastern Arabian Sea. Inorder to examine the influence of mesoscale eddy on the vertical mixing and spreading ofwatermass, potential vorticity and cyclonic eddy index were calculated. It was foundthat, characteristics of the Arabian Sea mini warm pool significantly depend on the wintertime mesoscale eddy index. Further, a quantitative study of mixing and subduction ofwater masses viz., Bay of Bengal, Arabian Sea, Somali and Equatorial surface waters werealso investigated for the west, central and eastern portions of study region.

Key words: Mesoscale eddy, watermass, Arabian Sea mini Warm pool, cyclonic eddy index,potential vorticity.

OD-11

Characteristics of Bay of Bengal Water mass in the SouthEastern Arabian Sea during 2001-2002

G Nageswara Rao, K Anil Kumar, PSV Jagadeesh and P Anand

Naval Physical and Oceanographic Laboratory, Kochi

The low saline Bay of Bengal water intrusion to the Arabian Sea along the west coast ofIndia during the north east monsoon is a well known fact. This paper examines thecharacteristics of this intruded Bay of Bengal water mass (BBW) during November 2001 –May 2002 by utilizing Simple Ocean Data Assimilation (SODA) model outputs (T, S andCurrents). During November 2001 the southward flowing East India Coastal Current(EICC) along with the Winter Monsoon Current (WMC) brings BBW to Arabian Seatraversing around Sri Lanka coast and feeds the poleward flowing West India CoastalCurrent (WICC). Even though EICC reversed its direction by January, the WMC alongwith the WICC transported the BBW further north. The maximum northward limit of the


BBW was 15.25°N during January-March which is peak phase of WICC. When the WICCreversed its direction by March the BBW started depleting and by May no trace of BBWwas seen in SEAS. Further, the thickness of the water mass were computed for the entirestudy region and also vertical integrated volume transport were computed along transects(77.5°E,8.25°N,10.25°N,12.75°N and 15.25°N) perpendicular to the coast. The thicknessof the water mass was found to vary from 10 to 50m during the entire study period. It wasshoaled during the November and March-April while it deepened during peak phase ofWICC (January-February). Maximum volume transport of 0.8 Sv towards west along77.5°E was observed during February. During all months total volume transport was seento be reducing towards the Northern transects.

OD-12

Air-sea interactions and upper ocean thermal structure variationsduring different epochs of MALA Cyclone over Bay of Bengal

Naresh Krishna Vissa, A.N.V. Satyanarayana, and B. Prasad Kumar


Tropical cyclones are one of the major natural hazards which inflict severe threat to humanlife and property having implications on socio-economic aspects in the affected regions.It is considered as the most intense case in air-sea interaction studies where energy fromthe warm ocean waters is supplied through surface heat flux. ARGO profiling floatsprovides valuable information of the ocean’s temperature and salinity structure evenduring the passage of cyclones. Temperature and salinity profiles for the present studywere obtained from eleven different ARGO floats for the period 14 April to 9 May 2006(±10 day’s window of MALA passage) in the study domain encompassing geographicalcoordinates bounded by latitude 5-20oN and longitude 85-95oE within the vicinity of MALA

cyclone track which was formed and dissipated during 24-26 April 2006 over Bay of Bengal.The passage of MALA cyclone also resulted in cooling the sea surface temperature (SST)by 4-5°C. The findings suggest that turbulent and diapycnal mixing are responsible forcooler SSTs. A significant variation of mixed layer depth (MLD) and barrier layer thickness(BLT) during the different phases of MALA is noticed. Deepening of MLD and weakeningBLT associated with a deeper 26° C isotherm level (D26) is observed after the MALA

passage. Tropical cyclone heat potential (TCHP) and depth averaged temperature (100

T )exhibit good degree of correlation for higher values. Turbulent air-sea fluxes are analyzedusing Objectively Analyzed air-sea Fluxes (OAFlux) daily products. During the maturestage of MALA higher fluxes of sensible and latent heat and enthalpy are observed in theright side of the track of this extreme event.

Keywords: Upper Ocean, mixed layer, TCHP, air-sea fluxes



OD-13

Implication of Empirical Orthogonal Function Analysis toObjectively Analyzed Ocean Temperature Data of

Bay of Bengal

Tarumay Ghoshal, Sudip Jana and Arun Chakraborty

Indian Institute of Technology Kharagpur, Kharagpur-721302, India

Empirical Orthogonal Function analysis is a very powerful statistical technique whichdecomposes multivariate dataset into some orthogonal basis functions, called modes whichinclude both temporal and spatial patterns. This method can reflect to some essentialsignal characteristics from the larger dataset. The objective of this study has been dividedinto two categories. First, to obtain the intrinsic and valuable informations from the oceantemperature data for the Bay of Bengal through empirical orthogonal functions. Second,to reconstruct the whole dataset from the dominant modes and comparison with theoriginal data to show the accuracy. It is well known that Bay of Bengal temperature isinfluenced by several factors like monsoon effect, enormous river discharges and dominantocean current systems. Due to lack of availability of proper in-situ data, it was quitedifficult task to interpret the proper variations of ocean temperature for a long time. Afterthe availability of ARGO floats data that task has become comparatively easier. In thepresent study we have used the climatological temperature data over the Bay of Bengalobtained from the assimilation of the recent ARGO observations into the 0.25° Levitusclimatology by objective analysis. Empirical orthogonal function analysis is accomplishedon this new dataset through singular value decomposition method. The method is donein two steps. First, the temporal mean is removed from the data set and then decompositionis done. Next, the process is repeated after removing the spatial mean from the originaldataset. The decomposition generated temporal and spatial modes for both the steps,and which are analyzed thoroughly. Taking five dominant modes, the whole dataset havebeen reconstructed. The accuracy of this computation is calculated through skill analysis.Temporal mode time series shows high correlation with the spatial mode patterns for thenear surface temperature. Specially, mode three reveals temperature variations almostaccording to Indian Ocean dipole index and ENSO index. This is also evident from spatialmode patterns. The seasonal dominance of high sea surface temperature near the Ganges-Mahanadi river discharge is very much proved from the spatial mode patterns. From thecomparison between original dataset and the reconstructed dataset, it is revealed thatempirical orthogonal function analysis not only extracts the small intrinsic signals, butalso acts like a smoothing technique which filters out the unwanted signals. Skill analysisreveals accuracy in the range of 98-99%.


OD-15

Effect of Sea ice melting on the mixed layer depth variationin the Indian Ocean Sector of the Southern Ocean

Pranab Deb, Mihir K. Dash and P. C. Pandey

Indian Institute of Technology Kharagpur, Kharagpur-721302

Melting of sea ice in different sectors of the Antarctic modifies the regional mixed layer propertiesof the ocean as well as has a remote effect. This study describes the effect of sea ice melting on thechanges in the mixed layer depth in the Indian Ocean sector of the Southern Ocean. Thetemperature and the salinity profiles from the World Ocean Database 2009 Geographically SortedData (WOD09) for the region 50oS-60oS and 60oE-90oE from 1978 to 2007 have been used to studythe mixed layer depth (MLD) characteristics of the region. The thermal mixed layer, densitymixed layer and the barrier layer were calculated from the individual profiles for the months ofJanuary and February. Then monthly averages were computed for January and February. Theaverage values were compared well with that of existing climatology. The passive microwaveradiometer derived sea ice extent data from National Snow and Ice Data Centre (NSIDC),Colorado, USA were used to compute the sea ice melting in different sectors of the Antarcticduring the month of December. It was found that the sea ice melting in the Indian Ocean regionhas a significance correlation with the barrier layer formation in the study region.

OD-14

Dynamics of intraseasonal thermocline variability in theTropical Indian Ocean during 2004

Bhasha M. Mankad, Rashmi Sharma, Sujit Basu and P. K. Pal

Space Applications Centre, Ahmedabad 380 015

For the tropical Indian Ocean, depth of the 20o C isotherm (D20) is a reasonable proxy for thethermocline depth. An ocean general circulation model (OGCM) is an important diagnostictool to study the upper ocean variability, including the variability of D20. In the present study,Modular Ocean Model, version 3.0 (MOM3.0) has been used to study the intraseasonalvariability of D20. Two runs of the model have been performed for the year 2004. In the firstrun , hereafter designated as Reference Run, the model is forced with daily fluxes from NCEPreanalysis and winds from QuikSCAT for the year 2004 (CNTL-R). In the second run, designatedas experimental run (EXP-R), weekly MSLA data are assimilated in the model, while retainingthe same forcings. The MSLA data are assimilated through the water property conservationscheme. The validation of the runs is done at few locations using data from RAMA buoys.

In order to study the dynamics of thermocline variability, spectral analysis of the time series ofD20 at few buoy locations were carried out. Dominant spectral peaks in the intraseasonal frequenciesare analysed in detail. Further runs of the model are performed after removing the intraseasonaloscillations and a diagnosis of the causes affecting variabilities at different time scales are analyzed.



ABSTRACTS

THEME-9 ATMOSPHERE & OCEANS-CLIMATE CHANGE


AOCC-1

Response of Aerosol Optical Depth (AOD) to the GeneralCycle of Global Climate in the Western and

Eastern Indian Ocean

Shalin Saleem, KV Sanilkumar, CA Babu* and CVK Prasada Rao

Naval Physical and Oceanographic Laboratory, Ministry of Defence, DRDO, Kochi-21*Department of Atmospheric Sciences, CUSAT, Foreshore Road, Kochi-16

The western and eastern Indian Ocean has been receiving attention for the last one decadein terms of the Indian Ocean Dipole (IOD). Positive, neutral and negative phases of theIOD are identified based on the Sea Surface Temperature (SST) in these regions. Theresponse of IOD is reflected in all the atmospheric parameters viz. atmospheric winds,pressure, humidity, amount of rainfall, air temperature etc. Therefore, real-timeinformation at closer spatial interval on any atmospheric parameters from these regionshas got significant importance in the field of climate studies. In this regard, ocean coloursensors of satellites give an atmospheric parameter Aerosol Optical Depth (AOD) at closerspatial interval of 360 m x 360 m. With a view to take the advantage of this high resolutiondata to understand the climate change, a study is undertaken utilising AOD data ofSeaWiFS (September 1997 – December 2010). Good response for AOD to the cycle of IODand El Nino in the western and eastern regions of the Indian Ocean especially during1997 and 2006 was noticed. One of the reasons for this response may be different sourcesof AOD during the occurrence of these atmospheric phenomena. In order to identify thesources of the aerosols in the study regions during different epochs of these climaticcycles, HYSPLIT model developed by the Aerosol Optical Laboratory, USA was used andtraced back the trajectory of aerosols at three atmospheric levels of 1000, 950 and 700 mbusing. The study revealed that the sources of aerosol supply in the study regions varyduring the periods of IOD / El Nino.

AOCC-2

Effects of Atmospheric Interferences onCoastal HF Radar Measurements

Rajnish Antala, Manu P John, and B. K. Jena

National Institute of Ocean Technology (NIOT), Chennai - 600100

Coastal High Frequency (HF) Radar signal is affected by atmospheric interference (windand cloud), sea state, ionospheric effect, and extra-terrestrial activities. Recent studies oneffect of HF Radar signal shows that effects of these parameters have major control on



the quality of data reception. In the present study the data quality of HF Radar signalalong Indian coast have analyzed and found the effect of ionosphere is dominant compareto other parameters.

Coastal HF Radars are operational along east and west coast of India including Andamanand Nicobar islands for ocean surface current measurement and high wave activities. Ituses seawater as its’ medium for transmission and reception of the Radar signal. Therecent data analyzed at all sites along Indian coast shows that the radial coverage of datadecreases from day to night. At Kalpakkam site the maximum range of 216.5km duringday time recedes to 70km at night, where as it recedes 140 to 120km at Machilipatanam,210 to 160km at Gopalpur(along east coast of India) and 180 to 80km at Jegri site(alongwest coast of India). However, the signal is also affected by various atmospheric andterrestrial activities. This study gives an overview of these effects along Indian coast.

AOCC-3

On the Relative Roles of Onset Vortex and Mini Warm Poolover the Arabian Sea on the Monsoon Onset over Kerala

M.R.Ramesh Kumar and Syam Sankar

National Institute of Oceanography, Goa - 403004

The inter-annual variability, in the formation of the mini warm pool (MWP, sea surfacetemperature > 300 C) over the Arabian Sea (AS), and its role in the formation of the monsoononset vortex (MOV), has been examined using the recently released high resolutionHamburg Ocean Atmosphere Parameters and fluxes from Satellite data (HOAPS 3), NCEP/NCAR Reanalysis circulation at 850 hPa, and the outgoing longwave radiation (OLR)dataset for the period 1988 to 2005. The present study examines the role of sea surfacetemperature, evaporation, wind speed and integrated columnar water vapour, the lowlevel jet at 850 hPa and OLR in the formation of the MWP, as well as MOV over the AS. Wefurther examine the role of various ocean atmosphere parameters over the AS during theonset vortex years, as well as during non-onset vortex years for better understandingtheir role in relation to MWP and MOV. The low level wind circulation at 850 hPa clearlyshowed that they were formed only in those years when the LLJ was conducive for itsformation. The study further explores the reasons for the presence or absence of MOVover AS. Even though an MWP was present over the AS one pentad prior to MOK, duringmost (13 out of the possible 18 years) of the study period, the MOV has formed onlyduring three years (1994, 1998 and 2001), indicating its insignificant role on MOK.


AOCC-4

Climate Change and its Impacts on Marine Fisheries

P. Nammalwar, S.Satheesh and R. Ramesh

Institute for Ocean Management, Anna University, Chennai – 600025

Global warming and the resulting climate change are among the most seriousenvironmental problems facing the world community. Climate change has the directimpact largely on the coastal marine environment and their living resources especiallyfisheries. These climate impacts alter the availability of living marine resources, affectsspecies biodiversity, productivity of the ocean and timing of seasonal biological events.Rising global temperature is expected to raise sea levels, change precipitation and otherlocal climate conditions. The seas around as dictate terms in deciding the climate andweather. They cover around 70% of the global surface and play a vital role in sustainingbiodiversity and fishery resources. India’s food and water security systems will be theworst victims of a rise in mean temperature. Building our defence against potential climatechange activated calamities through mainstreaming climate resilience in all developmentalprogrammes should be the priority task today. The ocean plays a vital role in India’seconomy by virtue of their resources, productive habitats and wide biodiversity. Thepresently emerging anthropogenic climate change has an impact on the performance ofthe global player ‘ocean’ as well as on the risks in coastal zones and their resources.

Climate changes predicted as a result of increases in green house gases are likely to impactcoastal aquaculture systems. Rising sea level inundate coastal aquaculture farm landsenhance saltwater intrusion make coastline retreat and force shift to salt tolerant activitieslike shrimp farming. Towards the end of 21st century, the projected sea level rise willaffect low lying coastal areas. This will damage many coastal ecosystems such asmangroves and salt marshes which are essential for maintaining many wild fish stock aswell as supplying seed to aquaculture. Climate change impacts on aquaculture have bothdirect (e.g. through physical and physiological processes) and indirect (e.g. throughvariation fish meal supplies and trade issues). The physical changes related to climatechange, i.e. in temperature, solar radiation, current and wave actions, sea level rise, waterstress, and the frequency of extreme events, will impact physiological, ecological andoperational (e.g. species and site selection, containment technologies etc.) processes.Positive impact of climate change on aquaculture includes food conversion efficienciesand growth rates of finfishes and shellfishes in warm waters. The present paper providesa review of potential impacts of climate change on marine fisheries.



AOCC-5

Impact of Rossby Wave on Variation ofIndian Summer Monsoon

Dhrubajyoti Samanta, M K Dash and P C Pandey

Indian Institute of Technology Kharagpur, Kharagpur, India – 721 302

Indian Summer Monsoon (ISM) is one of the important phenomena in the tropical calendar.Proper understanding of ISM (June to September) has profound importance to south Asianhydrological cycle. Indian subcontinent experiences anomalous southerlies in the deficitmonsoon year and northerlies during the excess monsoon year due to spatial phases ofRossby wave during these periods.

The present paper describe the behaviour of the Rossby wave during normal, excess anddrought years over the Indian Ocean in the wind and Outgoing Longwave Radiation(OLR) pattern. The monthly wind and the OLR anomalies have calculated by subtractingthe climatology from that of the monthly values. The climatologies have generatedconsidering only the normal ISM years. The wind pattern shows cyclonic vortex aroundnorth-east part of Indian Ocean during drought years like 2002 and 2009. OLR patternshows the occurrence of deep convective cloud in normal monsoon years between 70E to100E, whereas same is located between 90E to 120E during drought years. Shifting ofRossby wave pattern is observed along zonal direction in the OLR anomalies during 2002and 2009. Pressure-Longitude cross section of potential vorticity shows anomalousbreaking of Rossby waves in drought years between 50E and 70E. It affects the monsoonalconvection process and the rainfall.

