SEASONAL AND INTERANNUAL VARIABILITY OF SEA SURFACE CHLOROPHYLL CONCENTRATION IN THE COAST OF SRI LANKA

摘要

Many Indian Ocean fisheries are closely tied to eddy and upwelling variability. During the Southwest Monsoon, increased chlorophyll concentrations were observed from Moderate Resolution Imaging Spectrometer (MODIS) imagery along the southern coast of Sri Lanka. These phytoplankton bloom are associated with high primary productivity and have been attributed to coastal upwelling. Chlorophyll concentrations appeared low during the Northeast monsoon, but feeding aggregations of blue whales (Balaenoptera musculus) along the southern coast indicated evidence of high productivity. This meant that upwelling along the southern coast was prevalent throughout the year, instead of being limited to the Southwest Monsoon as previously thought. This study explored elements of the dynamics of the surface circulation and coastal upwelling in the waters around Sri Lanka using satellite imagery and in-situ observations. Quantifying these processes will be informative in predicting how these wake eddies and the upwelling associated with them might change in the future and, in particular, how they will respond to climate change and global warming.