1 SWARP: WP2, wave modelling Fabrice Ardhuin, Mickael Accensi, Pierre Queffeulou, Fanny Ardhuin...

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SWARP: WP2, wave modelling

Fabrice Ardhuin, Mickael Accensi,

Pierre Queffeulou, Fanny Ardhuin (Ifremer)

Fabrice Collard (Oceandatalab)

Aron Roland (TU Darmstadt)

http://www.previmer.org/previsions/vagueshttp://wwz.ifremer.fr/iowaga

2wwz.ifremer.fr/iowaga

Outline

1. Building on other projects and developments : IOWAGA (ERC), Waves-NOPP (U.S. ONR) ...

2. Specific developments for SWARP:• Numerics (implementation of new model version) • Development of parameterizations:

- friction below the ice- shorelines & ice-edge reflections- scattering

Estimation of energy & momentum fluxes

3. Hindcasts & forecasts


Building on other projectsand developments

1

wwz.ifremer.fr/iowaga

SWARP Kick-off, February 3, 2014


1. a multi-parameter global wave hindcast

The ERC-funded IOWAGA project integrates - Coastal hydrodynamics

- Air-sea fluxes - Remote sensing

- Microseisms

into a single consistent wave modelling system.→ new version 4.18 of WAVEWATCH III (distributed by NOAA/NCEP) → hindcast database, >40 different parameters (http://tinyurl.com/iowagaftp)

- Results from global multigrid (1993-2013) : GLOBAL : (30' resolution)... up to 80°N only PACE (10'): East Pacific (Alaska to Peru), with Hawaii & ...

ATNW (10'): U.S. East coast + Gulf of Mexico ATNE (10'): Iceland to Morocco (6'). NC (3'): New Caledonia & Vanuatu (3') CRB (3'): Lesser Antilles (Puerto Rico to Venezuela, 3')

1 or 2 runs (with CFSR and / or ECMWF op. Winds)Recent runs : > 9000 full spectra output (along all shorelines + others)

+ finite element zooms in coastal areas


IOWAGA hindcast particularly focused on - better swells (swell dissipation based on Ardhuin et al. GRL 2009) - better high frequency energy ( → Stokes drift, mss, see JPO 2009, 2010) - better directional parameters (Ardhuin & Roland JGR 2012, Ardhuin et al. JASA 2013)

important for acoustic and seismic noise General validation : Rascle & Ardhuin (Ocean Modelling 2013)

– Here are a few plots with data from http://tinyurl.com/iowagaftp


… but GLOBAL : (30' resolution)... up to 80°N only


Specific developments for SWARP

2




Extension to Arctic : just one more grid ? - 12 km polar grid, same as NSIDC or Ifremer-CERSAT sea ice products (concentration and drift from SSM/I + ERS / QuikSCAT / ASCAT)

-first tests : forced by global grid

- next steps : – Two-way nested in multigrid

2. developments for SWARP

Bathymetry for new grid (IBCAO)

Possible higher resolution if needed (12 km Arctic is less expensive that global hindcast)


Parameterizations: Implementation of shoreline reflection on curvilinear grid - could be added for ice edge …

Implementation of viscous & turbulent friction under the ice : Generalization of Liu & al. (JGR 1991) following work on swell dissipation

(Ardhuin & al. 2009, Rascle & Ardhuin 2013, Perignon et al., submitted)- non linear dissipation rate for turbulent cases, no “eddy viscosity”- transition threshold (laminar to turbulent), random waves → smoothing

Scattering term: to be defined Solution method taken from bottom topography scattering (Ardhuin & Magne 2007)



It runs! …

Example of wave data retrieval from SAR imagery (2011/03/04 9h14, Envisat)

WW3 results :

Wave heights from SAR

(not adapted yet to sea ice)

sea ice water



Hindcasts and forecasts

3




2. Tests with different forcing products

Sept 16th :

Yearly sea ice extent minimum

Sept 17th :

Freeze observed by scatt., not by radiometer

Sept 18th :

Freeze observed by both sensors

Interest of the use of both scatterometer and radiometer data for MIZ monitoring

Concentration from

radiometer

Concentration from

radiometer

Concentration from

radiometer

Standard deviation of backscatter data

Scatterometer sensor can detect the very first stage of sea ice


3. Hindcasts & forecasts 2008-2015: Arctic hindcasts

- multi-grid system including 12 km grid- ECMWF winds + ?? ice - higher resolution mesh focusing on ice edge ?