ABSTRACTS

THEME-10 (A) MARINE ECOSYSTEMS


ME-1

Impact of Coastal Processes and Geomorphology on turtlenesting along Orissa coast, East coast of India

P.K. Mohanty1, S.K.Patra1, B. Seth1, U.K Pradhan1, B. Behera1, S. Barik1,

P.K. Kar1, S. Bramha2, P. Mishra3 and U.S.Panda3

Department of Marine Sciences, Berhampur University, Berhampur-760 007, Orissa1NIOT,Chennai, 2IGCAR,Kalpakam, 3ICMAM Project Directorate, NIOT Campus, Chennai-600100

Orissa has three mass nesting beaches, the rookery near Rushikulya river mouth, Deviriver mouth and Ekakulanasi near Dhamara. Olive Ridley Sea Turtles are nesting en masseat these rookeries that fluctuate from year to year. The objective of the present study is toassess the impact of coastal processes and the geomorphology of beaches on the nestingbehavior and its interannual variability.

The information on beach profile, areas and volume of sediment transport, shorelinechange, surf zone width, hydrographic conditions (salinity and TSS) and sediment grainsize of nesting beaches were collected near Rushikulya every month from June 2008 toDecember, 2010. Information on waves, currents and winds were collated for the specificperiods of mass nesting to understand what triggers it. Beach profiles indicated thatnarrow beach width due to erosion and higher beach slope led to decline in mass nesting.Continuous northward growth of the spit resulted in erosion immediately to the northand hence gradual shifting of the nesting beaches further north. The grain size analysisindicated that the nesting beaches have mean grain size of coarse to medium (0.5-1.4 phi)and are polymodal in distribution. Sediments are very well sorted in the foreshore andmidshore (<0.35 phi), moderate to poorly sorted in the backshore (0.5-2.0 phi). The resultssuggest that depositional environment from November to March; low tidal range(0.85m),low wave activity (0.5-1m), stable and flat beach, high saline water(32-33), low suspendedsolid concentration and high productivity provide a conducive environment for massnesting of Olive Ridley Sea Turtle. Analysis of wind direction and speed from 1994 to2009 for the periods of mass nesting indicates that almost 180o shift in the wind direction,increase in wind speed and the associated wave conditions, and onset of southerly windact as precursor for triggering the mass nesting on the particular day. Triggering of massnesting on 10th February, 2009 also satisfied the above wind conditions besides a shift inthe current direction from northerly to southerly and a drop in the current speed from0.4 m/s to 0.15 m/s.



ME-2

Bacterial Abundance in Godavari Estuary: Influence of RiverDischarge on Bacterial Metabolism

D.T. Manjary, V. R. Prasad, L. Gawade and V.V.S.S. Sarma

National Institute of Oceanography (CSIR), Visakhapatnam

Heterotrophic bacteria are important key components in any aquatic system and are themajor mineralisers of organic carbon and nutrients where the organic carbon can berecycled back into the food webs or accumulated into bacterial biomass. The source oforganic carbon to the estuary can be either from in situ primary production(Autochthonous) or from external terrestrial inputs (Allochthonous). Estuaries act asintermediates in exporting the organic matter from land to the coastal waters and modifiessignificantly before it is discharged to the coastal ocean. Thus, it is important to study thevariations in bacterial abundance in the estuary with reference to changes in organic carbonconcentrations to understand recycling of organic matter. Bacterial abundance wasmeasured along with physical and biogeochemical properties in the surface waters of theGodavari estuary at three fixed locations from April 2009 to March 2010. The high bacteriacounts were associated with peak river discharge (>2000 m3 s-1) and were decreased duringmoderate (<2000 m3 s-1) and no discharge periods. The high bacterial abundance wasassociated with low total organic carbon (TOC) suggesting high bacterial respiration rates.The incubation experiments suggested high bacterial carbon demand and bacterialrespiration rates during peak discharge period compared to low discharge periodindicating that significant amount of allochthonous carbon was utilized during peakdischarge period. In addition to this, the TOC concentrations decreased by ~10-30% inthe estuary before they were discharged to the coastal region suggesting that significantamount of organic carbon was decomposed in the estuary by microbial oxidation. Suchhigh decomposition rates were further supported by warmer waters (>28o C), highnutrients, and low salinity as bacterial metabolism is more active in such conditions thanmarine waters with low nutrients. In addition to this, high bacterial numbers were alsofound during May and October when phytoplankton blooms were occurred suggestingthat in situ production of organic carbon might have supported bacterial carbon demand.Incubation experiments suggested that heterotrophic respiration is several folds higherthan the autotrophic production and oxidation of allochthonous carbon making estuaryas a net sink for organic carbon and strong source for CO

2 to the atmosphere.


ME-3

Studies on Effects of photosynthetically active radiation inChlorophyll a during Post monsoon season off Cochin waters

Minu P, S.S Shaju, G. Archana, P. Muhamed Ashraf, B. Meenakumari*

Central Institute of Fisheries Technology, ICAR, Matsyapuri P.O., Cochin 682 029, India*Indian Council of Agricultural Research (ICAR), New Delhi 110 012

Under water light availability of different waters are impacted by seasonal changes inthe dominant constituents of each class of substance. Availability of underwater light is acritical factor for primary production by phytoplankton in the water column. The relationbetween photosynthetically available radiation and Chlorophyll a concentration has beencarried out during September 2010 to April 2011.The light parameters such as remotesensing reflectance; photosynthetically active radiation (PAR) etc of the water columnhas been examined at 2hours interval using Hyperspectral radiometer. The resultshighlighted that chlorophyll a concentration is directly influenced by photosyntheticallyactive radiation. The variability of chlorophyll a with seasons is due to the attenuation oflight by change in suspended particles and CDOM. The results suggest that factorsaffecting light attenuation should be considered during the modelling of algorithms forremote sensing applications.

Key words: PAR, Chlorophyll absorption, CDOM, Radiometer

ME-4

Vertical and Horizontal Distribution of Chlorophyll ‘A’ andPhytoplankton from Pondicherry-nagapattinam Waters,

Southeast Coast of India

P. Sampathkumar, K. Kamalakannan, C. Thenmozhi, R. Sankar and

T. Balasubramanian

Annamalai University, Parangipettai- 608 502

The present study was carried out to know the vertical and horizontal distribution ofChlorophyll ‘a’ and Phytoplankton from 3 different stations viz. Pondicherry, Parangipettaiand Nagapattinam for a period of one Year from April 2009 to March 2010. The samplingswere carried out at a distance of 0.5Km, 1Km, 1.5Km, 2.0Km, 2.5Km and 3Km from theshore and vertically at various depths viz. 5m, 10m and 15m. Dissolved oxygen contentranged from 4.089mgl-1 to 5.329 mg l-1, Chlorophyll ‘a’ ranged from 0.019µgl-1 (at surfacewaters) to 54.765 µgl-1 (15m depth) and the Primary productivity values ranged from



6.0mgCm-3hr-1 to 189.31 mgCm-3hr-1 from all the three stations. In general the Chlorophyll‘a’, Primary Productivity and Dissolved Oxygen concentration were higher during summerseason than the other seasons. The present study recorded a total of 87 species of planktonicdiatoms, 25 species of dinoflagellates and 2 species of blue-green algae from all the3 stations. Simple correlation (r) was made for the statistical interpretation of the dissolvedoxygen, Primary productivity, Chlorophyll ‘a’ and phytoplankton distribution.

ME-5

Seasonality in the Distribution and Abundance ofMacrobenthic Fauna in the Cochin Estuary and Adjacent

Coastal Shelf

T.V. Rehitha, N. V. Madhu, R. Reshmi, G. Vijay John and C. Revichandran

National Institute of Oceanography, Regional Centre, Kochi-682018

Seasonal changes in the distribution and abundance of macrobenthic fauna of the Cochinestuary and adjoining coastal waters were studied during the premonsoon and monsoon2010. During the premonsoon, the estuary was dominated by high salinity waters(24.5±7.4) due to the incursion of seawater, while during monsoon, the system was floodedwith freshwater (2.6 ± 3.1) due to heavy river discharge associated with the torrentialrainfall. Generally, the sediment texture was silty clay and clayey sand in the estuaryduring the premonsoon and monsoon periods, whereas it was silty clay and sandy clayrespectively in the coastal waters. A distinct spatio-temporal variation in macrobenthicabundance was evidenced in the study area, in which higher abundance was occurredboth in the estuary (av. 2055 ind. m-2) as well as in the coastal waters (av. 2080 ind. m-2)during the premonsoon as compared to the monsoon period (av. 1480 ind. m-2 & av. 886ind. m-2). Polychaetes formed the most abundant group (50-90%) in the estuary, mostlybelong to the family Capitellidae and Spionidae, which followed by Oligochaetes, Bivalves,Gastropods, Amphipods, Isopods, Decapods etc. On the other hand, Foraminifera wasthe predominant group in the coastal waters, followed by Polychaetes, Bivalves,Gastropods and Amphipods.

Key words:- Macrobenthos, Cochin estuary, Polychaetes, Foraminifera, Monsoon


ME-6

Plankton metabolic activity and its role on dissolved organiccarbon dynamics in a tropical lagoon, Chilika: India

K.Vishnu Vardhana*, R.S.Robina, Pradipta R Mudulia, B.Charan Kumarb,

A.Lova Rajub, D.Gangulya, S.Patraa, G.Nageswara Raoc, A.V.Ramanb and

B.R.Subramaniana

aICMAM Project Directorate, Ministry of Earth Sciences, NIOT Campus, Chennai 600 100, IndiabDepartment of Zoology, MB Laboratory Andhra University, Visakhapatnam 530013, India

cDepartment of Inorganic and Analytical Chemistry, Andhra University, Visakhapatnam 530013, India

In recent years, the carbon cycle has receives more attention by the researchers due to theincrease of carbon dioxide in the atmosphere and the adverse climate change caused bythe green house effect. Organic matter is one of the biggest carbon reservoirs in the worldand plays an important role in biogeochemical cycles of carbon in the marine and coastalenvironments. Dynamics of dissolved organic carbon (DOC) and particulate organiccarbon (POC) was studied at 35 stations in the Chilika Lagoon during May (Premonsoon)and October (Monsoon) 2009. Mean DOC & POC concentrations were found to be 309.7±171.8µM & 239.3± 224µM during premonsoon and 200 ± 77.4µM & 128.5 ± 73.37µM duringmonsoon, respectively. Both showed a distinct spatial and temporal distribution alongthe salinity gradient. Earlier studies revealed that DOC was influenced by various physical,chemical, and biological processes. Production of new organic carbon (primaryproduction) is one of the factors that could lead to alter the DOC concentrations in thelagoon through the metabolic activity of phytoplankton. Therefore, we studied the primaryproduction (POC) and rate of extra cellular released DOC using liquid scintillationcounting technique at 11 stations representing the entire lagoon. The extracellular releaseof DOC was found to be highest in central sector followed by northern, southern andouter channel. Results showed that the production of DOC and POC varied from 15.8 –77.8 mg C m3d-1 & 82 – 296 mg C m3d-1 during premonsoon and 12.9 - 69.2 mg C m3d-1 &62.5 – 182.3 mg C m3d-1 during monsoon, respectively. Significant positive correlationwas observed irrespective of seasons between POC and extracellular released organiccarbon. The percentage of extracellular released organic carbon was varied from 12.6-21.3% (Premonsoon) and 17.2-28.6% (Monsoon) that of the new production of POC. Thisindicated that as a net ~20% of the fixed inorganic carbon in the lagoon was instantaneouslyaccessible for the mineralization process. Monsoonal impact lead to a reduction in theprimary production by 42.8% with that of premonsoon where as the extracellular releasedecreased only 26.6% signifying the importance of external stress on DOC dynamics.

Keywords: Plankton metabolism, extracellular release, dissolved organic carbon dynamics,Chilika Lagoon, New production



ME-7

Influence of allochthonous input on trophic switch over andCO

2efflux in a shallow tropical lagoon Chilika lagoon, India

R.S. Robina*, Pradipta R. Mudulia, K.VishnuVardhana, B. CharanKumarb,Shoji

D. Thottathild, U.S.Pandaa, Sivaji Patraa, T. Balasubramanianc, A.V. Ramanb

and B.R. Subramaniana

aICMAM Project Directorate, Ministry of Earth Sciences, NIOT Campus,Pallikaranai, Chennai 600 100, IndiabDepartment of Zoology, Marine Biological Laboratory, Andhra University, Visakhapatnam 530 013, India

cCentre of Advanced Study in Marine Biology, Faculty of Marine Science,Annamalai University,Parangipettai, 608 502. Tamil Nadu, India.

dCentre for Ecological Research, Kyoto University, Japan

In the last decade, a lot of effort has been put to understand the role ofheterotrophicbacterioplankton in the proceses of organic carbon in aquatic systems.Knowledge of primary productivity (PP), bacterial productivity (BP), bacterial abundance(BA) and bacterial respiration (BR) are prerequisiteto understand the transformation andmineralization of organic matter as the balance between these variables determines thetrophic status of the system. As known the BP/PP and PP/BR ratios are >1 and <1, thesystem becomes heterotrophic and vice versa, soBP, BA and BR were examined in relationto PP for the first time in the Chilika Lagoon during 2009for the estimationof its trophicstatus. The seasonal variation of BP ranged from23.33 – 99.3, 28.49 – 176.23 and 23.33 –99.3 µg C L-1 d-1 during pre-monsoon, monsoon and post-monsoon respectively. BR variedfrom 16.33 – 331.3 µg C L-1 d-1 inpre-monsoon, 19.15 – 397.37µg C L-1 d-1 in monsoon and11.25 – 320.7 µg C L-1 d-1 during post-monsoon. BA exhibited spatial and temporalvariability ranging from 0.32x 109 to 1.45 x 109 cells L-1 and was significantly correlatedwith lagoon salinity (p< 0.01). BA during the southwest monsoon (1.45 ± 0.57 x 109 cells L-

1) and post-monsoon (1.11 ± 0.47 x 109 cells L-1) were higher than pre-monsoon (0.97 ± 0.43x 109 cells L-1). During pre-monsoon,PP was in the order of 66 – 884 µg C L-1 d-1 and itranged 24 – 872 µg C L-1 d-1, 76 – 764 µg C L-1 d-1during monsoon and post-monsoonrespectively. A wide spatial and temporal variation in the tropic status were observed inthe lagoon apparent by BP/PP(0.02 – 4.25) and PP/BR (0.15 – 44.12) ratios. Thenet pelagicseasonal shift in production from autotrophy to heterotrophy due to terrestrial organicmatter inputsviarivers enhanced the bacterial heterotropyas well aspCO

2 (10134µatm)

during the monsoon. Corresponding net CO2 efflux was -26.51 to 311.35 mmol m-2 d-1 and

-26.66 to 427.41 mmol m-2 d-1 during pre-monsoon and post-monsoon respectively.However, its magnitude was two fold higher during the monsoon (-24.18 % 713.52 mmolm-2 d-1). The north sector of the lagoon wasidentified as heterotrophic andcharacterizedby low PP, high BP and high BR, which leads to oxygen undersaturation and exceptionally


high pCO2. This study reveals that the elevated CO

2supersaturation in the northern sector

caused by increased bacterial respiration (in excess of PP) was a result of bacterialdegradation of allochthonous organic matter.Alsoit indicates,the lagoon being part ofcoastal ecosystem, receives huge riverine organic flux during summer monsoon with 60%annual rain fall (June-September). A major fraction of this organic load gets trapped andbiologically respired making the system a net source of CO

2 to the atmosphere instead of

exporting to the sea. As a pioneering attempt, our studies on seasonal and temporalvariations in bacterioplankton biomass, production and respiration along with dissolvedgases (O

2 and CO

2) revealed that lagoon acts as ‘‘net autotrophic’’ during pre-monsoon

and post-monsoon, whereas ‘‘net heterotrophic’’duringmonsoon. Onspatial scale south,central and outer channel recorded ‘‘net autotrophic’’, while the northern sector shows‘‘netheterotrophic’’ during all the season.

Keywords: Primary Productivity; Bacterial Productivity; Respiration; CO2Supersaturation;

Heterotrophy; Tropical Estuary.

ME-8

Estimating Chlorophyll-a Concentration using first -Derivative Spectra in Coastal Waters of Bay of Bengal

along East Coast of India

K.Gopala Reddy, Srikanth Ayyala Somayajula, B. Srinivasa Rao

Center for Studies on Bay of Bengal, Andhra University, Visakhapatnam

The technique of derivative analysis is applied to estimate algal chlorophyll concentrationin Western Bay of Bengal coastal waters along East Coast of India. The data was collectedover different sampling stations during January to May-2010. A Satlantic™ hyperspectralocean colour radiometer (HyperOCR) was used for measuring downwelling irradiance(E

d (ë, z)), downwelling irradiance reaching the sea surface (E

s (ë)), and upwelling radiance

(Lu

(ë, z)), measurements. The instrument operates in 255 channels of optical data withwavelengths ranging from 300 to 1200 nm (350 to 800 nm standard) with a bandwidth of± 10 nm in visible bands and ± 20 nm in near infrared (NIR) bands. The results indicatedthat first derivatives at 490-500 nm, 555 – 565 nm and 670-680 nm were correlated stronglywith chlorophyll-a. The R values reached 0.91 for the wavelengths from 555-565nm. Theresults shows that the derivative spectra are an effective tool for estimating chlorophyllconcentration and support the hypothesis that derivative spectra are less impacted bywave effects.



