Page 1 Hal Ritchie and many collaborators Recherche en Prévision Numérique (RPN) Meteorological...

Hal Ritchie and many collaborators

Recherche en Prévision Numérique (RPN)Meteorological Research Division, Science and Technology Branch

Expert Meeting on Upper Ocean-Atmosphere Interactions, Exeter, December 2009

Sea Ice and Air-Sea Surface Exchange: Impacts in the Canadian

Coupled Atmosphere-Ice Ocean Forecast System

2

Collaborators• Research Division (RPN)

– Pierre Pellerin, Michel Valin, Djamel Bouhemhem, Greg Smith

• National Lab for Marine & Coastal Meteorology

– Hal Ritchie, Serge Desjardins

• CMC– Manon Faucher, Francois Roy, Bertrand

Denis (CMDN)– Lewis Poulin, Dominic Racette, Doug

Bender, Yves Pelletier, Mark McCrady (CMOI)

– Richard Moffet (A&P)

• Regional weather offices– Atlantic & Quebec Storm Prediction

Centres

– Newfoundland & Labrador Office

• Canadian Ice Service (CIS)– Tom Carrières, Paul Pestiau

• Fisheries and Oceans Canada (DFO)

– Maurice-Lamontagne Institute (IML)

• Denis Lefaivre

1) Impacts in the Gulf of St-Lawrence fully coupled Atmosphere-Ocean- Ice forecast system

2) R&D Strategy to Expand and Globalize the coupled system.

Outline:

Development of the Gulf St-Lawrence forecast system A first operational fully coupled Atmosphere-Ocean-Ice

Gulf of St. Lawrence

N. Atlantic

The Gulf of St. Lawrence (GSL) forecast system: • Initiated 13 years ago by the Maurice Lamontagne Institute (DFO)

and Recherche en Prévision Numérique (EC) • Between January and March the GSL is nearly entirely ice covered • Ice conditions can change very rapidly• Coastal weather is strongly affected by the ocean conditions. • During the ice period, both systems are particularly interdependent.• To improve atmospheric forecasts (icing, clouds, fog,…)• To improve ocean-ice forecasts (ice, currents, temperature, waves…)• To improve services: GSL is a major seaway• Users: EC, coast-guard, DFO, maritime transportation, DND• Very interesting laboratory: Semi-enclosed sea

Circulation is controlled : • by tides, • exchanges with atmosphere, • runoff from land,• the seasonal ice cover, • and the inflow through the bounding

straits

Models & Coupling strategy

• Atmosphere: Global Environmental Multi-scale (GEM):– Regional configuration LAM @ 15km - 2.5 km and 58 levels;

• Ocean: Gulf of St. Lawrence Model (ROM, Saucier et al. 2003):– 3D Ocean @ 5km and 73 levels; version 4.9.5 (5.2.2);– Sea-ice (dynamic - thermodynamic);

• Elastic-viscous-plastic (EVP) model (Hunke & Dukowicz, Los Alamos CICE model, 1997);

• Thermodynamics: Semtner, 1976;• Coupler OASISv3-Gossip (Valcke 2004)

Methodology

AtmosphereOcean-Ice

Each: 600 seconds

IR and Vis flux, Humidity, Pressure, Winds, Precipitation, Temperature.

Heat and Vapour Flux IR flux .

15 kmtimestep=600s

5 kmtimestep=300s

Coupler

CouplerCoupling description

Ice fraction48h forecast2 way coupled

Atmosphere-Ocean-IceAn interesting Case

Case: Particularly interesting given that the intense atmosphericcirculation that dramatically changed the Ice conditionsin only 48 hours was preceded by a cold and relatively quiet period.

C

d)

A

C

0

20

40

60

80

%

Anticosti

Clouds

Clouds

Ice

Water

Ice Observation Forecast (coupled) Ice

Valid: 14/03/97 20 Z after 44 hours

Atmosphere-Ocean-IceAn interesting Case Ice Forecast


Difference Air temp.Coupled - Uncoupled

Impact on surface air temperature

Impacts on low level clouds (air-ocean exchanges)

Uncoupled Fully coupleda) b)

c)

WaterIce

Clouds

AVHRR

Nov

a-S

coti

a

New-Brunswick

P-E. I.

