Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin Activités de la modélisation de la banquise à Mercator G. Garric (Mercator Océan) et R. Bourdallé-Badie (CERFACS) The Model LIM2 in the Mercator systems. Current status of sea ice in the global ¼°operational system Recent advances The update LIM2_EVP Diurnal cycle (and ERAinterim) Tests of LIM2_EVP in the global eddy-resolving model (1/12°) Conclusions and Plans Objectives: Global 1/12° operationnal in 2012 with assimilation of sea ice Sea Ice reanalysis ( ?) with the global ¼° Modelling group (G. Garric & R. Bourdallé-Badie) : development of a sea ice model suitable (‘Mean Sate’) for assimilation. Assimilation group (C.-E. Testut & E. Greiner) : development of an assimilation scheme for sea ice quantities (concentration and speed).
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Global systems 2° Low resolution (PSY2G2). Last release in June 2008 (ON since September 2003) (target : IC for seasonal prediction, reanalysis). ¼° Eddy permitting (PSY3V2). Last release in February 2008 (ON since October 2005) (target MYOcean, reanalysis, climate monitoring, sea ice, biogeochemistry…) Sea ice forecasts. 1/12° Eddy resolving (PSY4). Demonstration phase in April 2008 for MERSEA. (target : MYOcean, biogeochemistry) Sea ice forecasts. North Atlantic and Mediterranean Sea systems 1/12° Eddy resolving (PSY2V3) Last release in July 2008 (ON since September 2003) (target: mesoscale upper ocean, downscaling to regional and coastal systems) Sea ice forecasts. 1/12° Eddy resolving (PSY2Q1). Operated daily. ON since June 2008 (target : navy) Sea ice forecasts. IBI (Iberian, Biscayan and Irish) system 1/36° Eddy resolving + tides (PSY ??) Still in development R&D part. (target: backup MYOcean, tides) Current status of Mercator systems Several model configurations operated for several uses
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 The Thermodynamic-Dynamic model LIM2 Collaboration with UCL, Louvain-la-Neuve, Belgium 3-layers model (Semtner, 1976) - 1D vertical diffusion of heat - Surface temperature, brine pockets, snow/iceformation … - Leads parameterisation Transport : Advective scheme from Prather (1986) - Viscous-Plastic rheology from Hibler (1979) - Ice/ocean drag damping necessary (1/4° and 1/12°) THERMODYNAMICS DYNAMICS Fichefet and Maqueda, Sensitivity of a global sea ice model to the treatment of ice thermodynamics and dynamics, JGR (1997). Fichefet and Maqueda, Modelling the influence of snow accumulation and snow-ice formation on the seasonal cycle of the Antarctic sea ice cover, Clim. Dyn. (1999). Goosse and Fichefet, Importance of ice-ocean interactions for the global ocean circulation: a model study, JGR (1999). Timmermann et al., On the representation of high latitude processes in the ORCA-LIM global coupled sea ice-ocean model, Ocean Modelling, (2005).
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Current status of sea ice in operationnal systems Global ¼° configuration (no assimilation of sea ice) AGU fall meeting 2008 Global ¼° configuration Operationnal system IFREMER/CERSAT Satellite data Slight overestimation in winters September 2008 March 2007 September 2008
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 AGU fall meeting 2008 September 2008March 2007 Overestimation in summers Current status of sea ice in operationnal systems Global ¼° configuration (no assimilation of sea ice) Global ¼° configuration Operationnal system IFREMER/CERSAT Satellite data September 2008 March 2007
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Current status of sea ice in operational systems Global ¼° configuration (no assimilation of sea ice) Ice Speed IFREMER/CERSAT Global ¼° operational system
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Recent advances - The update LIM2_EVP - Newly sea ice formed in leads set to 0.6m in NH and 0.5m in SH - Less snowfalls during NH summertime. - EVP (Hunke and Dukowicz,1997) (time scale for elastic waves : 3600s and 360 nbr of iterations for subcycling. - Refreshed ice/ocean drag at each oceanic time step THERMODYNAMICS DYNAMICS Bouillon et al., An elastic-viscous-plastic sea ice model formulated on Arakawa B and C grids, Ocean Model., (2009).