ME-9

Application of a Ecosystem Model to Study the Dynamics ofNutrients in Chilika Lagoon

Uma Sankar Panda, Sivaji Patra, R.S. Robin, K.VishnuVardhan,

Pradipta R. Muduli, D. Ganguly and B. R. Subramanian

ICMAM-PD, NIOT Campus, Chennai-600100

To illustrate and calculate the important physical, chemical and biological processes ofthe lagoonal ecosystem of Chilika (N 190 28’-190 54’; E 850 06’-850 35’), a coupledhydrodynamic, advection-dispersion and ecosystem model has been developed usingMike 21 modelling tools. The current study provides a concept to develop a new ecosystemmodel for a complex and dynamic coastal environment where significant spatial andtemporal variation prevailed. The conceptual model is successfully calibrated and is ableto simulate the spatial and temporal variation of Chlorophyll, nutrients and other waterquality constitutes in response to the variation of boundary and weather conditions.Validations are being made with the in-situ observed data. The skill test shows a goodagreement of the simulated parameters. These result shows that, in the northern andcentral sector, the variation of water quality constituents such as COD, Chl-a, PO

4–P and

DIN follows a seasonal pattern, high during the rainy seasons and low during winter.This is because runoff from land areas during the rainy seasons contributes nutrientsload and runoff water dilutes seawater in areas near the inlet. Totoal loadings of nutrientshave been estimated for each sectors of the lagoon. The model is found to be able tocompute the mass budgets and residence time.

ME-10

Distribution of Benthic Polychaete Species and relation withBiogeochemical factors in East Coast of India

S.A. Naidu, and V.V.S.S. Sarma

National Institute of Oceanography (CSIR), Regional Centre, Visakhapatnam

Benthic Polychaetes are the dominant taxa in marine environment and play key role infood chain at various trophic levels. Several studies have been conducted in the east andwest coast of India to understand their distribution however influence of water columnand sediment properties on their distribution is rather sparse. In this study 18 sedimentsamples were collected off mouth of estuaries in the east coast of India during peakdischarge period (July-August 2010) at a depth of 25, 50, and 100 m. Surface water


phytoplankton biomass, represented as chlorophyll-a, increased towards northwesterncoastal Bay of Bengal, where low suspended sediment matter was observed. This led topenetration of light into the water column and increase in phytoplankton biomass.Dissolved oxygen concentrations were also decreased to <10 mM at 100 m water columndepth in the northwestern coastal Bay due to high production in the surface resultingenhanced sinking carbon and their microbial degradation at depth. The sediment organiccarbon increased towards northwest and their isotopic ratios suggests >60% of organiccarbon has marine origin in the north. All these conditions in the northwestern coastalBay of Bengal are conducive for benthic plankton growth. A total of sixty five polychaetetaxa were identified in the study region. The density of polychaete taxa were increasedtowards northwestern coastal Bay of Bengal from south and it was consistent with watercolumn and sediment characteristics. High diversity was observed close to the coast (at25 and 50 m) and decreased towards offshore. The dominant species in south and northwere Prionospio pinnata, Nephtys cornuta, and Ancystrosyills parva, Lumbrenereis sp

respectively. Lavinsenia Spp., A .parva Spp. Cossura coasta were numerically significant atthe offshore stations (100 m) off river Krishna, Mahanadi and Godavari whereas Prionospio

spp. is dominant close to the coast (<50 m water column depth) off Krishna and Godavarithan offshore. Occurrence of deposit feeders and organic indicator species were decreasedtowards offshore and it is consistent with the organic carbon content in the sediments.This study therefore suggests that spatial distribution of polychaetes were mainlycontrolled by the water column and sediment characteristics along the east coast of India.

Keywords: Benthos, Polychaete, in fauna, Bay of Bengal, organic carbon, and Chlorophyll.

ME-11

Meso-scale Atmospheric Events Promote PhytoplanktonBlooms in the Coastal Bay of Bengal

K. MANEESHA, and V.V.S.S. SARMA

National Institute of Oceanography, Visakhapatnam

The Bay of Bengal is considered to be a low productive region compared to the ArabianSea based on conventional seasonal observations. Such seasonal observations are notrepresentative of a calendar year since the conventional approach might miss episodichigh productive events associated with extreme atmospheric processes. We examinedhere influence of extreme episodic atmospheric events, such as heavy rainfall and cyclone,on phytoplankton biomass in the western Bay of Bengal using both in situ time-seriesobservations and satellite derived chlorophyll-a (Chl-a) and Sea Surface Temperature(SST). Four times increase in Chl-a concentration in the coastal Bay was observed in two



weeks following the supply of nutrients through runoff driven by episodic heavy rainfall(234 mm) on 4-5th October 2007. Similar increase in Chl-a, by 3 to 10 times, was observedon the right side of the cyclone Sidr track in the central Bay of Bengal. These two episodicevents caused phytoplankton blooms in the western Bay of Bengal which enhanced ~40%of fishery production during October-December 2007 compared to that in the same periodin 2006. Therefore it is important to include influence of episodic events on annualproduction when it is compared with the adjacent basin, Arabian Sea.

ME-12

Environmental Factors Controlled by Phytoplankton biomassand Production rate in the Estuarine Waters of Cochin

Dayala V.T and Sujatha C.H

Department of Chemical Oceanography, CUSAT, Cochin.

The spatial and seasonal variations in hydrographic conditions offered by the estuarinewaters of Cochin, helps to understand the relationship between physico chemical variablesand phytoplankton abundance, which form the main objective of the present study. Cochinestuary one of the largest estuary in India (256km2), this micro tidal estuary undergo acharacteristic transformation from a river dominated system during summer monsoon,to a tide dominated system during pre monsoon season. The estuary is enriched by theenormous input of nutrients (nitrite, nitrate, phosphate and ammonia) from varioussources was responsible for the high phytoplankton biomass irrespective of seasons. Thechanges in the phytoplankton biomass, production rate and species composition werestudied during the year (2009-2010), of three seasons with respect to environmentalparameters. The phytoplankton community was in general dominated by diatoms in premonsoon season. The optimum nutrients and light intensity prevailing the mesotrophiccondition have enhanced the abundance of diatoms in the estuary. During post monsoonseason, the light limitation due to high turbidity reduces the diatom growth and abundanceeven though high nutrients level exists. In monsoon the flora was only constituted bygreen algae and the abundance was very low. The production of phytoplankton in theCochin estuary varies seasonally and is found to be sensitive to the environment.

Keywords: Cochin estuary, phytoplankton, environmental parameters


ME-13

Diurnal variation of Plankton in Godavari Estuary

M.D. Bharathi, V. Venkataramana and V.V.S.S. Sarma


Diurnal variations in plankton (phyto and mesozooplankton) composition were measuredat fixed location in the Godavari estuary during wet and dry periods. Phytoplanktoncomposition during dry period (February) was dominated by Bacillariophyceae followedby cyanophyceae and dinophyceae. On the other hand, cyanophyceae was dominantduring wet period (June) followed by Bacillariophyceae and dinophyceae. The diurnalvariations in the phytoplankton abundance and composition followed tidal cycle viz highabundance associated with high tide and vice versa during dry period and contrasting tothat was observed during wet period. The major diatoms species, namely Coscinodiscus,

Merismopedia, Nostoc, Nitzchia, Thalassiosira spp. were high during low tide than high tidein wet period and same species showed opposite behavior during dry period. Over all,mesozooplankton biomass was higher during high tide than low tide during both wetand dry periods. Such behavior was mainly driven by high mesozooplankton abundanceat the mouth than upstream. In addition to this, mesozooplankton abundance was anorder of magnitude higher during wet period than dry period. This suggests that thedifferent behavior of phytoplankton to tides during wet and dry period were driven bygrazing pressure rather than tidal influence alone. The grazing rate during June was 1.5d-1 which was lower by 3 times during February (0.5 d-1). Such high grazing pressureduring June influenced diversity and dominance of phytoplankton as well. For instance,dominance and diversity was 0.810±0.11 and 0.232±0.11 during dry period whereas itwas 0.398±0.056 and 0.56±3.39 respectively during wet period. Due to stable condition,saline water and less grazing pressure resulting in high dominance during dry than wetperiod. On the other hand, high stratification and less residence time of water (low flushingrates) in wet period resulting in high diversity. Bacillariophyceae contributed ~98% and2% by cyanophyceae during dry period whereas bacillariophyceae contributed 26% and73% by cynophyceae during wet period.



ME-14

Influence of River Discharge on Phytoplankton CommunityStructure in the Coastal Bay of Bengal

D. Bandhopadhyay, T. Acharyya, and V.V.S.S. Sarma


The Bay of Bengal receives an enormous amount of fresh water from the major rivers,such as the Ganges, Brahmaputra, Godavari, Mahanadi, Cauvery, Irrawady, and Krishna(1.6 × 1012 m3 a”1), and high precipitation (~2 m a”1). The river system delivers the majorparts of its annual average sediment load (1.1 × 109 t) during June to September and thefluvial inputs are major sources of nutrients to the Bay of Bengal. In order to examine thebiogeochemical characteristics of different rivers and their influences on phytoplanktondynamics in the coastal Bay of Bengal, samples were collected from off river mouthsalong the east coast of India during the peak discharge period (July-August, 2010). It wasobserved that suspended particulate matter (SPM) was relatively higher in thesouthwestern coastal Bay with an average load of ~50 mg/l and it was decreased to <20mg/l in the northwestern coastal Bay and similar distribution pattern was observed fornutrients as well. As a result of increase in light penetration in the north led to enhancedphytoplankton biomass and decrease in nutrients in the northwest than southwesterncoastal Bay. Phytoplankton pigments also showed contrasting differences betweensouthwest and northwestern coastal Bay. Fucoxanthin (diatoms) concentration was less(<1ug/L) in the southwest and increased significantly (2 to 3 ug L-1) in the northwest andcontrasting to this was observed for perdinin (dinoflagellates). Such spatial differenceswere mainly caused by different nutrient ratios in the coastal Bay of Bengal. The meanN:P ratios in the southwest was ~8.1 whereas it was ~5.0 in the northwestern Bay. Lowammonium and nitrate concentrations were observed in the northwestern Bay where highdinoflagellates were observed due to their preferential consumption of reduced nutrients.Though high ammonium concentrations were observed in the southwestern Bay howeverdinoflagellates were almost absent due to non-availability of light driven by highsuspended load. On the other hand, zeaxanthin concentration did not show contrastingdifferences between north and south except that higher concentrations were observed offGodavari and Mahanadi where high ammonium concentrations were observed. Inconclusion, physical and biogeochemical properties such as salinity, nutrients ratios andsuspended matter, play a great role on phytoplankton community structure in the coastalBay of Bengal.


ME-15

Development of Water Quality Index for Coastal Region ofVisakhapatnam Using Statistical Techniques

Sangeeta Pati, M. K. Dash, C. K. Mukherjee and B. DashIndian Institute of Technology Kharagpur

*Central Marine Fisheries Research Institute, Visakhapatnam

Continuous monitoring of physical, chemical and biological parameters of coastal waterin a continuous manner is very essential for Marine Aquaculture. So it is desired to turncomplex water quality data into a single number that expresses overall water quality of acertain location at a particular time. This paper proposes a technique to describe the waterquality quantitatively for the marine aquaculture from multiple measured water qualityparameters through an index called Water Quality Index (WQI). Different water qualityparameters, like Dissolve Oxygen (DO), Biological Oxygen Demand (BOD), TotalSuspended Solid (TSS), Ammonia (NH

3), Phosphate (PO

4), Nitrate (NO

3) at different depth

has been collected for each month for 0.8° (along latitude) ×0.2° (along longitude) boxnear Visakhapatnam coastal zone of Bay of Bengal from 2007 to 2010.

Theses data have been classified into number of groups using multivariate analysis.Hierarchical Agglomerative Cluster Analysis (HACA) is carried out in the Euclidean spaceto classify the groups. Three groups of water quality i.e. good, average and poor havebeen identified. The groups are undergone F test and found statistically significant under1% level of significance. The relation between any two groups has been studied usingdiscriminant function analysis. A suitable discriminant function has been generated todescribe the maximum variance in the data set. Group centroids are calculated using thediscriminant function for each group. The WQI has been generated using these valuesand found within the range -1 to +1. The negative value representing the centroid forpotentially good and positive value representing poor water quality based on the eigenvalues assigned to each water quality parameters. The interval -1 to +1 establishes a rangeof average condition of coastal water. The WQI derived using this method has been testedtaking some random samples and found to be robust. This work has shown that WQIgenerated using this multivariate procedures proved to be an efficient tool to understandthe status of the coastal water.



ME-16

“River discharge”: A Critical Factor ControllingPhytoplankton Biomass and Community Composition in

Monsoon driven Godavari Estuary

T. Acharyya, D.Bandyopadhyay and V.V.S.S. Sarma

National Institute of Oceanography, Visakhapatnam – 530017

Indian subcontinent houses some of the worlds’ largest estuaries (Ganges, Godavari,Krishna, Narmada etc.) which plays prominent role in particulate organic carbon (POC)fluxes in the adjacent coastal ocean. A major portion of that POC is contributed by estuarinephytoplankton and it is customary to understand their fate all through their journey fromestuary to sea. Additionally, phytoplankton, which lie at or near the bottom of the foodchain, support secondary and tertiary production in the estuary in terms of economicallyimportant fish, prawn and mollusc. However, the phytoplankton community composition,species succession pattern and their dynamics, both in terms of spatial and temporalscales, are fairly unknown in this region.

To address this knowledge gap, three year (2007-2009) extensive daily time seriesobservation was carried out in the Godavari river estuary which opens into the Bay ofBengal, east coast of India. Our observation suggests that Godavari estuary is characterisedby high flushing rate and turbid water column during the peak monsoon season (July-September). Even though a lot of nutrient is brought into the estuary by this time,phytoplankton population are not able to increase their biomass due to severe lightlimitation. During the withdrawal phase of monsoon (by October), consequent reductionin the discharge volume coupled with stronger incursion of the tidal wedge stratifies andstabilises the water column. A month long phytoplankton bloom (contributed byCyanobacteria) coincides with this stratification event, which we call as the ‘major bloom’.Crashing of this bloom takes place when salinity in the estuary gradually peaks up byNovember which put Cyanobacteria under osmotic stress. Our in-vitro experimentsuggests the salinity tolerance maxima of the inhabiting Cyanobacteria population inGodavari river estuary is about 16 PSU( Practical Salinity Unit).Niche left by Cyanobacteriais steadily occupied by diatoms which are far more salt tolerant and thrive in the clearerwater column. Diatom population contribute a ‘minor bloom’ by April and sustain theirstanding stock until the next cycle of discharge starts by July. Major bloom intensity aswell as the bloom sustenance was enhanced from 2007-2009 which is inversely correlatedwith volume of discharge that facilitated enhanced stability and higher residence time ofthe water parcel in the estuary. Sensitivity of the Indian estuaries towards the


eutrophication and thus overall health of these ecosystems is tuned by variability inmonsoon rainfall. It requires further study keeping in mind with the climate changescenario that would bring inevitable change in the rainfall pattern.

ME-17

Coastal and off shore Phytoplankton Pigment Profile ofNorth Bay of Bengal with reference to TSM and Turbidity

Sanghamitra Palleyi, R. N. Kar and C. R. Panda

Institute of Minerals and Materials Technology, Bhubaneswar

The coastal Bay of Bengal is a unique marine environment in the tropical belt with markedcontinental influence due to the drainage by a large number of rivers. The Bay of Bengalis considered to be low-productive zone which is strongly affected by monsoons, stormsurges, and cyclones but has no seasonal upwelling. The Bay of Bengal marine ecosystemis considered a Class II, moderately productive ecosystem based on SeaWiFS globalprimary productivity estimates. In such a significant area, knowledge of phytoplanktondynamics and distributions is vital to ensure a scientific basis for coherent managementof the coastal environment and the human activities which impact on or benefit from it.Extensive study was conducted to investigate the phytoplankton pigment spectrum, andassociated water chemistry of Bay of Bengal region from Odisha to West Bengal. Watersamples were collected for pigment analysis from near shore to off shore regions of Bayof Bengal, conducting different cruises during the year 2009-2011.

The objective of this study is to generate in situ data on pigment profile which will behelpful for monitoring programs to assess environmental controls on ecosystem structureand function over varying spatial and temporal scales on the areas of Bay of Bengal regionfrom Odisha to West Bengal. Large scale study over oceanic and near-shore regionrevealed that high concentrations of pigment were observed near the estuarine region.Result of Chlorophyll-a distribution patterns during 2009-10 ranged from 0.23-8.80 µg/lin the near shore regions and 0.02-4.48 µg/l in the off shore regions. The upper range ofpigment concentration was observed at the near shore region of Dhamra estuary duringDecember’10. Chlorophyll concentrations of 3.74-8.80 µg/l at Dhamra have been observedas a consequence of high proliferation rate of phytoplanktons during winter. The off shoreactive chl-a and pheopigment concentration was highest in Dhamra transect i.e. 4.2186µg/l and 2.7661 µg/l respectively. Carotenoid pigment (photo protective pigment) wasalso highest in Dhamra (1.3381 µg/l) in comparison to Mahanadi and Haladia transect.Higher concentration of pheopigment in the off shore regions of Mahanadi and Dhamratransect at 10 and 20 meter depth indicates high rate of grazing. The vertical distribution



of pigment reveals that at Dhamra off shore transect the pigment distribution in the shoreline area was very much stratified in comparison to Mahanadi and Haladia. At Mahanaditransect the subsurface and bottom layer chlorophyll maxima were observed after 20meter depth. A positive relationship was observed for TSM, turbidity and primaryproductivity with chlorophyll. During October’10 at the near shore region of Dhamraestuary, the relationship of TSM and turbidity with chlorophyll is found to be inverse.Among TSM and turbidity, turbidity has got a strong relationship with chlorophyll.

