IST/MARETEC, 27 April 2005 The MERCATOR project Dominique Obaton

IST/MARETEC, Lisbon. 27 April 2005 MERCATOR OCEAN n Joined effort of 6 major French agencies to develop operational oceanography : n Strong links with GODAE + European level : GMES (MERSEA) n June 1995 : start of MERCATOR project n January 2001 : first bulletin. Ocean circulation forecast in place n April 2002 : GIP MERCATOR OCEAN is created in Toulouse n Since 2003, 35 people working full time for MERCATOR-Ocean R&D, Exploitation, Distribution, Administration to a real-time ocean forecasts n Today more than 150 referenced users n May 2006 : Mercator Ocean will become a European Center for Operational Oceanography

IST/MARETEC, Lisbon. 27 April 2005 MERCATOR objectives: n To run a high resolution operational (forecast mode) global ocean system n To provide initial and boundary conditions to any coastal systems –1st users and institutes to be served : French agencies which compose Mercator Ocean

IST/MARETEC, Lisbon. 27 April 2005 Global operational ocean system n 2008 : to have a global 1/12° demonstration system –ready to be operational MERSEA objective n Step by step : –Global 2° global ocean forecasting system operational -with assimilation of SLA- ¼° global ocean forecasting system operational by summer MERSEA Global Ocean initial component –High resolution North Atlantic + Mediterranean sea 1/12° (5-7 km) operational system –monovariate assimilation of SLA This system used to provide IC & BC to coastal models 1/12° system + multivariate assimilation : SLA & in situ : operational by summer

IST/MARETEC, Lisbon. 27 April 2005 OPA8.2 ocean code (LODYC, Paris) 2 poles in the northern hemisphere Horiz. mesh : 182  149 points, refined at the Equator (2°  0.5°), isotropic at higher latitudes (~2°) Z coordinate, 31 levels, with an embedded mixed layer model (1.5 order closure scheme for TKE) Diagnostic ice model Surface fluxes : ECMWF The global 2° prototype

IST/MARETEC, Lisbon. 27 April 2005 Ocean code: OPA8.2 (LODYC, Paris) Grid: Global ¼° ORCA-type grid 1442x1021 points (6 to 28 km) 46 levels (6 to 250 m) Bathymetry: ETOPO 2 + BedMap Coastline: IDL – 1 km Initialisation: Lévitus 98 1° + MEDatlas + PHC in Arctic Ocean + mean profile in Red Sea Parametrisation: - Free Surface - Diagnostic Sea Ice: “Glace-IF” then LIM model - Isopycnal diffusion, Biharmonic horizontal viscosity, enhancement of the viscosity in tropical band - Buffer zones at Gibraltar and Bab El Mandeb Straits - Monthly Runoffs for 120 river-mouths Assimilation: - univariate : OI SLA The global ¼° model 6 km 28 km

IST/MARETEC, Lisbon. 27 April 2005 The global ¼° prototype Global ¼° Mercator Circulation in ARCTIC Circulation by Grotefendt et al. (1998)

IST/MARETEC, Lisbon. 27 April 2005 « IF » Ice Model Ice cover in Arctic Global ¼° Mercator

IST/MARETEC, Lisbon. 27 April 2005 Equatorial Pacific currents Johnson et al., oct Global ¼° Mercator EUC NECC NEC EC

IST/MARETEC, Lisbon. 27 April 2005 Comparison Mercator global 2° vs ¼° : SST Mercator ¼°– 10/01/ weeks average Mercator 2° – 10/01/96

IST/MARETEC, Lisbon. 27 April 2005 Comparison Mercator global 2° vs ¼° : current at 50 meters Mercator ¼° – 10/01/ weeks average Mercator 2° – 10/01/96

IST/MARETEC, Lisbon. 27 April 2005 Mercator system prototypes : GLOBAL n La simu de Thierry

IST/MARETEC, Lisbon. 27 April 2005 The global ¼° system n Next improvements in global ¼° system –Louvain ice model –Multivariate assimilation SLA + in situ (temperature + salinity) provided by Coriolis database –… and upgrades in OPA

