High-level multi-temporal Chlorophyll a concentration products are generated from daily data of the MERIS and MODIS sensor as received by OD Nature from ACRI-ST in the framework of the ENVISAT Cat-1 AO 1521 and the MARCOAST-2 project.
In the case of the MERIS sensor, the algorithm used to derive data corresponds to the MERIS algal2 product in case 2 waters and the MERIS algal1 product in case 1 waters (more detailed information available on request). Quality control has been applied according to the standard MERIS product confidence flags. In case of the MODIS data, a flagging procedure for turbid pixels is used to detect where the MODIS Chl is likely to be contaminated. This is done using a model relationship between normalized water radiance at 667nm (nLw667) and Chl for case 1 waters. Details on this flagging procedure can be found in Park et al. 2009.
A visual check has been made by OD Nature of (not supplied) monthly products checking MERIS geolocation, etc.
The daily chlorophyll concentration maps are supplied at a 2km spatial resolution for the entire region of the European Seas.