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Sea ice thickness (March 2007) Closer agreement in summer Expected thickness distribution Sept 2007 IFREMER/CERSAT Satellite Data Global ¼° configuration Operationnal system Global ¼° configuration LIM2_EVP Recent advances - The update LIM2_EVP
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Arctic ice coverage anomaly wrt mean seasonal cycle km 2 /yr km 2 /yr km 2 /yr Better capture of the recent trend IFREMER/CERSAT Satellite Data Global ¼° configuraition LIM2_EVP Global ¼° configuration Operationnal system Recent advances - The update LIM2_EVP
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Recent advances - The update LIM2_EVP Ice Speed Slight increase of Ice speed with LIM2_EVP. IFREMER/CERSATLIM2 LIM2_EVP February 2002 LIM2_EVP IFREMER/CERSAT LIM2 November 2002
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin Correlation of CERSAT ( ): km/day/year - LIM2_EVP ( ): km/day/year - IABP ( ): km/day/year (Rampal et al., 2009) Recent advances - The update LIM2_EVP Ice Speed. Monthly mean ice speed (CERSAT region) (km/day) CERSAT LIM2_EVP
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Antarctic Arctic Sea ice extent monthly anomalies Pb with Initial Conditions Pb with the seasonal cycle: too much sea ice in summer Correlation: 0.8 GLORYS with LIM2_EVP IFREMER/CERSAT Recent advances - The update LIM2_EVP Mercator reanalysis GLORYS1V1 (no sea ice assimilation) Interannual variability
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin h forcing (ECMWF) Recent advances - Impact of diurnal cycle (3H) RMS of the wind zonal stress over y2003 Daily forcing (ECMWF) Daily 3h 20/09/ /10/2003
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 CERSAT Data Daily Forcing Sea Ice Fraction March H Forcing Ice Thickness Ice Fraction Ice Thickness Recent advances - Impact of diurnal cycle (3H)
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 IFREMER/CERSATLIM2 LIM2_EVP February 2002 LIM2_EVP 3H Forcing Recent advances – Impact of diurnal cycle (3H) Tests with ECMWF ERAinterim Large increase of ice speed. LIM2_EVP IFREMER/CERSAT LIM2 November 2002 LIM2_EVP 3H Forcing
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Monthly mean ice speed (CERSAT region) (km/day) Recent advances – Impact of diurnal cycle (3H) Tests with ECMWF ERAinterim
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Tests with the global eddy-resolving model (1/12°). LIM2_EVP/3H Forcing IFREMER/CERSATOld ORCA12New ORCA12 16 th March 2002 Insufficient sea ice during summer
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Tests with the global eddy-resolving model (1/12°). LIM2_EVP/3H Forcing IFREMER/CERSATOld ORCA12New ORCA12 11 th September 2002 Insufficient sea ice during summer
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin Plans Implementation of LIM2_EVP in the real time operational systems. Work on the impact of the Diurnal Cycle (3H) in ¼° and 1/12° to be continued. Correction of summer bias : use of ERAinterim reanalysis for reanalysis purposes. Use of Thermodynamics of LIM3 in 2011? with melting ponds? Dynamics (rheology + sea ice drag) in ¼ and 1/12°: rheology EVP at 1/12° ? Use of sea ice data delivered by MyOcean for validation. 2012 (target V2 MyOcean): Global 1/12° with LIM2_EVP or LIM3 Seasonal forecasts with atmospheric forcing from Meteo France? Sea ice reanalysis as a reference for recent years? Thank you!!
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Antarctic Arctic Sea ice extent monthly anomalies Pb with Initial Conditions Correlation: 0.8 GLORYS with LIM2_EVP IFREMER/CERSAT Recent advances – Initial conditions (for sea ice mass) Mercator reanalysis GLORYS1V1 (no sea ice assimilation) Interannual variability Pb with the seasonal cycle: too much sea ice in summer
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 Control (model) Reconstruction from concentration Example : Thickness=f(Ice Surf. Temperature) Thickness Reconstruction from temperature Application to observation of temperature and concentration Recent advances - Initial conditions (for sea ice mass) Get an initial sea ice mass already in equilibrium with the model.
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin ArcticAntarctic Sea ice extent monthly anomalies No noticeable spin up IFREMER/CERSAT Global ¼° experiment Recent advances - Initial conditions (for sea ice mass) Get an initial sea ice mass already in equilibrium with the model.
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin Needs of accurate high resolution of sea ice data… Tests with the global eddy-resolving model (1/12°). 1/12° resolution in Antarctica
Nereus Project, réunion Océano, Toulouse, 30/09/2008 Journée de rencontre Météo France/Mecator/Océan 14 Juin 2010 The model configurations ► 1 code : NEMO (LIM) ► 1 grid : all the configurations are on the same ORCA (tripolar) grid ► One single input dataset : initialization and forcing (ECMWF analysis and forecasts) ► Some of these configurations are shared with the scientific and operational community ORCA025: Drakkar and Glorys Project, Barnier et al. UKMO, CMCC, EC, DFO, … ORCA025 ¼° 1 point sur 12 ORCA12 1/12° ATL12 1/12° NEATL36 1/36°