Presentation on theme: "Mercator Ocean activity"— Presentation transcript:
1Mercator Ocean activity Yann Drillet and Mercator Ocean team
2Outline Operational production and services R&D activities Conclusions ModelAssimilationOSE/OSSEIntercomparisonConclusions
3Mercator Ocean operational production and services Monitoring of the quality:Monitoring of the production : Production is delivery in time in more than 98%Monitoring the of users
4Carateristitics of the systems GlobalIBIRTRANPhysical modelNEMO ¼° and 1/12° 50LNEMO ¼° 75LNEMO 1/36° 50L tide and pressureNEMO 1/12° 75L Tide and pressureBiogeochemistrymodelPISCES ¼° forced by RT ¼°PISCES ¼° forced by free simulation ¼°N/APISCES 1/12° onlineAssimilationSEEK and 3Dvar bias correction (SLA, SST, T/S)SEEK and 3Dvar bias correction (SLA, SST, T/S, ICE)N/A weekly initialised with 1/12° solution. In developmentAtmospshericForcingECMWFERA interimPeriod2007 (2013)-RT2010-presentProducts available on MyOcean (http://www.myocean.eu/) and MercatorPart are distributed on ftp server GOV multi model approachLellouche et al., 2013, Ocean Science.
5Useful tool for mapping errors velocities for drift applications Quality of the analyses and forecast, Lagrangian drift- Drifters give observed velocities and positions.- Model velocities give virtual positions.Distance between observed and virtual positions after 1 dayAnd after a 3-day Lagrangian driftUseful tool for mapping errors velocities for drift applicationsScott et al., 2012; Drévillon et al., 2013, Ocean Dynamics + QuO Va Dis?
7Ocean Model NEMO consortium at european level. Partnership between Global and regional ocean physic and biogeochemistry configurationsReference simulation : global 1/12°Sensitivity experiments:Numerical scheme in NEMO model, advection, diffusion, mixingSurface forcingCoupling physical ocean with atmosphere, Sea Ice and biogeochemistry
8Impact on advection and diffusion schemes on global 1/12° configuration UBSEEN 1EEN 2EEN 3.
9AssimilationBias correctionObservation errorEnsemble approachAssimilation of new observations (sea ice, surface velocity)
10Adaptive tuning of observations errors The prescription of observation errors in the assimilation systems is often too approximate...Ideally, ratio=1ratio < 1 => obs. error overestimatedratio > 1 => obs. error underestimated[ residual (innovation)T ]RERatio Desroziers =aJason1EnvisatSSTThe objective of this diagnostic is to improve the error specification by tuning an adaptive weight coefficient a acting on the error of each assimilated observation.
11Adaptive tuning of observations errors The prescription of observation errors in the assimilation systems is often too approximate...Ideally, ratio=1ratio < 1 => obs. error overestimatedratio > 1 => obs. error underestimated[ residual (innovation)T ]RERatio Desroziers =Jason1EnvisatSST
12Adaptive tuning of observations errors - SLA - cmEnvisat error on without tuningcmEnvisat error on with tuningFit Slope= 0.78Fit Slope= 0.71
13OSEs and OSSEs experiments Sensitivity of the forecasting system to current observations networkNumber of altimeter satelliteArgo vs other in situ observationsNew satellites in the system (Saral, HY2)Design/impact of new observation networkDeep argoSWOT
14(5day-Assimilation window) SWOT OSSESimulated Observations from IBI36 (Free Model, 1/36°~3km, 2009) :SSH : (25 hours mean ; Inverse Barometer and tide removed)Altimeters : J2, J1n, EnSwot ( 7Km)Insitu : Temperature and salinity profiles (CORA Data positions)SST : Daily Mean with 25 Km for horizontal resolutionSSH From NR(IBI36) : 09-14/03/2009(5day-Assimilation window)J2; J1n; En SwotSSH IBI36 : 12/03/2009
15Ssh Correlation (2009) : NR(Data) vs FreeSim vs OSSE1 vs OSSE2 NR/FreeSimMean : 59%NR/OSSE1Mean : 72%NR/OSSE2Mean : 80%NR (IBI36, ‘True Ocean’)FreeSim; OSSE1; OSSE2
16Model intercomparison Ryan et al, GODAE OceanView Class 4 forecast verication framework: Global ocean inter-comparison
17ConclusionsOperational service with daily forecastUpdate annually ocean reanalysisIn development new version of the global 1/12° analysis and forecasting system.R&D work to improve the system and to improve interaction and coupling with atmosphere, sea ice, biogeochemistry.Development of assimilation scheme (SAM2) and NEMO modelInvolvement in GOV TT