This month’s newsletter is devoted to data assimilation and its application to Ocean Reanalyses.

Brasseur is introducing this newsletter telling us about the history of Ocean Reanalyses, the need for such Reanalyses for MyOcean users in particular, and the perspective of Ocean Reanalyses coupled with biogeochemistry or regional systems for example.

Scientific articles about Ocean Reanalyses activities are then displayed as follows: First, Cabanes et al. are presenting CORA, a new comprehensive and qualified ocean in-situ dataset from 1990 to 2008, developped at the Coriolis Data Centre at IFREMER and used to build Ocean Reanalyses. A more comprehensive article will be devoted to the CORA dataset in our next April 2010 issue. Then, Remy at Mercator in Toulouse considers large scale decadal Ocean Reanalysis to assess the improvement due to the variational method data assimilation and show the sensitivity of the estimate to different parameters. She uses a light configuration system allowing running several long term reanalysis. Third, Ferry et al. present the French Global Ocean Reanalysis (GLORYS) project which aims at producing eddy resolving global Ocean Reanalyses with different streams spanning different time periods and using different technical choices. This is a collaboration between Mercator and French research laboratories, and is a contribution to the European MyOcean project. Then, Masina et al. at CMCC in Italy are presenting the implementation of data assimilation techniques into global ocean circulation model in order to investigate the role of the ocean on climate variability and predictability. Fifth, Smith et al. are presenting the Ocean Reanalyses studies at ESSC in the U.K. which aim at reconstructing water masses variability and ocean transports. Finally, Langlais et al. are giving an example of the various uses of ocean reanalyses: they are using the Australian BlueLink Reanalysis in order to look into details at the various Southern Ocean fronts.

• Ocean reanalyses: prospects for multi-scale ocean variability studies By Pierre Brasseur
• CORA -Coriolis Ocean database for Re-Analyses-, a new comprehensive and qualified ocean in-situ dataset from 1990 to 2008. By Cécile Cabanes, Clément de Boyer Montégut, Karina Von Schuckmann, Christine Coatanoan, Cécile Pertuisot, Loic Petit de la Villeon, Thierry Carval, Sylvie Pouliquen and Pierre-Yves Le Traon
• Large scale ocean variability estimated from a 3D-Var Reanalysis: sensitivity experiments  By Elisabeth Remy
• Mercator Global Eddy Permitting Ocean Reanalysis GLORYS1V1: Description and Results  By Nicolas Ferry, Laurent Parent, Gilles Garric, Bernard Barnier, Nicolas C. Jourdain and the Mercator Ocean team
• Re-analyses in the Global Ocean at CMCC-INGV: Examples and Applications By Simona Masina, Pierluigi Di Pietro, Andrea Storto, Srdjan Dobricic, Andrea Alessandri, Annalisa Cherchi
• Ocean Reanalysis Studies in Reading: Reconstructing Water Mass Variability and Transports By Gregory C. Smith, Dan Bretherton, Alastair Gemmell, Keith Haines, Ruth Mugford, Vladimir Stepanov , Maria Valdivieso and Hao Zuo
• Southern Ocean Fronts in the Bluelink Reanalysis By Clothilde Langlais, Andreas Schiller and Peter R. Oke