ME-18

Spatial Distribution of Zooplankton alongOrissa Coast in Dry Season

Suchismita Srichandan, N. C. Rout and C. R. Panda

Institute of minerals and Materials Technology, Bhubaneswar

Oceans are Earth’s most distinctive feature covering about 71% of its surface. The entirespectrum of life found in the pelagic realm of oceans and their associated coastalembayment are categorised under three basic types, namely plankton, nekton andpleuston. The plankton community is divided into three groups; (1) phytoplankton(plants), (2) zooplankton (animals), and (3) bacterioplankton (bacteria). Zooplanktonrepresents an important component of marine life forming important compartment(s) offood web between the primary producer phytoplankton and carnivorous fish. In fact,success or failure of the fisheries of the coastal waters often depend upon the zooplanktonproduction. The goal of this study is to determine the spatial distribution of zooplanktonrelative to the ecological characteristics from nine coastal areas of importance of Orissacoast such as Gopalpur (port and industrial area), Rushikulya (ecologically sensitive area),Chilika (Ramsar Site), Puri (a moderately urbanized area), Konark (pollution due totownship sewage), Paradip (port and industrial area), Mahanadi (effluents from fertiliserand phosphate industries brings attention), Dhamra (highly influenced by agriculturalrun-off) and Chandipur (municipal sewage affected). The study was conducted duringsummer season (March/ April) of 2010. The ranges of air and surface water temperatures(°c) were 26.40 – 35.70 and 27.10 – 30.20 respectively. pH, salinity (PSU), DO (mg/l), andBOD (mg/l) values varied from 8.13– 8.45, 24.32 – 28.96, 6.55 – 7.90 and 0.36 – 3.26. Theinorganic nutrients (mmol/l) viz. nitrate, nitrite, ammonia, phosphate and silicate variedfrom 1.15 –20.11, 0.12 – 1.15, 0.27 – 4.02, 0.13 – 2.81 and 3.96 – 17.06. Zooplankton densityand biomass ranged from 481 – 5685 nos.m-3and 0.04 – 9.60 ml m-3 respectively. Simplecorrelation analyses were made between the zooplankton density with ambient watertemp, salinity, dissolved oxygen, biological oxygen demand, nitrite, nitrate, ammonia,


phosphate, silicate, chl-a contents, phytoplankton standing stock and zooplankton biomassto assess the influence of these hydrographic features and phytoplankton standing stockon zooplankton distribution in Orissa coast. The density of zooplankton was maximumat Mahanadi and minimum at Gopalpur. Totally forty groups of zooplankton wererecorded. Out of the 40 zooplankton forms, 22 groups belonging to holoplankton and 18different types of meroplankton were encountered. Among the holoplankton copepodformed the dominant group at all the sampling sites. The presence and array of juvenileforms in the dry season suggest that the coastal water remain a sanctuary, nursery andbreeding grounds for aquatic species. Crustaceans dominated the spectrum of the juvenileforms.

ME-19

Oscillating Environmental Responses of theEastern Arabian Sea

Vijay John Gerson, Madhu. N. V, Jyothibabu. R, Balachandran. K. K,

Maheswari Nair, Revichandran C.

National Institute of Oceanography, Regional Centre, Kochi-682018

Characteristics of two distinct physical processes, the coastal upwelling and convectiveoverturning, which enhance phytoplankton productivity in the west coast of India, arediscussed in this paper using the comprehensive in-situ data collected during two monsoon(summer and winter) periods. During northwest monsoon (NWM), the process of winterconvective mixing lead to occurrence of cold sea surface temperature (25-26°C), deeperMLD (>70m) and higher nutrient levels (1-2µM) in the upper water column (above 100m)of the northeastern Arabian Sea. In addition, pronounced oxygen deficient conditionwas also observed in the intermediate depths (150-300m) of the northeastern Arabian Seaduring this period. On the other hand during the southwest monsoon (SWM), the processof coastal upwelling causes the incidence of colder (27°C), low oxygenated (<190µM),nutrient rich (nitrate- >2µM) water in the southeastern AS. In both regions, phytoplanktonbiomass (chlorophyll a) was relatively higher (av. > 2mg m-3) during both NWM and SWMperiods due to the elevated levels of nitrate (1-2µM). Even though both processes enhancephytoplankton growth in the west coast of India, the time and area of occurrence foundto be entirely different. Physically forced chemical changes in the upper layers appear toplay a key role in phytoplankton response, which enhances the primary productivity andimpart an oscillating environmental condition to the eastern Arabian Sea.

Key words: Upwelling, winter cooling, nutrients, chlorophyll a, primary production



ABSTRACTS

THEME-10 (B) BIO-GEO CHEMISTRY OF OCEANS


BCO-1

Variability of DMS and its Related Compoundsalong the East Coast of India

R. Viswanadham, V.D. Rao and V.V.S.S. Sarma


A systematic time series study of Dimethyl sulphide and supporting biogeochemicalparameters has been carried out along the east coast of India. Two different locationswere selected for the proposed study, i) The Goutami Godavari Estuary(GGE) ii) coastalwaters off Vishakhapatnam (VSP). The DMS and its precursor Dimethylsulphoniopropionate (DMSPt) concentrations ranged from 0.10nM to 60.84nM and 0.14nMto 48.95nM respectively at GGE. The concentrations are increasing towards coast withmaximum concentrations occurring at the mouth of the estuary. DMS and DMSPt atupstream are correlated with biomass (Chlorophyll) but such significant correlation isnot observed in the coastal waters off GGE. This difference was caused due to highcontribution of DMS releasing phytoplankton (Chlorophyceae) in the upstream to thetotal phytoplankton biomass whereas high diversity was noticed in the downstream ofGGE. Observed DMS and DMSPt off VSP are in correlation with biomass with highestconcentrations found at sub surface depths of near coastal stations with decreasedconcentrations away from the coast. The DMS and DMSPt off VSP were contributed bydiatoms in the surface while dinoflagellates in the subsurface. The range of concentrationsfor DMS and DMSPt off VSP are lower (0.5 to 19.5 nM and 0.3 to 33.5nM respectively)than off GGE due to low biomass of DMS contributing phytoplankton.

BCO-2

Temporal Variability of Dissolved Inorganic Carbon Budgetfrom a Tropical Shallow Lagoon, Chilika, India

Prdipta.R.Mudulia, K.Vishnu Vardhana, R.S. Robina, B. Charan Kumarb,

A.Chandra Moulib, U.S.Pandaa, Sivaji Patraa, G. Nageswarara Raoc,

A.V.Ramanb, B.R. Subramaniana

aICMAM Project Directorate, Ministry of Earth Sciences, NIOT Campus, Chennai 600 100, IndiabDepartment of Zoology, Andhra University, Visakhapatnam 530 013, India

cDepartment of Inorganic and Analytical Chemistry, Andhra University, Visakhapatnam 530 013, India

A land ocean interaction in coastal zone (LOICZ) biochemical model was applied on asemi enclosed Chilika lagoon in seasonal basis (Active flow and Lean flow) to obtain



water, salt and dissolved inorganic carbon (DIC) budget. The result suggests that therewas a net water flux and salt residual flux towards coastal waters from lagoon, duringboth active and lean flow period. This study revealed that exchange between lagoon waterwith the ocean replaces this exported salt via mixing.The estimated freshwater dischargesin to the lagoon was 3.69 x 106 m3 d-1 during the lean flow and as high as 28.34 x 106 m3 d-

1 in active flow. Water residence time during active and lean flow was calculated to be 45and 147 days, respectively. The non-conservative DIC budget (“DIC

sys) showed the lagoon

served as a net sink of DIC and its magnitude increases three fold higher during activeperiod than that of the lean period.Seasonal variation of riverine DIC flux shows a stronginfluence on its residual and mixing fluxes. DIC flux was found six times lower duringlean flow (Vr DICr =6.08 x 109 m3 d-1) than that of active flow (Vr DICr =38.45 x 109 m3 d-1).Higher mixing flux (-7625.75 m3 d-1) during active flow relative to the lean flow (-1698.06m3 d-1) indicated that the lagoon acts as net sink of DIC. The residence time of DIC in thelagoon water was almost twice the water residence time during both active(76 days) andlean (349 days) flow.Since the resident time of DIC is longer than the water residencetime, it could be possible to allow the active biological uptake, which is evident fromestimated negative “DIC

sys during both periods. Application of LOICZ biochemical model

on the lagoon DIC leads to the accurate estimation of advective transport of DIC whichcould give new insight to carbon biogeochemistry.

Keywords: DIC flux, LOICZ, non-conservative flux, budgets, Chilika lagoon

BCO-3

Source and Fate of Terrestrial Organic Carbon in Sedimentsalong the East Coast of India

MSR Krishna, VVSS Sarma, Lata G, SA Naidu, Ch V Subbaiah and

P Praveen Kumar

National Institute of Oceanography – Regional Centre, Visakhapatnam, India

Rivers transport huge amount of terrestrial organic matter to the coastal ocean via estuaries.Most of this terrestrial organic matter (~80%) is believed to be recalcitrant and not bio-available. In order to understand the contribution of terrestrial organic carbon and itsmodifications by biogeochemical processes, we determined stable isotopic compositionof organic carbon (ä13C

org) and total nitrogen (ä15N) in the sediments and particulate organic

matter collected along the east coast of India. Isotope ratios of organic carbon (ä13Corg

)ranged from -28.4‰ to -19.2‰ and nitrogen isotopic ratio (ä15N) varied between -8.4‰to 7.2‰ in particulate organic matter. Carbon to nitrogen ratio (C:N) varied broadly


from 2 to 30 with lower ratios in the northern part of the coast. Strongly depleted bothcarbon and nitrogen isotopes and lower C:N ratios in particulate organic matter suggestthat major contribution of terrestrial/artificial material to this region. Using ä13C

org in the

simple two end member mixing model, we computed the contribution of terrestrial organiccarbon to this region and it varied between 5 and 50% with higher terrestrial contributionin the southern part of the coast. In sediments, ä13C

org ranged from -23.3‰ to -17.6‰ and

ä15N varied between 3.7‰ to 13.5‰ in surface sediments. When compared to particulateorganic matter in the surface waters, sediments are enriched by ~6‰ in the case of carbonand ~5‰ in the case of nitrogen indicates that either advection of this terrestrial materialto the deep ocean or the degradation within the water column. From the depletion ofdissolved oxygen concentrations in the sub-surface layers of the water column, it seemsthat most of the terrestrial organic carbon is getting modified/decomposed within thewater column by active biogeochemical processes resulting in the enrichment of carbonand nitrogent isotopic composition.

BCO-4

Seasonal Trends in the Aerosol Components over theCochin Estuarine System

Jose Mathew, Gayathree Devi and Sujatha C.H*

*Department of Chemical Oceanography, CUSAT, Cochin-16, Kerala, India

The physico chemical parameters of ambient atmospheric gases and particulates werepooled over the topographically important, diverse reaction centre on the Cochin EstuarineSystem during the pre and post monsoon of 2010-2011.The Sampling sites selected wereadjacent to the estuarine system which further classified into three zones based on salinity.Water samples were also collected to ascertain an alliance with the atmosphere.Atmospheric gases mainly focused are Sulfur dioxide, Nitrogen dioxide, Ammonia andtrace metal component of the particulate matter. The meteorological parameters like windspeed; direction, temperature, relative humidity and atmospheric pressure were foundto have a firm impact on the dispersive mechanism of the pollutants. Decreasing trendsin the collected gases were observed from the pre to post monsoon. The La Nina and as aresult continuous precipitation may have a choice to this reason. The trace metals studiedinclude Al, Cu, Fe,Cd,and Zn. Iron varied from 0.38 to 0.84ppm. Lead was found to be ina constant ratio which indicates continuous control measures have been adapted.



BCO-5

Seasonal Variation of Physico - Chemical Parameters inrelation to Organo Chlorine Pesticides in the Cochin Estuary

Salas P.M and Sujatha C.H

Department of Chemical Oceanography, Cochin University of Science and Technology, Cochin

Seasonal variations of physicochemical parameters and nutrients were studied in sixdifferent stations of Cochin Estuary, the South West coast of India. Six sampling siteswere selected (9o 47. 646" N and 76o 25 . 708" E to 10o 04.993" N and 76o 17. 906" E) vizKarippadam, Kumblam, Thevara, Bolghaty, Cheranellur and Kalamassery-FACTrepresenting riverine , estuarine and three sampling surveys were conducted seasonallysurface and bottom water and also sediment collected (monsoon-MNS, postmonsoon-POM, premonsoon-PRM) .During the study period DO values ranges from 1.762-7.23mg/l in the surface water, higher at reverine region in the PRM and lower in the MNS.Same trend also seen in the bottom water. In the surface water Fe concentration rangesfrom 0.052-3.133 µ mol/l. Higher in PRM and lower in MNS at estuarine region. Butbottom water Fe concentration higher (5.18 µ mol/l ) at estuarine region in the PRM andlower (0.063 µ mol/l ) at riverine region . Surface nitrite concentration ranges from (0.018-3.862 µ mol/l). Higher at estuarine region in PRM and lower at riverine region in POM.Same trend also seen in the bottom water. Surface Phosphate concentration ranges from0.783-20.2 µ mol/l, higher at estuarine and lower at riverine in the PRM season. But inbottom water higher in the POM and lower in PRM at riverine region. Surface silicateconcentration ranges from 13.94-147.2 µ mol/l, higher at estuarine in the POM and lowerat riverine region in the PRM period. But in bottom, water it was higher at riverine regionin POM and lower in the PRM period. The correlation pattern with certain pollutantsmainly organo –chlorine (OC) pesticides in these designed sites were also estimated .Abovementioned hydrographical parameters are well correlated with the OC pesticide residuesin the Estuarine system.

Key words: Cochin Estuary, hydrography, organic pesticides


BCO-6

Spatial and Vertical transmission Pattern of Pigments andtheir Assimilation with Nutrients in the Southern Ocean (SO)

Water Mass

Sujatha C.H, Akhil P.S, Deepulal P.M, Sini Pavithran*, Sharon B.

Noronha* and N. Anil Kumar* Department of Chemical Oceanography, CUSAT, Cochin-16, Kerala, India.

* National Centre for Antarctic and Ocean Research, Headland sada, Vasco-da-gama,

Goa 403804 India.

Thé IVth Indian Scientific Expedition to Southern Ocean cruise was carried out fromJanuary to March 2010, onboard O.R.V Sagar Nidhi. Both surface as well as sea bottomwater samples at different depths of the water column were collected from 12 stationswithin the Indian sector of the Southern Ocean [Latitude 390S to 650S and longitude 57030’E,51014’E, 53032’E & 54056’E] . Study involves spatial and vertical distribution of pigmentsand its association with nutrients in the water column. The physicochemical parameterspH, temperature, Dissolved Oxygen and Salinity have also been noted concurrently.Southern ocean water mass shows slightly alkaline character and most of the pH valueswere >8. Besides there is no gradual trend in pH values during the study period andinsignificant correlation pattern exist within the frontal regions. While oxygenconcentration are high in coastal regions of Antarctica. An exceptionally high concentrationof nitrate and phosphate was observed within the frontal regions and highest at 560S .Tremendous increase in silicate concentration was noticed towards further southernlatitude. Conspicuously no enhancement of chl-a biomass was observed in the vicinityof polar front regions . In the coastal regions of Antarctica concentration of chlorophylland other pigments was higher in surface waters . These results are useful for evaluatingthe round stock pigment and nutrient variation of Southern Ocean region and it will givea fundamental knowledge of these ecosystems.

Key words: Southern Ocean. Pigments. Nutrients. pH. Temperature .Dissolved Oxygen



BCO-7

The Distribution of REE’s along South Coast of INDIA

Deepulal. P.M, Gireesh Kumar. T.R and Sujatha C.H

Department of Chemical Oceanography, CUSAT, Cochin-16, Kerala, India

The concentration of Rare earth elements and Yttrium (REY) were measured in sedimentsfrom nine sampling location of continental shelf region of south coast of INDIA in orderto study their behaviour and distribution pattern. The REE’s are divided into LREE’s (La,Ce, Pr, Nd, Sm and Eu) and HREE’s ( Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). REE’s wereanalysed using ICP-MS. Generally these samples showed high rare earth element contentin sediments, with Y enrichments in the shale- normalized pattern (NASC). The sedimentscontain higher concentrations of LREEs than HREEs. The expected behaviour (since theREE contents of most shale and solid phases) are normally enriched in LREEs relative toHREEs. The shale normalized REEs and Y/Ho ratios additionally indicate a direct REYco-precipitation with Fe-oxyhydroxides along continental shelf and their consequentadsorption, as coating onto FeOOH surfaces. The observed variation in the Y/Ho ratiossuggest that different Y-Ho fractionation processes take place in the studied area. Tounderstand the behaviour of the shelf sediments both Ce and Eu anomalies were alsocarried out. Concurrently the statistical analysis was done using SPSS.