IST/MARETEC, Lisbon. 27 April 2005 North Atlantic + Mediterranean sea 1/3° 1/15° n North & Tropical ATLANTIC 20°S-70°N –Resolution 1/3° ; 43 levels –Hindcast, Nowcast, Forecast, since January 2001 –Jan Avr 2004 : univariate Assimilation SLA (Cooper & Haines method) –Jan 2004 – present : multivariate assimilation SLA, SST, in situ T&S (EOFs) n North ATLANTIC 20°S-70°N & MED sea –Resolution 1/15° (5-7 km) ; 43 levels –Hindcast, Nowcast, Forecast, since JAN 2003 –Jan present : univariate Assimilation SLA (Cooper & Haines method) –summer 2005 : multivariate assimilation SLA, SST, in situ T&S (EOFs) n PLANS for a new configuration for Atlantic front and Mediterranean sea. Open ocean / coastal needs

IST/MARETEC, Lisbon. 27 April 2005 The high resolution (5-7km) MERCATOR model 5 to 7 km rotated grid in the Atlantic, 1/16° in the Med 43 levels in both basins (19 at Gibraltar Straight) Buffer zone Code: OPA Bathymetry: Smith & Sandwell Forcing: ECMWF daily averaged (wind stress, heat, freshwater) Boundaries: buffer zone (Reynaud climatology) for temperature and salinity. Restoring zone under 500m in Cadiz Gulf. Parameterizations: Rigid lid, z-level, TKE mixing scheme, bilaplacian operator, free slip condition.

IST/MARETEC, Lisbon. 27 April 2005 The high resolution (5-7km) MERCATOR model SSH on 24 March 2003 PSY1 (1/3°) PSY2 (5-7 km ; 1/15°) PSY2v1 (1/15°) 24/3/04 PSY1v2 (1/3°) 24/3/04 PSY2v1 31/3/04 (t+7)

IST/MARETEC, Lisbon. 27 April 2005

Upwelling along Moroccan coast Satellite data (AVHRR, mean) Mercator 1/3° Analysis (altimeter assimilation) Mercator 1/15° Analysis (altimeter assimilation : T/P+ERS+GFO) Sea Surface Temperature Western Africa Upwelling 18 April 2001

IST/MARETEC, Lisbon. 27 April 2005 Salinity section:Florida-Portugal (weekly mean) : Climatology 1/3° + SLA ass. 1/15° + SLA ass. 35psu 1/3° + SLA & in situ

IST/MARETEC, Lisbon. 27 April 2005 Regional scale : 1st objective n To provide initial and boundary conditions to coastal models –Extraction on Mercator fields on a smaller area –Interpolation, extrapolation and optimisation of Mercator fields on a coastal grid (using any other model) n Extraction of Mercator fields available via web by end 2005 n 1st version of interpolation /extrapolation /optimisation tool ready by spring 2006 –via web –Will be upgrade for HYCOM model end 2006

IST/MARETEC, Lisbon. 27 April 2005 Regional scale : 2nd objective n To build regional systems –On the Atlantic front –On the Mediterranean sea n Characteristics: –1/36° horizontal resolution –Refinement of surface layers –Upgrades in OPA : free surface, partial step / σ coordinate –tides –Forced at open boundaries by MERSEA –Assimilation (OI, SEEK) n Objective : be correct on shelf/slope interaction –To provide better (good) initial and boundary conditions to coastal systems n Sense only if –coastal systems –and teams- are interested –End users are interested

IST/MARETEC, Lisbon. 27 April 2005 Which means : n Work with regional and coastal teams –In France –In Europe n Reach end users via coastal teams and specific applications

IST/MARETEC, Lisbon. 27 April 2005 Atlantic front regional system n Idea : downscaling strategy + end user applications : HAB, oil spill, storm surge n Regional system : Mercator & ESEOO II nested in MERSEA n Coastal systems nested –Bay of Biscay : Ifremer –Galician coast : IEO; MeteoGalicia –Iberian shelf : IST/MARETEC –Tagus estuary : IST /MARETEC –Irish shelf : Irish Marine Institute –… n Means : –IBIroos : version 0 National founding –ECOOP (Pierre : steering team) Version 1 European founding n Same strategy for Med. Sea and other European seas