PHYTOPLANKTON BIOMASS ESTIMATE USING REMOTE SENSING OF OCEAN COLOR AND IN SITU DATA IN THE PATAGONIAN CONTINENTAL SHELF

DOGLIOTTI, A.I.

Ciudad de Córdoba

Congreso; Congreso Argentino de Teledeteccion 2012: El medio ambiente y sus cambios: un desafío para la información espacial (CAT-2012); 2012

IAFE

 Ocean color images were used to estimate chlorophyll-a concentration (Chl-a), as a proxy to phytoplankton biomass, to characterize ecological regions within the Patagonian Continental Shelf (PCS). A comprehensive analysis of the main steps required to process ocean color images was performed, i.e. the atmospheric correction scheme, the evaluation of the satellite-derived Chl-a, and a temporal series analysis of Chl-a maps. An algorithm was developed to correct ocean color images from the MMRS (Multi-spectral Medium Resolution Scanner) sensor, onboard the argentine satellite SAC-C. The theoretical performance was good, but the marine reflectance values obtained after correcting MMRS data were low compared to the corresponding SeaWiFS (Sea Viewing Wide Field-of-view Sensor) reflectance. Two global and two regional ocean color products, applied to SeaWiFS and MODIS (MODerate resolution Imaging spectroradiometer) imagery, have been compared to in situ Chl-a measurements collected during five summer and autumn cruises between 2001 and 2004. The OC4v4 standard global algorithm performed better than the other algorithms analyzed; a systematic error was found in the satellite-derived Chl-a showing a general overestimation at low Chl-a and an underestimation at high Chl-a. The analysis of a time series of 6-years of SeaWiFS Chl-a images permitted to identify a differential distribution pattern of pigment concentrations in four regions in the PCS.