Keywords: continental shelf; sediments; REEs; NASC; Ce anomaly; Eu anomaly

BCO-8

Distribution of Labile Organic Carbon in the GodavariEstuary and Adjacent Ground Waters

B.S.S. Kumar, V.R.Prasad and V.V.S.S. Sarma


Carbohydrates, Amino Acids and Proteins, generally called as labile carbon, are mainlyproduced by autotrophic organisms and play an important role in biogeochemical cyclingof organic carbon in marine environments. In order to understand their distribution inestuary and interactions with ground water, concentrations of total carbohydrate (TCHO),Dissolved Free Amino Acids (DFAA), Proteins were measured at 11 stations in Godavariestuary and 22 stations in ground water along the bank of estuary at monthly interval.The estuary experienced nearly fresh water condition during the monsoon season andbrackish during dry period. Concentrations of TCHO, DFAA and Proteins weresignificantly higher in the estuarine waters than in the ground waters. The contribution


of TCHO, DFAA and proteins to total organic carbon amounted to ~10 to 60% in theestuary with significantly higher levels during peak discharge period whereas it was<20% in the ground waters with higher concentrations during peak discharge period.Low concentrations of these labile compounds in the ground water were attributed tomicrobial consumption and absence of autotrophic production. High bacterial abundanceand respiration rates in the estuary were associated with high TCHO, DFAA and proteinsdue to labile in nature and easily degradable by microbial organisms. Based on the d18Oof H

2O in the estuary and ground water suggests that significant exchange of ground

water and river occurs throughout the years and the rate of exchange increases towardsmouth of the estuary. Due to increase in the water levels in the river during peak dischargeperiod, river water penetrates to the ground water and vice versa during dry period. Ithas been noticed that labile carbon components contribution to the total organic carbonincreased from ~10% during dry period to ~20% during wet period suggesting thatsignificant amount of labile organic carbon exchanged to ground water to supportmicrobiological activities. In addition to this, ~30% of labile carbon is also transported tothe coastal Bay of Bengal during peak discharge period to fuel heterotrophic activity.

BCO-9

Variability of Trace Gases in the Godavari Estuary:Influence of Ground Water Exchange

G. Durga Rao, V.D. Rao and V.V.S.S. Sarma

National Institute of Oceanography, 176 Lawsons Bay Colony, Visakhapatnam, India

The coastal ocean is one of the most biogeochemically active zones at the surface of theEarth. Coastal ecosystems receive considerable amounts of materials from land, throughweathering of rock, exchange with ground water and injection of contaminants, andexchange these materials with the open ocean. Despite the intense biological activity, theestuaries are typical sources of trace gases such as nitrous oxide (N

2O) and methane (CH

4)

to the atmosphere. In order to understand the distribution of these gases and theircontrolling mechanisms in the Godavari estuary, systematic time series studies are beingcarried out in which data are being collected by occupying 14 stations from upstream tocoastal ocean during spring and neap tide periods. CH

4 and N

2O concentrations ranged

from 4.1 to 350 nM and from 3.4 to 25 nM, respectively, in the Godavari estuary withincreasing concentrations towards the mouth of the estuary. Both CH4 and N2Oconcentrations were low during wet period and increased by an order of magnitude duringdry period. High ammonium and low nitrate concentrations were observed during dryperiod suggesting nitrification is possible mechanism for N2O formation. In order to



examine the influence of ground water exchange of trace gases on estuarine concentrations,ground water sampling was also carried out along the bank of the river at 22 locations.High CH

4 (up to1300 nM) and N

2O (up to 180 nM) were found in groundwater and were

an order of magnitude higher than estuarine levels. The oxygen level in the ground waterwas close to suboxic to anoxic conditions suggesting that denitrification may be possiblemechanism for formation of N2O and CH4 by organic matter decomposition. Over all,both CH4 and N2O in the estuary increased towards mouth of the estuary and it isconsistent with the higher exchange rates between ground and estuarine waters, basedon d18O of H

2O suggesting that estuary is acting as a chimney to eject trace gases, which

were formed in the ground water, into the atmosphere.

BCO-10

Organic Carbon Modification in the Dam Reservoir to supportHeterotrophic Carbon Demand in the Godavari Estuary

V. R. Prasad, B.S.K. Kumar and V.V.S.S. Sarma


The Godavari is the 2nd largest river in India and contributes significantly organic carbonto the Bay of Bengal. However, the organic carbon brought by the river is modified in thedam reservoir, where water is stored for about 6 to 8 months to conserve freshwater bythe Irrigation department to be able to feed the irrigation canals and other cultural needs.Perennial heterotrophy has been observed during entire year in the estuary where 40-90% of the heterotrophic carbon demand is attributed to be supported by the externallysupplied organic carbon through river discharge. Terrestrial carbon is refractile and maynot be utilized by the bacteria. In order to examine how organic carbon is modified in thedam reservoir during storage period, time-series experiments were conducted. Nutrientsconcentrations increased by ~5 times while Chl-a increased from ~2 to 8 mg/m3 duringstorage period in the reservoir. This suggests that intense decomposition of organic matterresulting in enhanced nutrient concentrations that led to high phytoplankton production.Similarly total organic carbon was also increased from ~300 to 500 ?M during storageperiod. The labile organic carbon (carbohydrates, amino acids and proteins) concentrationswere also increased by ~4 fold during storage period due to high phytoplanktonproduction. As a result, the contribution of labile carbon to the total organic carbonamounted to ~40-50% in the dam reservoir. During peak discharge period, phytoplanktonproduction is low due to high suspended load however heterotrophic carbon demand ismainly met by high content of labile carbon in the discharge waters which was modifiedin the reservoir.


BCO-11

Stable Isotopes of Carbon and Nitrogen in Suspended Matterand Sediments from the Godavari Estuary

Ch.V. Subbaiah, S. A. Naidu and VVSS Sarma

National Institute of Oceanography (CSIR), Regional Centre, 176 Lawsons Bay Colony, Visakhapatnam

Carbon and nitrogen content and their isotopic concentrations in the suspended matterand sediments were measured at 12 stations in the Godavari estuary to examinecontribution of terrigeneous matter in the estuary. The results show significant variabilityin isotopic signatures was found over the entire length of the Godavari estuary. The meanisotopic (d13C

sed: -26.05±2.3; d13C

sus: -25.36±1.7; d15N

sed: 8.00±2.7 and d15N

sus: 6.52±0.9 ‰)

and elemental (Csed

:0.45%±0.2%; Csus

: 154.7±30 mmol l-1; Nsed

: 0.07%±0.05% and Nsus

:27.5±4mmol l-1) supports a predominantly terrigenous source. Significant enrichment in isotopicratios of d13C from upper to lower estuary in both suspended matter (-24.09 and -23.01 ‰respectively) and sedimentary (-27.00 and -27.2 ‰ respectively) indicates decrease ininfluence of terrigeneous material towards mouth of the estuary. The significant positiverelationship between d13C of suspended and sediment indicates that these two organicpools are rather coupled and a significant fraction of exchange is possible. Based on simplemixing model to our data indicate that about 46% of the suspended matter is contributedby the terrestrial origin and may support higher heterotrophic activity in the Godavariestuary.

Keywords: Stable isotopes, carbon cycling, biogeochemistry, terrigeneous organic matter,Estuary.

BCO-12

Sources of particulate Organic Carbon and Nitrogenin the Gautami Godavary Estuary

Lata Gawade and V.V.S.S.Sarma


Godavari is the largest monsoonal river in India and contributes significant amount oforganic carbon to the coastal Bay of Bengal to support heterotrophic activity. It has beennoticed that perennial existence of heterotrophy in the estuary with an average autotrophicproduction to heterotrophic respiration ratio of 0.14. It was attributed that ~40-90% of theheterotrophic carbon demand is supported by the external source of carbon and it isrelatively large during wet period when autotrophic production is limited by availability



of light due to high suspended load. Freshwater discharge brings huge amount of nutrientsto the system however the source of nutrients is unknown. In order to understand sourceof external carbon and nitrogen during discharge and wet period, content and isotopiccomposition of organic carbon and nitrogen was measured in the particulate matter (POM)during different periods. During dry period the mean ä 13C of POM in the estuary was -23.2‰ while it was -29.4‰ during wet period. The lighter d13C isotopic ratios during wetperiod suggests high terregeneous organic carbon inputs to the estuary and its influencedecreased from upstream to downstream due to dilution with marine organic matter.Similarly the average values of ä15N (‰) of suspended particulate nitrogen in estuarywas 4.41‰ during dry period and was decreased to -0.47‰ during wet period. Heavierä15N during dry period indicates in situ production was supported by regenerated nutrientsdue to heterotrophic bacterial activity as evidenced from high bacterial respiration 0.95µM C h-1 and high bacterial carbon demand 0.97µM C h-1 .Depleted d15N during peakdischarge period indicates terrigeneous sources, such as fertilizers, which was againsupported by high C:N ratio of 21 and lighter d13C. Bacterial productivity was linearlyincreased with particulate organic matter suggesting that significant amount of organicmatter decomposition in the water column. Particulate organic carbon and nitrogenfollowed Redfield ratio of 6.6 during dry period whereas it was 9.2 during wet periodindicating in situ production and terrigeneous organic matter are potential sourcesrespectively. Based on two end member mixing model, the contribution of terrigeneousorganic matter was estimated to be 80-90% during wet period while it was ~20-30% duringdry period. The magnitude of terrigeneous carbon contributed was directly proportionalto amount of discharge. This study suggests that significant amount of terregeneousorganic carbon and inorganic nitrogen enters to the estuary to support both auto andheterotrophic activity.

BCO-13

Seasonal Variation of Water Quality Parameters at Puri,East Coast of India - A Pollution Study

S.K Baliarsingh, M.K Khadanga*, & K. C SahuDepartment of Marine Sciences, Berhampur University, Orissa, India*National Institute of Ocean Technology, Palikarnai, Tamilnadu, India

In the present study the seasonal variation of DO, BOD, Salinity, Chl-a, nutrients (NO2,

NO3, PO

4, SIO

4, NH

4) and plankton diversity of coastal water were carried out. The

imperative of the study was to assess the status of water quality as the study area isunder anthropogenic influence. Municipal sewage canal of Puri discharges domestic


wastes and organic pollutants into its coastal water that results in eutrophic condition. Inthe present investigation, the premonsoon DO and BOD were recorded at 3.78 mg/l and4.01 mg/l respectively. However, it tends towards normalcy in monsoon and post monsoonseasons. High value of Chl-a concentration (18 mg/l) was recorded in postmonsoon period.Similar to the above, nutrient concentration was found to observe the same trend. TheNH

4 concentration in the water samples

reveals higher order of 28.89 mmol/l in

premonsoon, 31.22 mmol/l in monsoon and 23.99 mmol/l in post monsoon. Such valuescreate a setback for tourism industry as ammonia rich water is not suitable for recreationalactivities. That apart, it is also detrimental to nearby aqua farms and coastal fishery. Thepresent investigation also has brought about the unusual behavior of other water qualityparameters. A total of 80 species phytoplankton were documented during the entire studyperiod but the maximum diversity was recorded in post monsoon as compared topremonsoon and monsoon. The lower diversity was recorded during pre monsoon whichmay be due to low dissolved oxygen value; these are likely pointers to pollution stress.Total of 58 species of zooplankton were documented in the present piece of work. Amongstthose, some pollution indicators viz. phytoplankton species: Anabaena sp., Microcystis sp.,Oscillatoria sp. and zooplankton species: Polydora ciliata were encountered during the studyperiod indicating coastal pollution. The study recommends to take immediate necessarymeasures for sewage water treatment before it drains into the coastal water.

Keywords: Biochemical Parameters, Puri, Nutrients, Pollution

BCO-14

Dredging Impacts on the Coastal Water Quality ofDhamra, Orissa

Seoul Sangita, D. R. Satapathy, R. N. Kar and C. R. PandaEnvironment and Sustainability Department,

Institute of minerals and Materials Technology, Bhubaneswar-751 013, Odisha, India

Dhamra estuary forms an important component of the Bhitara Kanika marine sanctuaryon the northern coast of Orissa, India. The water circulation of Dhamra estuary iscontributed by two rivers namely Bramhani and Baitarani. Dhamra port, the newlyconstructed and cost-effective port on the Eastern coast of India is located at Dhamra,Orissa. It was observed that in recent years the various activities in port and harbour,basically the dredging activities affect the coastal and estuarine water quality. Consideringthe ecological importance of Dhamra region, the study was undertaken to assess thechanges if any, by evaluating the samples collected bi-monthly. The sampling stationswere selected along the stretch of river and sea interphase i.e. from port area to a distance



of 30 kilometers into the sea covering six stations including estuarine and marine zoneduring April-2009 to March-2010. The study revealed that the estuary was significantlyinfluenced by freshwater input during monsoon period. The seasonal nutrient variations(except Nitrate) exhibit higher values during monsoon season, which are related toagricultural run-off and regional anthropogenic activities respectively. The physicalparameter such as pH, salinity, conductance and chemical parameters such as TotalHardness and Total Dissolved Solid increased towards the deep marine region from theinner riverine region where as the reverse trend was observed in case of nutrients, turbidityand Total Suspended Solid. BOD value is not within the permissible limit due to abnormalmicrobial activity. The season wise observation of DO shows an inverse trend with salinityand temperature of surface water because temperature and salinity affect dissolution ofoxygen in seawater. The TSS value was high in pre monsoon period due to re-suspensionof sediment from the sea bottom as a result of current and wave action. Though the nitratevalue was higher than the other two, it was observed that the nutrient values (NO

3-, NH

3,

PO4

3- ) are within the permissible limit. It was observed that the estuarine zone of Dhamrawas significantly influenced by the anthropogenic activities and also by the fresh waterinput during monsoon period as it is a transition zone between river and oceanenvironments. The high Total Suspended Solid during dredging is a temporaryphenomenon and do not grossly modify the water quality.

BCO-15

Suspended Matter Induced Nutrient biogeochemistry in a RiverPlume Dominated Tropical Shallow Lagoon, Chilka, India

Sivaji Patra, R.S. Robin, Prdipta.R.Muduli, K.Vishnu Vardhan,U.S.Panda andB.R. Subramanian

ICMAM Project Directorate, Ministry of Earth Sciences, NIOT Campus, Pallikaranai, Chennai 600 100, India

Coastal river plumes signify one of the final stages of material transport, across the landsea interference. Most studies however have focused on the behavior of small sized riverplume of coastal and shelf waters, whereas large river plumes and its role onbiogeochemical cycles have been neglected. This present study address the behavior anddistribution of suspended particulate matter (SPM), dissolved inorganic nutrient (DIN,DIP, DSi) and chlorophyll a (Chl.a) in Chilika lagoon induced by Mahanadi river plume.Resuspension of SPM was frequently observed within the lagoon with a significantcorrelation with water quality parameters nutrients. The mean SPM concentration wasfound to be 47.76 ± 25.57 mg L-1 and 79.17 ± 96.82 mg L-1 during Premonsoon andpostmonsoon respectively whereas during monsoon it reached up to 239.73 ± 345 mg L-


1.The DIN (NO3+NO

2+NH

4) concentrations was found highest during Monsoon (14.54 ±

7.56 ìM) followed by Postmonsoon (7.86 ± 7.29 ìM) and Premonsoon (3.04 ± 2.03 ìM). Theconcentration of dissolved inorganic silicate (DSi) also found high (144.59 ± 47.15 ìM)during the MN with values >200 ìM along the northern sector of the lagoon. In contrary,a substantial reduction in silicate (<20 ìM) could be noticed during the PRM. The meanN:P ratios observed to be 9.28 ± 6.09, 30.02 ± 17.53 and 6.12 ± 4.93 during Premonsoon,Monsoon and Postmonsoon respectively. From this ratio, it is evident that duringPremonsoon and Postmonsoon lagoon is nitrogen limiting, whereas, MN shows phosphateas limiting with surplus nitrogen influx. Horizontal negative gradient of SPM and nutrientfrom the northern sector towards the southern sector depict a strong influence of Mahanadiriver plume on the biogeochemistry and nutrient distribution in the lagoon. Chl.a a recordssuggested that only nutrients have the stimulating effect on the water column productivityin all the seasons. On the contrary, inhibitory influence (light limitation) by the SPM overphytoplankton growth was found negligible which become weaker from the northerntowards the southern sector of the lagoon. Imported SPM may play a decisive role inregulating the water columns N/P ratio by desorption of nutrients to the lagoon water ata seasonal basis.