Cape-Breton

M. I.

CloudsoverIce

Ice

WaterIce

Ice


Data:

• Hourly air & dew point temperature, surface pressure, cloud cover

• 6-hourly precipitation accumulation

Objective Evaluation (Surface observations)

44 stations

Operational implementation

04/11/23 Page 12

Mont-Joli, 06 Feb. 2008

GEM Coupled Observations


Fully Coupled system VS Operational GEM (48 hours forecast)

GEM Operational(Uncoupled)

~ 24 hours

Impact on atmospheric variables

Winter 2008

Forecast hour

% Coupled System better (> 50%)


TemperatureHumidityCloudsPrecipitationSurface pressure

Surface temperature (TT)

Forecast hour

Dew point temperature (TD)

Forecast hour

Statistics for February 2008

UncoupledFully coupled


Summary: • EC and DFO have successfully developed a fully-interactive coupled

atmosphere-ice-ocean forecasting system for the Gulf of St. Lawrence • This system will become fully operational at the Canadian

Meteorological Centre (CMC) this winter• Results during the past year have demonstrated that the coupled

system produces improved weather forecasts in and around the GSL during all seasons

– Shows that atmosphere-ice-ocean interactions are indeed important even for short-term Canadian weather forecasts

• Used by Canadian Ice Service, Coast-Guard, Department National Defence

Operational Coupled Atmosphere-Ocean-Ice system Gulf of St. Lawrence

1) Impacts in the Gulf of St. Lawrence fully coupled Atmosphere-Ocean-Ice forecast system

2) R&D Strategy to Expand and Globalize the coupled system.

Outline:

17

Canada requires ocean forecasts and information services for:

– Weather prediction– Sea ice prediction (e.g. CCG: seal hunt,

navigation)– Fisheries and aquaculture management– Increased understanding of biological field

observations– Attribution and mitigation of regional climate

change impacts– Risk assessment for extreme events (sea

level, waves, currents)– Search and Rescue, dispersion of pollutants

Global Coupled System

Mercator-Canada Partnership

Summary: • In 2005 Environment Canada, Department of Fisheries and Oceans and

Department of National Defense recognized a common need for products and modeling capabilities that can be provided by an operational global coupled atmosphere-ocean-ice data assimilation and prediction system

• MERCATOR was recommended by an inter-departmental advisory panel to become a partner in the development of an operational Canadian coupled atmosphere-ocean-ice data assimilation and modelling capability


4 years later: • A MOU among the three departments is now in place: Research,

Development and Implementation of Operational Coupled Atmosphere-Ocean-Ice Assimilation and Prediction Systems for Canada

• A letter of intent between Canada and Mercator put in place– Collaborations and Exchanges underway– The current operational ocean model of the Mercator-Ocean group

has been installed in Canada and is now used as common research system between DFO-EC

• An International Memorandum of Understanding (MOU) between Canada and the Mercator Océan is being drafted and is under review

– Main objective: Build a medium-long term perspective of collaboration between the two groups

http://www.mercator-ocean.fr/en/

Core Projects

Atmosphere

Ice-Ocean

Data Assimilation

Observations

Models

Atmospheric Forecasts

Products

Data Assimilation

Observations

Models

Project 1:Project 1: Atm-Ice-Ocean Coupling (models and data

assimilaton)

Project 2:Project 2: Ice-Model

Project 4:Project 4: Ice Data Assimilation

Ice-ocean Forecasts

Products

Project 3:Project 3: Ocean Data Assimilation and Ice-Ocean Forecasting


Project 1: Gulf St-Lawrence

Atm.-Ocean-IceShort termHigh-Resolution

Project 3: Great-Lakes

Atm.-Lakes-IceShort termHigh-Resolution

Project 2: ArcticAtm. – IceShort term forecastsHigh-Resolution

ORCA025

Project 4: Global

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