CoAuthors

Jean-Michel Lellouche (Mercator Océan, France); Romain Bourdallé-Badie (Mercator Océan, France); Olivier Le Galloudec (Mercator Océan, France); Eric Greiner (CLS, France); Gilles Garric (Mercator Océan, France); Charly Regnier (Mercator Océan, France); Marie Drevillon (Mercator Océan, France); Clement Bricaud (Mercator Océan, France)

Over the past years, Mercator Ocean has been regularly upgrading its global ocean physical reanalysis through improvements in the ocean model, assimilation scheme and assimilated data sets. Current global systems are based on the NEMO ocean model at 1/12° and the SAM2 data assimilation scheme developed at Mercator Ocean and based on a reduced-order Kalman filter. Along track altimeter data (Sea Level Anomaly – SLA), satellite Sea Surface Temperature (SST), Sea Ice Concentration and in situ temperature and salinity (T/S) vertical profiles are jointly assimilated. Moreover, a 3D-VAR scheme provides a correction for the slowly-evolving large-scale biases in temperature and salinity. This system has been used to produced real time analysis and forecast but also a global reanalysis which cover the full altimetry period from 1993 until real time.
This presentation will provide an overview of the available global products which are disseminated through CMEMS platform and an overall assessment of these global 1/12° ocean forecast and reanalysis highlighting the level of performance and the reliability of these eddy-resolving simulations. Specific focus will be on the representation of meso scale features at global scale and associated eddy kinetic energy at the surface but also at depth. Impact of the model resolution and of the data assimilation of altimetric observations will be detailed based on diagnostics as comparison with observations and eddy characteristics in the reanalysis and Ocean Monitoring Indicators deduced from the available global reanalysis.