Key words: Lagoon; suspended particulate matter; nutrients; chlorophyll; river plume



ABSTRACTS

THEME-11 COASTAL PROCESSES & COASTAL ZONEMANAGEMENT


CPCZM-1

Hydrodynamic and dispersion modeling of coastal tropicallagoon: a case study in Chilika lagoon

Uma Sankar Panda, V. Ranga Rao, B. R. Subramanian, R. N. Samal* and

M. M. Mohanty*

ICMAM-PD, Ministry of Earth Sciences, NIOT Campus, Chennai*Chilika Development Authority, Bhubaneswar - 751014, India

Numerical models act as an excellent tool to obtain the right measures and applications torestore the environments undergoing rapid degrading situations. In this study, modeling efforthas been made to the Chilika lagoon, the Asia’s largest brackish water lagoon, which isundergoing rapid ecological changes in recent years. Water level and circulation was simulated,using a hydrodynamic model (HD). Driving forces such as tide, wind, fresh water inflows andmajor calibration factors like the bed resistance coefficient (Manning number=32 m1/3/s), theeddy viscosity coefficient (Smagorinsky formulation) and the wind friction coefficient wereconsidered for HD model. In the advection/dispersion (AD) model, heat exchange coefficientsin the Dalton’s law and Angstrom’s law equations for temperature simulation and the dispersioncoefficient for salinity simulation are the major calibration factors. Both HD and AD modelshave been calibrated and validated with field measurements. Several sensitivity analyses havebeen investigated. The result shows that the southern sector found to be more stable in terms ofhydrodynamics. The water level measurements with good agreement as the RMS is betweenmeasured and predicted water levels didn’t exceed the 8% of the data range during validationand the model skill equal to 0.85 near inlet, while it decreases in the main body of the lagoon.The simulated daily water temperature variations were well correlated with the data gainedduring the field observations. The measured and the computed time series present a modelskill equal to 0.82 near Inlet, decreases in the main body. The salinity variation near the inletshows stratification while it is homogenous throughout the lagoon.

CPCZM-2

Flux measurements at the Cochin Harbour Inlet usingAcoustic Doppler Profiler

C. Revichandran, K.R. Muraleedharan, V.K. Jineesh, Vijay John Gerson*,

Shivaprasad Amaravayal M. Rafeeq

National Institute of Oceanography, Regional Centre, Dr.Salim Ali Road, Kochi-18

*Department of Chemistry, St. Alberts College Kochi-18

Cochin estuarine system (Vembanad lake and surrounding islands) occupies nearly320Km2 of area with six rivers flowing in to it. Seasonal river discharge and the tides



determine the hydrodynamics and biogeochemistry of the estuarine system. Tides in theestuary are semidiurnal with periodicity of 12.42 hrs. Annual river discharge in to the systemform the six rivers are estimate to be 2000M.m3 . These high fresh water empties into the seathrough Cochin harbour inlet and partly through Munambam bar mouth. Cochin port trusthas recently embarked on many major constructional activities, like Vallarpadam ContainerTranshipment terminal, marina and building of roads and bridges across the back waters.Deeping of the approach channel to facilitate bigger ships to berth at Vallarpadam terminalhas altered the flow filed in the harbour region significantly. Periodic measurement of riverflux across the harbour inlet is essential to quantify the nutrient and sediment transportand to assess changes in the flow due to anthropogenic activites. Acoustic Doppler CurrentProfiler (ADCP) is increasingly used for velocity and discharge measurements across river/ estuarine channels. This paper presents the advantage and efficacy of a moving boat ADP(Sontek, ADP ,1500 Mhz) for the measurement of discharge in a distinctly two layer flowfield. For the computation of residual fluxes measurements were carried out over twosemi-diurnal tidal cycles at an Interval of I hour during spring and neap tide. Residualfluxes were 15.09 M.m3 and 13.20 M.m3 during Neap and Spring respectively. The excessfluxes during the neap phase eventually increase the vertical salinity stratificationconsiderably as evidenced in the vertical salinity sections.

CPCZM-3

Impact of mining on the stability of a placer mining beach1K.Rajith, *N.P. Kurian and *V.R. Shamji

Naval Physical & Oceanographic Laboratory, Kochi 682022*Centre for Earth Science Studies, Thiruvananthapuram 695031

The Chavara coast of southwest coast of India is fraught with environmental issues suchas coastal erosion and mining. The coast is well known for the rich heavy mineral deposits,which are being mined commercially. A detailed study was conducted to understand therole of mining on erosion process along the coast. The study involved extensive fieldmeasurements and numerical modelling. Based on the results it was found that the coastunder study is an open system with considerable inputs by the longshore as well as thecross-shore transports. It was deduced that the impact of mining would not significantlyaffect beach when the mining was within an optimum level equivalent to the quantum ofsand replenished by the natural processes. If the quantum of mining exceeds this level, itcould cause local impacts on the beach as well as in the innershelf area.

The mining scenario changed in the area of study since 2001. While the Indian Rare EarthsLtd. was the major player in the area till 2001, the Kerala Minerals and Metals Ltd. (KMML),


expanded its mining operations in a major way starting from 2001. The combined miningby both these firms constituted a quantity much more than the annual replenishment. Toverify the possible impact of this huge quantum of mining on the beach morphology,beach profile measurements were continued till 2004 at selected stations. It was seen thatwhile station located in Kovilthottam mining site maintained its dynamic equilibrium,station located in Vellanathuruthu mining site showed cumulative loss of material showingthe imbalance. It is pertinent to note that the beach adjoining the station located inVellanathuruthu mining site was the intake area of KMML too. The result shows that thecombined mining by KMML and IREL has offset the dynamic equilibrium in beach volumechanges seen till 2001 at VMS 7 and it supports the hypothesis that any intake more thanthe annual replenishment could have serious consequences on the beach.

CPCZM-4

Acoustic Doppler Velocimeter Measurements of Surf ZoneCurrents along Visakhapatnam-gangavaram Coast

V. Ranga Rao, S.V.V., Arun kumar*, K.V.S.R.Prasad*, Ch Venkata Ramu*,

K.V.K.R.K Patnaik* and M. ManikandanICMAM-PD, Ministry of Earth Sciences, NIOT Campus, Chennai-600100

*Dept of Meteorology and Oceanography, Andhra University, Visakhapatnam-530 003

Surf zone currents play a crucial role in nearshore sediment transport pattern along anycoast. Surf zone current measurement is a challenging task because breaking waves andstrong currents exert powerful forces on instruments.. For this study we measured hourlyvariations of littoral currents by mooring an Acoustic Doppler Velocimeter (ADV) in themid-surf zone for two tidal cycles each at 5 stations during June 2009 along 25km coastalstretch encompassing Visakhapatnam coast. This instrument records the cross-shore (Vx),alongshore (Vy) and vertical (Vz) components of the currents following Doppler shiftprinciple of acoustic sound signals. This insitu data has many applications in CoastalEngineering for estimating the strength of longshore currents, in identification of ripcurrents, and in assessing the littoral sediment transport. Surf zone currents are mainlygenerated due to the energy released (radiation stress) after the waves break at theshoreline i.e. they are wave-induced. Apart from the waves, tides are observed to playvery crucial role in modifying the strength of the currents particularly the cross-shore(Vx) currents. The strength of Vx currents is observed to be increasing from peak low tide(slack) hours and attaining maximum within two-three hours. Therefore, it is evidentfrom our observations that tidal stage is modulating the nearshore currents. The strengthof the Vy currents is varying accordingly with the height of the offshore waves. Thealongshore currents are weak within a range of 0.1-0.2 cm/s and are undulating along the



coast. The cross-shore currents are relatively stronger (0.3-0.5 m/s) and are directedoffshore. Stronger cross-shore currents were recorded at RK Beach and Yarada; indicatingthat these two beaches are vulnerable for rip current formation. In a sheltered bay atJonnalakonda, both the currents are observed to be very weak.

CPCZM-5

Intra-annual Varibility of Wave Characteristics at aNearshore Location in West Coast of India

K. Jossia Joseph and B. K. Jena

National Institute of Ocean Technology, Pallikaranai, Chennai, India-600100.

The wave characteristics and its variability are of great significance in offshore and nearshore engineering. Long term time series data is required to identify the characteristics ofthe waves at the area of interest. The wave data collected off Vijayadurg at 17m waterdepth during October 2006 to September 2007 at an interval of one hour is utilised in thisstudy to delineate the intra-annual variability at this location. The significant wave heightis less than 1m with an average wave period of 6s except during southwest monsoon season.The significant wave height ranges between 1.5m to 5m during June to September whichindicates the rough sea state during the south west monsoon. The mean wave direction ispredominantly westerly and varies between west southwesterly and west northwesterlywhereas the swell waves remain steady southwesterly. The energy in the swell componentis in general less than that of sea component except during southwest monsoon. The waveenergy in the swell component is higher than the sea component and exhibits the samedirection as that of mean wave direction during the southwest monsoon. The sea state atthis location is greatly modified by the presence of strong swells during southwest monsoon.

The analysis of wave spectra exhibits the dominance of double peaks over single peaks atthis location. The wave spectra exhibit mainly single peak during southwest monsoon seasonand double peaks for rest of the year. Multiple peaks in the spectra are also observed butwith lesser percentage of occurrence and is not specified to a season. The most of the majorpeak in the double peaked spectra is observed in the sea component with spectral peakbetween 4.5s and 7s. The spectral peak in the swell component varies from 11s to 17s andmostly exhibits the secondary peak in the spectra. The spectra with equal peaks in sea andswell component are also observed but with lesser frequency. Similarly there are a fewoccurrences of swell dominated double peaked spectra. The wave spectra changes to singlepeak by the end of May and remains till the end of September with spectral peak in theswell component. A slow transition in spectral peak is observed during southwest monsoonfrom 14s to 9s. The wave characteristics at this location reveal the dominance of swell wavesand double peaked spectra which requires special attention in the design of structures.


CPCZM-6

Assessment Of Shoreline Changes Of Chennai, Tamil NaduUsing Gis (3D Vectorisation) and Digital Image

Processing Techniques

R. S. Kankara, B. Rajan*, S. Chenthamil Selvan*, V. Ram Mohan*

Integrated Coastal and Marine area Management Project Directorate, Ministry of Earth Sciences,Government of India, Pallikaranai – 600 100, India

*Department of Geology, University of Madras, Maraimalai Valagam, Chennai – 600 025, India

About 23% of the Indian coastline is affect due to coastal erosion and coastal protectionworks have been carried out at various locations along the coast. Shoreline changes areone of the serious problems in several pockets along Indian coast. The coastline has beensubjected to several geo-morphological changes due to natural processes and manmadeactivities and the shoreline evolution is of major concern for coastal communities. Theshoreline retreat leads to loss of beaches and consequently to set back of the coastlinethat threatens the coastal communities. The changes in shoreline s are generally seasonaldue to changes in wind, waves, currents, and sediment transport. Further, the additionalchanges occur when perturbations are introduced by anthropogenic factors/activities ofcoastal zone. The information about shoreline changes is the basic requirements for allthe coastal infrastructure projects and sustainable coastal zone management. Shorelinechanges are dynamic in nature and demand constant monitoring. The Remote Sensing &GIS are very useful to understand the long-term process of shoreline changes. In thispaper, attempt as been made to use these techniques to analysis the long term shorelinechanges along Chennai coast. The study was conducted for 15 km long coastal stretchbetween Thiruvottiyur to Thiruvanmiyur covering Marina and Besant Nagar touristbeaches to study shoreline changes occurred in last 4 decade. The details of satellite dataand field data used in the study were given in the following table.

S.NO YEAR OF DATA TYPE OF DATA’S RESOLUTION

1 1972 LANDSAT (MSS)–REMOTE SENSING 57M

2 1991 LANDSAT (TM)–REMOTE SENSING 28.5M

3 2000 LANDSAT (ETM)–REMOTE SENSING 28.5M

4 2007 CARTOSAT-1–REMOTE SENSING 2.5M

5 2008 RTK–GPS–FIELD SURVEY <5CM (ACCURACY)

6 2007, 2011 ARC-PAD GPS –FIELD SURVEY <3M (ACCURACY)



The remote sensing datasets were geo-referenced in image processing software (ERDAS)by Polynomial 2nd order using Universal Transverse Mercator (UTM) projections and WorldGeographic System (WGS 1984) datum. Landsat images were used, to extract the shorelineautomatically by image processing techniques. 5th band of Landsat image was classifiedinto 2 classes and shoreline was automatically extracted from the classified images.Cartosat image is overlaid on Cartosat DEM for manual 3D vectorisation. The 3D view ofCartosat DEM was generated to distinguish the shoreline. The extracted shoreline wasverified from field survey (GPS data). Finally, the periodical shoreline changes for 39years were analyzed for the entire coastal stretch using DSAS (Digital Shoreline AnalysisSystem) statistical stand-alone tool. The results confirm that the shoreline in the northernregion of the port was eroded at the rate of -4.2m/y and southern part of the study area(MARINA) is extending EASTWARD (Seaside) with a rate of 1.4m/yr for past 39 years.However, after construction of groins along the Royapuram region, the erosion rate wasmarginally reduced and small beaches formation is noticed around few groins. TheCARTOSAT data was found very useful for Shoreline Change Studies.

CPCZM-7

Management of Shoreline Morphological Changesdue to Breakwater Construction along a Stable Coast

V.Noujas1, K.O.Badarees1, N.R.Ajeesh2, L.Sheela Nair1,

T.S.S.Hameed1 and K.V.Thomas1

1 Centre for Earth Science Studies, Trivandrum2 National Institute of Technology Karnataka, Surathkal

[email protected]

Kerala coast is considered to be one among the highly eroding coastal sectors and theimpact of erosion is the highest due to the thickly populated narrow coastal belt. Themajor factors influencing shore stability along the Kerala coast are construction of harbourbreakwaters, coastal protection structures, sand mining and occurrence or disappearanceof mud banks. Various researchers have studied the scenario of shoreline changes alongthis coast with respect to the above factors at different locations. In the present study, theprocesses of shoreline morphological changes along a stable, high energy coast areanalyzed using numerical models to propose management options to tackle themorphological modifications.

The coastal stretch from Veli to Varkala has two identifiable sediment cells separated bythe Muthalapozhi inlet with harbour breakers on either side of the inlet. The constructionof breakwaters has caused substantial erosion immediately north of the inlet and beach


build up south of the inlet. The harbour mouth gets blocked due to deposition of beachsand, virtually making the harbour unusable. Shoreline changes, near shore processesand beach characteristics along this sector are studied through extensive field observations.These observations are used to calibrate and validate sediment transport and shorelinechange models for this coast.

Sediment transport and shoreline changes are simulated using different modules ofLITPACK model. Monsoon erosion is characterized by events of short period steep waves,which occur as repeated events of few days during monsoon season, transforming thenormal profile of pre-monsoon to storm profile with a bar-trough configuration. The stormprofile moves onshore-offshore depending on the breaks in the monsoon. The beachbuilding period following monsoon has longer period swells bringing back the beachsediment, which is a long drawn process over a period of few months. Hence the behaviorof coast during monsoon is simulated using LITPROF module of LITPACK. The processduring beach building period has been simulated using shoreline evolution modelLITLINE. The calibration of the model is done with field observations. It is found thatbeach sediments get deposited on south side of the breakwater and bypassed sedimentgets deposited at the inlet mouth. The validated model is used to simulate the processeswith different designs and a groin field of smaller groins of length comparable with thesurf zone width during beach building period, about 600 m south of the breakwater, hasbeen found best suited to control the choking of harbour mouth due to sedimentdeposition.

CPCZM-8

Investigation of Geomorphic Processes on Mulky - PavanjeRivermouth, West Coast of India

Gumageri Nagaraj and Dwarakish G S

National Institute of Technology Karnataka Surathkal

Coastal regions, in particular the regions around the rivermouths are highly complexand dynamic environment; undergo significant spatial changes in a relatively short spanof time. These regions never ever maintain a morphological equilibrium and create crucialmanagement problems. In the current study, Mulky - Pavanje rivermouth, central westcoast of India is selected to understand the geomorphic processes occurring in and aroundthe rivermouth. Textural characteristics of the surficial sediments were studied on amonthly basis to understand the geomorphic response of the region, by selecting eightlocations on either side of the rivermouth for a period one year, from September 2009 toAugust 2010. Sediments have been investigated for their textural characteristics; mean



grain size, sorting and skewness. Textural analyses indicated that foreshore sedimentsnear the rivermouth during pre-monsoon were dominated by fine grained, well sortedand positively skewed, whereas away from the rivermouth dominated by coarse grained,well to moderately well sorted and negatively skewed sediments. However during themonsoon the foreshore was dominated by coarse grained at all locations and during thepost-monsoon sediments changed to medium to fine grained, well to moderately wellsorted and dominantly symmetrical positively skewed sediments. This indicates a distinctseasonal variation in textural parameters at all locations and the variations are highlysignificant from one location to other.

CPCZM-9

Enhanced stratification during Neap Tide of Godavari Estuary

B. Sridevi, V.V.S.S. Sarma and T.V. Ramana Murty

National Institute of Oceanography (CSIR), Regional Centre, Visakhapatnam.

Godavari River is the second largest river in India which originates in the Western Ghatsnear Nasik at an altitude of about 1620 m and flows eastwards through Godavari grabento join the Bay of Bengal covering a distance of 1480 km. At confluence it forms a hugedelta region. The daily variations in fresh water discharge are controlled by a century old“Low Dam” at Dowleiswaram where Godavari splits into Gowthami-Godavari andVasista-Godavari, which is about 60 km from upstream (Kotipalli). In order to examinethe desertification-stratification variability from spring to neap tide, hourly CTD datawas collected along the estuary at 5 locations and currents data at middle of the Gowthami-Godavari estuary (Yanam) at an interval of 10 min for 7 days during peak discharge(September, 2008; wet period) and 10 days during no discharge periods (February, 2009;dry period).

