Imagens do AQUA-MODIS aplicadas à estimativa dos valores de clorofila-a e da temperatura da superfície do mar na zona offshore da Bacia Potiguar no Rio Grande do Norte

Abstract

The availability of a nearly-continuous images from AQUA-MODIS sensor allowed the assessment of chlorophyll-a (Chl-a) and Sea Surface Temperature (SST) maps for 2009 and 2010 for Potiguar Basin offshore region. The effect of climatic phenomena La Niña and El Niño in 2009 and 2010, respectively, is proved in rainy season of 2009 when the amount of accumulated rainfall was above the normal regional influencing the increase of chl-a that reach the average values of 3.6 mg/m³, with emphasis on the areas adjacent to the mouths of the rivers Apodi-Mossoró and Piranhas-Açu. However in 2010 there is no significant variation of chl-a concentrations between the rainy and dry seasons. The SST for the continental shelf and shelf break average temperature was 28°C in both years. The AQUA-MODIS time series images indicated relative warming of the waters from 2009 to 2010, with an average difference of about 0.2°C for continental shelf and of 0.3°C for shelf break area. The multitemporal analysis of continental shelf waters also confirms the high chl-a concentrations andSST values in inner shelf through rainy season due to contribution of continental water with nutrients from estuarine areas. The results highlight the importance of environmental monitoring actions in Potiguar Basin, such as those that have been performed by PETROBRAS