Summertime phytoplankton blooms and surface cooling in the western south equatorial Indian Ocean

摘要: Chlorophyll-a (Chla) concentration derived from the Sea viewing Wide field of View sensor (SeaWiFS) data (January 1998 to December 2010) shows phytoplankton blooms in western south equatorial Indian Ocean (WSEIO) during summer monsoon. The mechanism that sustains is investigated with high-resolution General Circulation Model for Earth Simulator (OFES) products. WSEIO are separated coast; they occur June, reach their maximum August, and decay October. With monsoon onset, cross-equatorial wind induces open-ocean upwelling WSEIO, uplifting nutricline. mixed layer heat budget analysis reveals both thermal forcing ocean processes important seasonal variations SST, especially wind-driven entrainment plays a significant role cooling WSEIO. These cause nutrient enrichment surface trigger blooms. As develops, strong deepens layer; thus increases supply enhances bloom. Horizontal advection associated Southern Gyre might also be an process This large clockwise gyre could advect nutrient-rich water along its route, allowing Chla bloom larger area.