The mean river discharge during wet period was 27560 m3 s-1. The salinity distribution inthe estuary suggests that saline water intrudes into the estuary up to about 40 km fromthe mouth during dry season, which was about 25 km during wet period. The flow alongthe axis of the estuary is the dominant feature of the circulation and there is a weak cross-shore flow. The zonal velocities are nearly 10 times higher during September than Februarywhich suggests the existence of two layer structure. The brunt-vaisala-frequency, shearand richardson’s are ranging from 20 to 25 (radian/sec)2, 2.6 to 4.4 (1/sec)2 and 5.59 to 9.17during wet and 1.5 x10-3 to 4 x10-4 (radian/sec)2, 0.24 – 2.28 (1/sec)2 and 6.2x10-4 – 19.6x10-

4 during dry period respectively. Computed shear and brunt-vaisala-frequencies wereincreased during neap than spring tide with decrease in richardson’s number suggestingthat stratification was increased during neap than spring tide. The values of richardson


and Froude numbers suggest that estuary is in well-mixed and salt-wedge during dryand wet periods respectively. The presence of sand dune affected the flow direction fromspring to neap tide and strengthening the cross-shore flow.

Key words: Gautami-Godavari, spring-neap tides, brunt-vaisala-frequency, richardson’snumber, Froude number

CPCZM-10

Role of bottom friction in a tidal estuary under combinedaction of waves and currents and its validation

Chitra Arora and Prasad K. Bhaskaran


Waves propagating into near-shore coastal environments are subjected to energytransformation where bottom friction plays a dominant role in the redistribution processof energy density spectrum. The extent of wave energy dissipation is governed byconditions of the sea-bottom. The state-of-art wave models assume resistance law frombottom interaction due to sandy beds. The effects due to bottom friction in a heterogeneousbottom environment can vary due to changing water levels. In a tidal dominated estuary,change of water level associated with reversing currents are expected which can lead totime dependent change of water depth at any given location. Hence, the changing waterlevel has direct implications on associated bottom friction arising due to waves andcurrents. The state-of-art wave models like SWAN (Simulating Waves Near-shore) usethree different formulations for bottom friction viz; JONSWAP, Collins and Madsen.Though these three formulations are semi-empirical in nature and based on laboratoryand field studies, its implementation in SWAN is based on time independent constantvalue for any given study area. This can lead to under/over-estimation of wave energyfor a given water depth by choosing any of the three appropriate bottom frictionformulation. The practical implications being gross approximation in studies relevant tothe estimation of sediment transport and sediment budget analysis. In view of this thereis an apparent need to develop a time varying bottom friction formulation that takes intoaccount the combined action of waves and currents and associated shear in a tidaldominated estuary. The present work reports on development of a new resistanceformulation for bottom friction and its implementation in SWAN model which takes intoaccount the combination of waves and currents prevalent in an estuarine environment.The study region chosen was the Hooghly estuary located in head Bay region in the Bayof Bengal. The spatial distribution and characteristics of bottom sediments in this estuarywere obtained based on reports of IRS-1A measurements. The setup of SWAN runs



comprises GEN3 physics of Komen with Triad wave-wave interaction and turning on thewhite capping dissipation. Four different case studies were made each with differentbottom frictional formulations. The comparison of significant wave heights with theexisting and developed bottom friction formulations were then investigated with ENVISATsatellite based measurement in the Hooghly estuary. The results suggests that the newformulation to be in close agreement with measurements and hence its application forwind-wave modelling studies in coastal waters.

CPCZM-11

Prospects for Developing a Minor Port Facility at Betul, Goa

Thomas Mathai, Satish Kumar, K.N. Rajarama, P. Praveen Kumar and

M. Suresh Chandran

Marine and Coastal Surveys Division, Geological Survey of India

Escalating industrial development and localization of special economic zones in theKonkan sector warrants the enhancement of infrastructural facilities especially in regardto shipping and cargo movement. Heavy shipping traffic has totally congested both theports of Goa and Karwar. The development potential for setting up a minor satellite portat Betul, a coastal village with its small fishing harbour, is immense. Located at the mouthof the Sal River, the Betul area is strategically located between Goa and Karwar which, ifdeveloped into a minor port, could help divert some of the medium to small vessels andhelp ease the congestion. A ruined concrete jetty projecting for about a mile from theshore, east north east of Moliem point, testifies to a probable pre-existent port that hadsilted up. Sal River is presently navigable from the sea only by country boats and fishingtrawlers during high tide; the thick and extensive sand bar almost sealing the river mouthis a big impediment to even small-scale shipping and fishing activities in this sector. Ashort and narrow wharf on the southern side of the river mouth was being used by smallcraft to transport iron ore to barges at anchor but now the activity is dormant, being dulyhampered by the siltation at the river mouth. Strategies presently being adopted fordredging out deeper parts of the Sal river outflow sector have apparently not broughtabout any appreciable deepening to facilitate any shipping traffic and at the most canonly afford short-term benefits. The Marine and Coastal Surveys Division of GeologicalSurvey of India, initiated preliminary, integrated geological, geotechnical and geophysicalsurveys off Betul for making an appraisal of the developmental possibilities of setting upa minor port in this sector. Detailed surveys were carried out for preparation of abathymetric map of the area. Shallow seismic and Magnetic surveys formed part of thegeophysical underway surveys besides scanning the seafloor in the proposed channelalignment sector. The studies also included collection of sediment cores to evaluate the


sub-seabed sediment package and visualize the seabed sediment distribution.Geotechnical analysis of the sediments helped to prepare a geotechnical map of the area.Basic data on pollution was also generated from seawater samples besides recordingenvironmental parameters in order to establish background values for post-developmentcomparison. Very well developed proximal beaches at Canaguinim Bay and Rama Bayhave proven to be excellent tourist attractions. The surveys reveal that both bays couldprovide excellent anchorages for Cruise liners and pleasure craft; the Rama Bay, inparticular, is well protected on the south by a huge natural promontory in the form of agabbroic ridge jutting out into the sea. Dual utility of this sector in the backdrop ofenhanced impetus to eco-tourism and the imminent need to cater to the pleasure sailingcrafts that frequent this area with its high tourist potential could thus be well addressed.The overall assessment therefore ascribes an immense potential for the establishmentand development of a minor port and related facilities in the Betul sector.



LM-001Dr N.BAHULAYANVANCHIYIL HOUSEVALATHUNGAL (PO)ERAVIPURAMQUILON -18KERALA

LM-002REGIONAL CENTRE,NATIONAL INSTITUE OF OCEANOGRAPHY,SALIM ALI ROAD,KOCHI 18, KERALAMOB:9447233286EMAIL:[email protected]

LM-003Sri. V. CHANDER7C, NJK SIVAMLAYAM ROAD KOCHI-682011PH:0484 -2362615EMAIL:[email protected]

LM-004Dr. C.V.K PRASADA RAON.P.O.L, THRIKKAKARA P.O,KOCHI-682021MOB:9446594250EMAIL:[email protected]

LM-005Dr. RAO VSN TATVARTICASTLECENTRE FOR ADVANCEMENT OF SCIENCE8-43-31, 3 CROSS ROADVIDHYANAGARANDHRA UNIVERSITY POVISHAKAPATNAM- 530003EMAIL: [email protected]

LM-006Dr. SHYAM KISHORE SRIVASTAVAN.P.O.L, THRIKKAKARA PO,KOCHI-682021MOB: 9447166315EMAIL: [email protected]

LIST OF OSI LIFE MEMBERS

LM-007Sri. A DHURKADASN.P.O.L, THRIKKAKARA P.O,KOCHI-682021PH:0484 2422947EMAIL:[email protected]

LM-008Dr. J SWAINTARANG NIVASIX/639- G LINKVALLEY,LIVRA-11, KUSUMAGIRIPO.KAKKANAD, KOCHI-682030PH:0484 2424911EMAIL:[email protected]

LM-009Dr. MP AJAIKUMARN.P.O.L,THRIKKAKARA P.O,KOCHI-682021PH:0484 2424911

LM-010Dr. PV HAREESH KUMARN.P.O.L,THRIKKAKARA P.O,KOCHI-682021PH:0484 2423009EMAIL:[email protected]

LM-011Sri. ANAND P.N.P.O.L,THRIKKAKARA P.O,KOCHI-682021MOB: 9846314883EMAIL:[email protected]

LM-012Dr. PRADEEP KUMAR T.H. NO. XII/ 170‘THE PALMS’VAZHAKKALA, KAKKANAD PO.KOCHI-682030PH:0484 2424911EMAIL:[email protected]

LM-013Sri. R.V SUBBA RAON.P.O.L,THRIKKAKARA P.O,KOCHI-682021PH:0484 2424911EMAIL:[email protected]


LM-014Dr. P. A MAHESWARANN.P.O.L,THRIKKAKARA P.O,KOCHI-682021MOB:9846651296EMAIL:[email protected]

LM-015Sri. ANIL KUMAR K.N.P.O.L, THRIKKAKARA PO,KOCHI-682021MOB: 09846203991EMAIL:[email protected]

LM-016Dr. N MOHAN KUMARN.P.O.L, THRIKKAKARA P.O,KOCHI-682021PH:0484 244911

LM-017Sri. SANJEEV NAITHANIN.P.O.L, THRIKKAKARA P.O,KOCHI-682021PH:0484 2424911

LM-018Dr. R.S RAJESHGEOPHYSICS DEPTIIT, KHARAGPURKHARAGPUR-721302EMAIL:[email protected]

LM-019Sri. CHANCHAL DE,G-FASTDRDO Hqrs,New Delhi

LM-020Dr. BASIL MATHEWN.P.O.L, THRIKKAKARA P.O,KOCHI-682021PH:0484 2422590

LM-021Dr. K.P.B MOOSADN.P.O.L, THRIKKAKARA P.O,KOCHI-682021MOB: 9446401168EMAIL: [email protected]

LM-022Sri. RAMESH P PAICC 8/15711APOOMARAM HOUSEALATHUKUTTY ROADKOCHI-682002MOB: 9446382544EMAIL: [email protected]

LM-023Dr K.V SANIL KUMARN.P.O.L, THRIKKAKARA P.O,KOCHI-682021MOB: 9447100166EMAIL: [email protected]

LM-024Dr. M.R RAMESH KUMARP.O.D,NIO DONA PAULA, GOA-4030041MOB: 9423056323EMAIL: [email protected]

LM-025Dr. DODLA VENKATA BHASKARRAODEPT. OF METEOROLOGY ANDOCEANOGRAPHYANDHRA UNIVERSITYVISHAKAPATNAM-53003 MOB: 9440592410EMAIL:[email protected]

LM-026Dr. A S UNNIKRISHNANN.I.O, DONA PAULA,GOA-403004PH: 08322450311EMAIL: [email protected]

LM-027Dr. D.D EBENEZERN.P.O.L,THRIKKAKARA PO,KOCHI-682021EMAIL: [email protected]

LM-028Sri M GOPAKUMARN.P.O.L,THRIKKAKARA P.O,KOCHI-682021PH:0484 2424911



LM-029

Sri SUBASH CHANDRA BOSE M.R

NO. XXII/ 229, HARIGOVINDAM

14TH CROSS ROAD

MAVELINAGAR

CUSAT PO

KOCHI-682022

EMAIL:[email protected]

LM-030

Dr R RAMESH

N.P.O.L,

THRIKKAKARA P.O,

KOCHI-682021

PH:0484 2424911

LM-031

Sri N SADHISH KUMAR

KAILAS HOUSE

KARINAKKAD

BEHIND VIMALA HOSTEL

THRIKKAKARA PO,

KOCHI-21

PH:0484 2424911

LM-032

Sri VIJAYAN PILLAI M. K.

N.P.O.L, THRIKKAKARA P.O,

KOCHI-682021

MOB: 9447237090

EMAIL: [email protected]

LM-033

Sri G.S RADHAKRISHNAN NAIR

MIG-50 SOUPARNIKA

SURABHI NAGAR

KAKKANAD

KOCHI-682030

MOB: 9446740168


LM-034

Sri D. THOMAS

TYPE IV/34, SAGAR COMPLEX

NPOL QUARTERS

THRIKKAKARA PO

KOCHI-682021

MOB: 9447510362


LM-035Sri VIBIN M.VN.P.O.L, THRIKKAKARA PO,KOCHI-682021PH: 0484 2424911

LM-036Sri M RAJENDRAN76, TYPE III, NPOL QUARTERSTHRIKKAKARAKOCHI-682021MOB:9447475597EMAIL:[email protected]

LM-037Dr. M HARIKRISHNANN.P.O.L, THRIKKAKARA P.O,KOCHI-682021MOB: 9447986162

LM-038Sri. M M MUNIN.P.O.L, THRIKKAKARA PO,KOCHI-682021PH:0484-2572624EMAIL:[email protected]

LM-039Sri. JINEESH GEORGEN.P.O.L, THRIKKAKARA PO,KOCHI-682021MOB: 9447627027

LM-040Sri. R.M R VISHNU BHATLAH.No. 2-2-22/3/203FLAT.NO.203, ELENTA SAIMITRA APTS.DD COLONY, BAGH AMBERPET (PO)HYDERABAD- 500 013PH: 040-27401246EMAIL: [email protected]

LM-041Dr. M.R SANTHA DEVIKOCHUPARAMBILWEST END ENCLAVENGO FLAT ROAD, THRIKKAKARAKOCHI-682021MOB: 9895645696EMAIL: [email protected]


LM-042

Dr ABHIJIT SARKAR

OCEAN SCIENCES DIVISION MOG

SPACE APPLICATIONS CENTRE,

AHMEDABAD-380015

MOB: 9426301523


LM-043

Dr. S K BASU

OCEAN SCIENCES DIVISION MOG

SPACE APPLICATIONS CENTRE,

AHMEDABAD-380015

PH: 0792 6916115


LM-044

Dr. PRANAV SURESH DESAI

A-46 SHREE RANG VILLA

VASTRAPUR,

NEAR RJT COLLEGE

AHMEDABAD-380015

MOB: 9824006712

LM-045

Dr. A UNNIKRISHNAN

N.P.O.L, THRIKKAKARA P.O,

KOCHI-682021

PH: 0484 2428067

LM-046

Dr. K.V.S.R PRASAD

DEPT. OF METEOROLOGY AND

OCEANOGRAPHY

ANDHRA UNIVERSITY

VISHAKAPATNAM-53003

MOB: 9849798068


LM-047

Dr. Ing E.h. Dr. V SUNDAR

DEPT OF OCEAN ENGINEERING IIT

MADRAS

CHENNAI-600036

MOB: 9444049629


LM-048

Dr. R SUNDARAVADIVELU


MADRAS

CHENNAI-600036

MOB: 9444008620


LM-049

Dr. V ANANTHA SUBRAMANIAN


MADRAS

CHENNAI-600036

MOB: 9444406812


LM-050

Dr. S A SANNASIRAJ


MADRAS

CHENNAI-600036

MOB: 9444032005


LM-051

Dr .K MURALI


MADRAS

CHENNAI-600036

MOB: 9444008627


LM-052

Dr. S NALLAYARASU


MADRAS

CHENNAI-600036

MOB: 9840742720


LM-053

Dr. P KRISHNANKUTTY


MADRAS

CHENNAI-600036

PH: 0442 2574820




LM-054Dr. R PANNEER SELVAMDEPT OF OCEAN ENGINEERING IITMADRASCHENNAI-600036MOB: 9884732776EMAIL: [email protected]

LM-055Dr. A D RAOCENTER FOR ATMOSPHERIC SCIENCESIIT –DELHIHOUZKHASNEW DELHI-110016MOB: 09868773650EMAIL: [email protected]

LM-056Dr. P V JOSEPHDEPT OF ATMOSPHERIC SCIENCESCUSATFINE ARTS AVENUEKOCHI-682016MOB: 9847625788EMAIL: [email protected]

LM-057Dr. R SAJEEVSAUPARNIKAYMJ ROADNORTH JANATHAPALARIVATTOMKOCHI_682025EMAIL: [email protected]

LM-058Dr. THOMAS MATHEWA-24, CHANDOLODIA KAILASNAGARCO. OP. HOUSING SOCIETY LTDDr. SHILPA SHILPA BHUVANCHANDOLODIAAHMADABAD – 382481MOB: 09427069018EMAIL:[email protected]

LM-059Dr A C NARAYANAPROFESSORCENTRE FOR EARTH SPACE SCIENCEUNIVERSITY OF HYDRABAD

CENTRAL UNIVERSITY P.OGOCHIBOWLIHYDRABAD - 500046MOB: 99896 25346EMAIL: [email protected]

LM-060Dr. DEBABRATA SENDEPT OF OCEAN ENGINEERING & NAVALARCHITECTUREIIT,KHARAGPUR-721302MOB: 9434017359EMAIL: [email protected]

LM-061Dr. C K RAJAN RAJAGEETAMMATHAR NAGARKOCHI-682033MOB: 9847968699EMAIL: [email protected]

LM-062Dr. RAMA GOVINADARAJANJ NEHRU CENTRE FOR ADVANCEDSCIENTIFIC RESEARCHJAKKUR. BANGLORE-560064PH:0802 2082828EMAIL: [email protected]

LM-063Dr. K.R SRINIVASJ NEHRU CENTRE FORADVANCEDSCIENTIFIC RESEARCHJAKKUR, BANGLORE-560064PH: 080 22082836EMAIL: [email protected]

LM-064Dr. M R BOOPENDRANATHCENTRE INSTOTUTE OF FISHERIESTECHNOLOGYPO MATSYAPURIKOCHI-682029MOB: 9447665875EMAIL:[email protected]

