A hydrographic and bio-chemical climatology of the Mediterranean and the Black Sea: a technical note on the use of coastal data

The aim of the MEDAR/MEDATLAS II project was to archive and rescue multidisciplinary in-situ hydrographic and bio-chemical data of the Mediterranean and the Black Sea through a wide cooperation of countries and to produce a climatological atlas of 12 core parameters, which include temperature and salinity, dissolved oxygen, hydrogen sulphur, alkalinity, phosphate, ammonium, nitrite, nitrate, silicate, chlorophyll and pH. Gridded fields have been computed using the Variational Inverse Model and calibrated by Generalized Cross Validation, by making usual assumptions on the statistical distribution of data and errors. They have been produced for both the Mediterranean and the Black Sea and several additional sub-basins including the Alboran Sea, the Balearic Sea, the Gulf of Lyons and the Ligurian Sea, the Sicily Strait, the Adriatic Sea, the Aegean Sea, the Marmara Sea and the Danube shelf area at climatic, seasonal and monthly scale when relevant. Inter-annual and decadal variability of T/S for both basins have been computed as well. The resulting atlas is made available, free of charge, at "http://modb.oce.ulg.ac.be/Medar" and on CD-Rom. We discuss here some technical issues relating to the use of coastal data in the objective analysis and provide a few examples of features appearing in the climatology. We finally suggest further possible improvements to the analysis method