2016: forecasts

Deliverables: Jan 2015 : First version of wave and sea ice models. Data exchanged between the partners, deliverable 2.1 “First wave model results covering the MIZ”

Jan 2016 : Validation completed. Data flows integrated to NavPlanner, deliverable 2.2 “Upgraded wave model”

July 2016 : deliverable 2.3 “Forecast and hindcast simulations for demonstration”


Generic validation: • Altimeters (Hs & mss ): in ice-free water• Permanent buoys: general context (Iceland + Barents Sea )

WIFAR 2012 + other field data validation: • Detailed estimation of spectra, specific validation of wave attenuation

rates

SAR-derived attenuation rates

3. Validation of the wave model

a) wave parameters

Ardhuin et al. 2010

Ardhuin et al. 2010 (Prévimer)

rms erro

r for H

s (%)



The ERC-funded IOWAGA project integrates - Coastal hydrodynamics

- Air-sea fluxes - Remote sensing

- Microseisms

into a single consistent wave modelling system.→ new version 4.18 of WAVEWATCH III (distributed by NOAA/NCEP) → hindcast database, >40 different parameters (http://tinyurl.com/iowagaftp)

- Results from global multigrid (1993-2013) : GLOBAL : (30' resolution)... up to 80°N only PACE (10'): East Pacific (Alaska to Peru), with Hawaii & ...

ATNW (10'): U.S. East coast + Gulf of Mexico ATNE (10'): Iceland to Morocco (6'). NC (3'): New Caledonia & Vanuatu (3') CRB (3'): Lesser Antilles (Puerto Rico to Venezuela, 3')

1 or 2 runs (with CFSR and / or ECMWF op. Winds)Recent runs : > 9000 full spectra output (along all shorelines + others)

+ finite element zooms in coastal areas


Scattering in the MIZ inferred from seismic/acoustic noise ?

3


AGU meeting, San Francisco, December 2013


Hasselmann (1963) : nearly opposing waves generate seismic noise

3. Scattering and noise : theory

k1

k2

KThe interaction of k

1 and k

2 gives

noise at K = k1 + k

2 and f = f

1 + f

2

Resonant interaction if 2 pi f / K = Cs ,

the phase speed of one seismic mode.

For any f, this selects K.

Movie of sea surface elevation

Z = Z1 + Z

2

Any 2nd order quantity like Z2 will

thus contain

K = k1 ± k

2 and f = f

1 ± f

2

Higher order interactions : K = k1 ± k

2 ± k

3

and f = f1 ± f

2 ± f

3 … and so on …


Generic validation: • Altimeters (Hs & mss ): in ice-free water• Permanent buoys: general context (Iceland + Barents Sea )

WIFAR 2012 + other field data validation: • Detailed estimation of spectra, specific validation of wave attenuation

rates

SAR-derived attenuation rates

5.1 Validation of the wave model

a) wave parameters

Ardhuin et al. 2010

Ardhuin et al. 2010 (Prévimer)

rms erro

r for H

s (%)


From wave spectrum to acoustic or seismic noise :

deep water waves : noise source proportional to

Noise is linked to waves in opposite directions. Loud sources in MIZ ??

3. Scattering and noise :

When do we get noise ?

Obrebski et al. (GRL 2012)

FF

Example of seismic records around the Pacific due to « swell collision » :



Different modes

Different modes :

- seismic waves (Rayleigh or body waves) → can be recorded on land !

- acoustic gravity waves (evanescent : local sea state)

100 to 500 mdepthEvanescent modes dominate

(see Cox & Jacobs GRL 1989)



Example of a noise event ...

KBS

DBG

SCO

Green

land

Iceland



Example of a noise event ...

Seismic spectra at SCO

Modeled seismic sources

Hs


1. Bottom friction

Cliffs north of Jan Mayen : strong wave reflection (another day)...


Perspectives

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AGU meeting, San Francisco, December 2013


Les MNT dans la modélisation côtière - Journée Valor'IG09

- Introducing wave dissipation and scattering in the MIZ : – Verification of dissipation with SAR-derived Hs and Tm02 – Scenarii for scattering : how large can it be given seismic records ?

- Deploying pressure sensors 100 to 500 m from the surface?– Direct measurements of evanescent modes → measurement of I(f) integral, a

very strong constraint on scattering strength.

Anybody has a mooring out there?

It works ! Data from SBE26 in 100 m depth (Ardhuin & al. JASA 2013)

1 SWARP: WP2, wave modelling Fabrice Ardhuin, Mickael Accensi, Pierre Queffeulou, Fanny Ardhuin...

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