Can satellite-derived chlorophyll imagery be used to trace surface dynamics in coastal zone? A case study in the northwestern Mediterranean Sea

Type Article
Date 2007-06
Language English
Author(s) Forget Philippe1, Andre Gael2
Affiliation(s) 1 : Univ Sud Toulon Var, CNRS, UMR 6017, LSEET, F-83957 La Garde, France.
2 : IFREMER, Ctr Brest, DYNECO, F-29280 Plouzane, France.
Source Sensors (1424-8220) (Molecular Diversity Preservation International), 2007-06 , Vol. 7 , N. 6 , P. 884-904
DOI 10.3390/s7060884
WOS© Times Cited 11
Keyword(s) MARS hydrodynamical model, Surface chlorophyll, SeaWiFS, Gulf of Lions
Abstract A comparison of chlorophyll data from SeaWiFS imagery and modeling results from a 3D hydrodynamical model was performed over the northwestern Mediterranean for the entire year of 2001. The study aims at investigating the information content brought by satellite-derived chlorophyll concentration ([Chl]) maps concerning surface dynamics in coastal zone. The study is mainly focused on the Gulf of Lions (GoL) and its outer region, which are mainly influenced by the Rh ne River, local winds and the Northern Current (NC) flowing from the East along the continental slope. The physical hydrodynamical model was continuously run and 40 SeaWiFS images, presenting a significant coverage of the studied area, were selected. The comparison between [ Chl] and sea surface salinity (SSS) fields on a pixel basis showed no definite correlation trends. Three reasons are given in discussion for that result. However, the comparison emphasized areas close to the coasts which were under the influence of different inputs not considered in the model and also of upwellings. A qualitative analysis of the data performed out of these regions exhibited significant similarities between [ Chl] and SSS features. The signature of the Rh ne ROFI ( Region of Fresh Water Influence) and, in some cases, of the NC, was evidenced on [ Chl] maps. We found that the intensity of this signature is seasonally modulated, e. g., it is low in open sea during the summer, oligotrophic, season. In addition, the signature of the Rh ne ROFI in the western part of the GoL can be only partial due to local chlorophyll deficits. We conclude that, for the regional case studied, chlorophyll imagery can be used as a tracer of surface dynamics through surface salinity but with limitations, especially near the coasts.
Full Text
File Pages Size Access
publication-6205.pdf 10 2 MB Open access
Top of the page