LM-065Dr. DEBASIS SENGUPTACAOSIISc, BANGLORE-560012PH: 0802 2933066EMAIL: [email protected]


LM-066

Dr. DEBASIS KUMAR MAHAPATRA

CAS, IIT DELHI

HAUZKHAS

NEWDELHI-110016

MOB: 9818306164


LM-067

Dr. G S BHAT

CAOS

IISc, BANGLORE

PH: 0802 2933071


LM-068

Dr. SYED WAJIH AHMAD NAQVI

NIO

DONA PAULA

PH: 0832 2450294


LM-069

Dr. ELGAR DESA

NIO

DONA PAULA

MOB: 9890444851


LM-070

Dr. S. KATHRIROLI

L&T, CHENNAI

MOB: 9444399800

LM-071

Dr. SHAILESH NAYAK

SECRETARY

MINISTRY OF EARTH SCIENCES

GOVT. OF INDIA, NEW DELHI

MOB: 9441013377

LM-072

Dr. S CHIDAMBARAM

DEPT OF EARTH SCIENCES

ANNAMALAI UNIVERSITY

ANNAMALAI NAGAR

MOB: 9842775874


LM-073Dr. RAJAT ROY CHAUDHURYNIOTVELACHERYTAMBARAM ROADPALLIKARANAICHENNAI-600100EMAIL: [email protected]

LM-074Sri. K.M SIVAKHOLUNDUNIOT, PALLIKARANAICHENNAI-601302MOB: 9444399804EMAIL: [email protected]

LM-075Dr. BASANTA KUMAR JENANIOT CAMPUS VELACHERYTAMBARAM ROAD,PALLIKARANAICHENNAI-600100MOB: 9444399850EMAIL: [email protected]

LM-076Dr. RAJKUMAROCEAN SCIENCES DIVISIONMETEOROLOGY & OCEANOGRAPHICGROUPSAC (ISRO), AHMEDABAD-380015MOB: 9898575023EMAIL: [email protected]

LM-077CAPTAIN NVS RAJUINS ZAMORINNAVAL ACADEMYEZHIMALARAMANTHALI POKANNUR-670308MOB: 9496181551EMAIL: [email protected]

LM-078Dr. ARUN CHAKRABORTYCORAL, IIT KHARAGPURKHARAGPUR-721302MOB: 9733539295EMAIL: [email protected]



LM-079Dr. M. RAVICHANDRAN INCOISOCEAN VALLEY PO BOX NO. 21 IDAJEDIMETLAHYDERABAD 55MOB: 94471229296EMAIL: [email protected]

LM-080Dr. K . AJITH JOSEPHGOPAL RESIDENCY II FLOORTHOTTEKAT ROADKOCHI-682011MOB: 09447325564EMAIL: [email protected]

LM-081Dr. V.S.N MURTHY176 LAWSONS BAY COLONYVISHAKAPATNAM-530017MOB: 09951290356EMAIL: [email protected]

LM-082RESHMI SHARMASCIENTISTSPACE APPLICATION CENTREINADIAN SPACE RESEARCHORGANOSATIONAHMADABAD

LM-083DR.SATHEESH CHANDRA SHENOIDIRECTORINCOIS, [email protected]

LM-084Dr. SATHYA NAIDUProf EMERITUSUNIVERSITY OF ALASKAINSTITUTE OF MARINE SCIENCESFAIRBANKS, AK99775, U.S.AMOB: 388-4041EMAIL: [email protected]

LM-085Dr. K GOPALA REDDYDEPT OF METEOROLOGY &OCEANOGRAPHY

ANDHRA UNIVERSITYVISHAKAPATNAM-530003MOB: 9989191239EMAIL: [email protected]

LM-086Dr. PATURY RAJENDRA PRASADDEPT OF GEOPHYSICS

ANDHRA UNIVERSITYVISHAKAPATNAM-530003MOB: 9701155589EMAIL: [email protected]

LM-087Dr. SUJATHA C. HDEPT OF CHEMICAL OCEANOGRAPHY

SCHOOL OF MARINE SCIENCESCUSAT, KOCHI-16MOB: 9995991778EMAIL: [email protected]

LM-088DR.K.S.R.MURTHYC S I R-EMIRITUS SCIENTIST

G3,RAVICHAKRA APARTMENTJ.R NAGAROLD VENKOJIPALEMVISHAKHAPATNAM

LM-089DR.PRASAD KUMAR BHASKARANASST PROFESSOR

IIT KHARAGPURMOB: [email protected]

LM-090Dr. JAYA KUMAR SEELAMNIO, DONA PAULAGOA-403004

PH: 2450316EMAIL: [email protected]

LM-091Dr. N.P. KURIANHEAD MARINE SCIENCE DEVISIONCETRE FOR EARTH SCIENCE STUDIESTRIVANDRUM – 695031

E-MAIL: [email protected]


LM-092Dr. CHANDRAMADHAB PALREADERDEPT. OF PHYSICSRAMAKRISHNA MISSION VIDYAMADIRABELURMATHHOWRAH - 711202E-mail: [email protected]

LM-093DR.G BHARATIPROFESSORDEPARTMENT OF METEROLOGY &OCEANOGRAPHYANDHRA UNIVERSITYVISHAKAPATNAM-530017MOB-08912796080EMAIL.bharathigogineni@yahoo.co.in

LM-094Dr. C. SHAJIASSISTANT PROFESSORCORALIIT KHARAGPURKHARGAPUR -721302EMAIL: [email protected]

LM-095Dr. R. RAGHU PRAKASHSENIOR SCIENTISTCIFT, OCEAN VIEW LAGENTVISHAKHAPATTANAM – 530003EMAIL: [email protected]

LM-096Dr. SSV SIVARAMA KRISHNADEPARTMENT OF METEOROLOGY &OCEANOGRAPHYANDHRA UNIVERSITYVISHAKAPATTANAME-MAIL: [email protected]

LM-097Dr. M.BABABARKATH14, BREEZE ENCLAVEAKKULAM ROAD, ULLOORTRIVANDRUM-695011PH: 0471-2550764MOB. 95677 61403EMAIL: [email protected]

LM-098

Dr. C. ANNAPURANA

PROFESSOR

DEPT. OF ZOOLOGY

ANDHRA UNIVERSITY

VISHAKHAPATANAM- 53003


LM-99

Dr. C. KRISHNAIAH

RESEARCH CO ORDINATOR

OCEAN & ATMOSPHERIC SCIENCE AND

TECHNOLOGY CELL

MANGALORE UNIVERSITY

MANGALA GANGOTRI – 574199


LM-100

Dr. VIBHA SANDIAS SHARMA

SENIOR PROJECT ASSOCIATE

INSTITUTE OF OCEAN MANAGEMENT

ANNA UNIVERSITY

CHENNAI – 600025


LM-101

Dr. USHA NATESAN

PROFESSOR

CENTRE FOR ENVIRONMENTAL STUDIES

ANNA UNIVERSITY

CHENNAI 600025


LM-102

Dr. K. RAVINDRAN

49/ 172 –D

CHITRANJALI

BLOSSOM ROAD

ELAMAKKARA

COCHIN – 682026


LM-103

DR. M.K. MUKUNDAN

PRICIPAL SCIENTIST

CIFT

COCHIN 29




LM-104Dr. MARATHADU SUDHAKARADVISOR / SCI gMINISTRY OF EARTH SCIENCEBLOCK -12CGO COMPLEXLODHI ROADNEW DELHI – 110003E-MAIL: [email protected]

LM-105Dr. K.V. JAYACHANDRANPROFESSORDEPT. OF FISHERY BIOLOGYCOLLEGE OF FISHEIRESKAU, COCHIN- 682506E-MAIL: [email protected]

LM-106Dr. VINU K VALSALAGOSAT, CRER,NATIONAL INSTITUTE FORENVIRONMENTAL STUDIESTSUKUBA, IBARAKIJAPPAN -305-8506E-MAIL: [email protected]

LM-107Sri. DEBADATTA SWAINSCIENTIST, OCEANOGRAPHICDEVISION(AS&OG)NATIONAL REMOTE SENSING CENTREISRO, BALANAGAR, HYDRABAD 500037TEL:- 040 23884576EMAIL: [email protected]

LM-108Dr. P. NAMMALWARFORMER PRICIPAL SCIENTIST (ICAR)121/46, SECOND STREETKAMARAJ AVENUE, JUSTICE RAMASWAMYROAD, ADAYAR -600025EMAIL: [email protected]

LM-109Sr. I. O.R. NANDAGOPANQTR 14, TYPE -5NPOL RESIDENTIAL COMPLEXTHRIKAKKARA, KOCHI – 682021EMAIL: [email protected]

LM-110Dr. K. RAJITHICI- HOLY FAITH RESIDENCYTHRIKAKARAKOCHI- 682021EMAIL: [email protected]

LM-111

Dr. M.A. ATMANANDNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI,CHENNAI – 600100EMAIL : [email protected]

LM-112

Dr. G.A. RAMADASSNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAICHENNAI – 600100EMAIL : [email protected]

LM-113

Shri. VIJAYA RAVICHANDRANCOASTAL AND ENVIRONMENTALENGG. DIV.NIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI

CHENNAI – 600100EMAIL : [email protected]

LM-114Dr. S. MUTHU KRISHNA BABUNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI, CHENNAI – 600100

EMAIL : [email protected]

LM-115Sri. KARUNAKAR KINTADACOASTAL AND ENVIRONMENTALENGG. DIV.NIOT, VALANCHERYTHAMBARAM MAIN ROAD

PALLIKARANAICHENNAI – 600100EMAIL : [email protected]


LM-116Dr. PURNIMA JALIHALGROUP HEAD – EFW / DESALINATIONNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI, CHENNAI – 600100EMAIL : [email protected]

LM-117Dr. S. RAMESHNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI, CHENNAI – 600100EMAIL : [email protected]

LM-118Dr. S. SUNDARARAJANCOASTAL AND ENVIRONMENTAL ENGG.NIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI, CHENNAI – 600100EMAIL : [email protected]

LM-119K. AMUTHADEEP SEA TECHNOLOGIESNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI, CHENNAI – 600100EMAIL : [email protected]

LM-120N. RAVI ALIYAS GURUSWAMYVESSEL MANAGEMENT CELLNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI, CHENNAI – 600100EMAIL : [email protected]

LM-121M.SHANKARVESSEL MANAGEMENT CELLNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAI, CHENNAI – 600100EMAIL : [email protected]

LM-122P. MURUGESHOCEAN OBSERVATION SYSTEM

NIOT, VALANCHERY

THAMBARAM MAIN ROAD

PALLIKARANAI, CHENNAI – 600100


LM-123

A.N. SUBRAMANIAN

SUNMERSIBLES &GAS HYDRATES

NIOT, VALANCHERY

THAMBARAM MAIN ROAD



LM-124

Dr. G. LATHA

OCEAN ACOUSTICS & MODELLING GROUP

NIOT, VALANCHERY

THAMBARAM MAIN ROAD



LM-125

Dr. G.VEMKATESAN

NIOT, VALANCHERY

THAMBARAM MAIN ROAD



LM-126

Dr. M. KALYANI

NIOT, VALANCHERY

THAMBARAM MAIN ROAD



LM- 127

PRANESH. S.B

NIOT, VALANCHERY

THAMBARAM MAIN ROAD



LM- 128

Dr. J. MANECIUS SELVA KUMAR

NIOT, VALANCHERY

THAMBARAM MAIN ROAD





LM-129V. SUSEENTHARANCEE GROUPNIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAICHENNAI – 600100EMAIL : [email protected]

LM-130Dr. PRINCE PRAKASH JEBA KUMAR.JCOASTAL AND ENVIRONMENTALENGG. DIV., NIOT, VALANCHERYTHAMBARAM MAIN ROADPALLIKARANAICHENNAI – 600100EMAIL : [email protected]

LM131Dr. T. SUNILSCIENTIST DNPOLKOCHI 21

LM-132DOMONIC RICKY FERNANDEZSCIENTIST CNPOLKOCHI 21EMAIL: [email protected]

LM-133DR.K.MOHANKUMARPROFESSORDEPARTMENT OF ATMOSPHERIC SCIENCECUSATLAKE SIDE CAMPUS, FINE ARTS AVENUECOCHIN 16EMAIL :- [email protected]

LM-134DR.TATASUDHAKARSCIENTIST ENIOTPALLIKARANAICHENNAI – 600100EMAIL: [email protected]

LM- 135PSV JAGADEESHSCIENTISTNPOL, THRIKKAKARAKOCHI 21EMAIL: [email protected]

LM- 136Dr. ROSAMMA STEPHENSCIENTIST FAJANTHAKALOOR – KADAVANTHRA ROADKOCHI - 682017

LM 137Dr. V.V. GOPALAKRISHNASCIENTISTPHISICAL OCEANOGRAPHIC DEVISIONNIO, DONA PAULAGOA - 403004

LM 138Dr.P.M. MURALEEDHARANSCIENTIST FPHISICAL OCEANOGRAPHIC DEVISIONNIO, DONA PAULAGOA - 403004

LM 139Mr. SURA APPALA NAIDUPROJECT ASSISTANTNIO, REGIONAL CENTRE8-44-1/5,PLOT NO : 94CHINNA WALTAIR,VISHAKAPATNAM- 530003

LM 140Dr. K. SUDARSANGROUP HEAD (ENGG.SCIENTIST FPOL, THRIKKAKARA POSTKOCHI-21

LM 141Mr. PADMANABHAM MADATHALASCIENTISTNPOL, THRIKKAKARA POSTKOCHI-21

“The Wave Glider: a wave powered autonomous surfacevehicle for operational & predictive oceanography”

Neil Trenaman

Vice President of International Business Development, Liquid Robotics, Inc.

The Wave Glider wave-powered unmanned maritime vehicle (UMV), represents a noveland unique approach to persistent ocean presence. Wave Gliders harvest the abundantenergy contained in ocean waves to provide essentially limitless propulsion while twosolar panels continuously replenish batteries that are used to power the vehicle’s controlelectronics, communications systems, and payloads. Wave Glider is a hybrid sea-surfaceand underwater vehicle in that it is comprised of a submerged “glider” attached via atether to a surface float.

The Wave Glider is well suited for air-sea surface investigations. With a continuous viewof the sky the vehicle makes use of GPS for precise navigation and iridium, or other RFcommunications, for command and control. The Wave Glider can operate as a vessel,covering long distances in the ocean, or as a station-keeping platform. Test results, to beincluded in this presentation, will discuss both roles.

In this presentation, we review the design of this platform and present results from theextensive engineering sea trials conducted with prototype and production versions ofthe vehicle. The vehicle’s performance in a variety of ocean conditions — varying seastate, wind speed, and surface currents — is discussed. Differing wind and waveconditions yield varying performance of the Wave Glider. Field experience and analyticalresults will be presented. While each situation is unique experience indicates the WaveGlider can achieve an average speed of 1.5 knots.

In addition to the basic Wave Glider technology we will focus on the role of currents inthe operation of the vehicle and as an application. Liquid Robotics operators have becomefamiliar with a variety of ocean environments including the Pacific Ocean between Hawaiiand California and the Gulf of Mexico. Field experience will be discussed. Recent projectshave explored the Wave Glider’s ability to enter a “drifter” mode by entering a lockedturn. Preliminary assessments of this approach will be presented.

The Wave Glider is also able to carry a water speed sensor for the evaluation of relativevelocity through the water. Combined with GPS measurements of velocity relative to theearth the immediate surface current may be derived. An analysis of this technique willbe presented. Finally this presentation will discuss the integration of an acoustic Dopplercurrent profiler (ADCP) on the Wave Glider. The technical implementation andpreliminary data results will be described.

OCEAN SOCIETY OF INDIA(Regn No: ER 360/06)c/o Regional Centre, National Institute of OceanographyPost Box No: 1913, Dr. Salim Ali Road, Kochi - 682018www.oceansociety.in [email protected]

PLEASE FILL IN BLOCK CAPITALS

I wish to join the Ocean Society of India as

LIFE MEMBER (LM) MEMBER (M) STUDENT MEMBER (SM)

From Calendar Year* 20____.

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E-mail:

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Received by Secy., OSI (Date) Verified by: GC Meeting Date: GC Decision:

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*Membership Dues: (For Calendar Year)Life Member: One Time Payment of 2500 ORThree Instalments of 1000 within the yearMember (Annual) 300Student Member 100

MEMBER SINCE 20_____/_____/_____/_____/ _____/

LM Installments: 2)____________ 3)______________

Completed Forms to reach: Dr. C. Revichandran, Gen. Sec., OSI, c/o Regional Centre, National Institute of

Oceanography, Post Box No: 1913, Dr. Salim Ali Road, Kochi – 682018

Membership fee: Enclosed DD in f/o “OCEAN SOCIETY OF INDIA “payable at (09485) SBI, M.G. Road, Kochi orMoney transfer to- S.B. Acc. No. 30050 210573 State Bank of India, M.G. Road, Kochi.

Technologies for Ocean Exploration · E.Chandrasekar, M. Murugesh, Radhakrishnan and C. Jothi. viii...

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Transcript of Technologies for Ocean Exploration · E.Chandrasekar, M. Murugesh, Radhakrishnan and C. Jothi. viii...