Loisel1, Hubert, Jean-Marc Nicolas1, Davy Merien2, Antoine Sciandra2 and Louis Prieur2

1Laboratoire d’Optique Atmosphérique, Université de Lille 1, F-59655 Villeneuve d'Ascq Cedex, France, Tél: 33-3.20.33.61.89, Fax: 33-3.20.43.43.42, E-mail: loisel@loa.univ-lille1.fr and 2Laboratoire d'Océanographie de Villefranche, B.P. 08, 06238 Villefranche-sur-mer France

 

Biogeochemical variability in the northeast Atlantic as seen from ocean color observations, and comparison with other regions of the Northern Atlantic

 

The spatial distribution and seasonal to inter-annual variability of bio-optical parameters as retrieved from satellite-derived ocean color are described over the northeast Atlantic (15-21W, 38-45N). This area was examined in the frame of the POMME (Programme Océan Multidisciplinaire Méso Echelle) project where extensive field measurements were performed between October 2000 and October 2001. The different bio-optical parameters considered are the chlorophyll concentration, Chl, the absorption coefficient, a, at 412, 443, and 490 nm, the backscattering coefficient, bb, at 490 nm, and the spectral dependency of the particulate scattering, γ. Comparison with in situ measurements are provided. The impact of meso-scale on the repartition of each parameter is discussed, and the temporal evolution of these parameters are also compared with the time evolution of the mixed layer. Different spatio-temporal patterns are noticed between a, bb, γ, and Chl. These differences are interpreted in terms of biogeochemical and physical process. The interpretation of these parameters in terms of dissolved and particulate organic carbon is discussed. At last, the seasonal variability observed over the POMME area is compared with the one observed at other latitudes.