Role of physical processes in chlorophyll distribution in the western tropical Indian Ocean

摘要: Abstract Physical control of the chlorophyll a (chl a) distribution in western tropical Indian Ocean (WTIO, 8°N to 18°S along 65°E) was studied during 2008 winter monsoon (WM) and 2009 summer (SM). During both seasons, prominent deep maximum (DCM, 0.3–0.5 mg m− 3) observed at all stations between 10°S depth range 50–75 m, but south 10°S, this phenomenon as deeper (~ 120 m) relatively weak (0.15–0.3 mg m− 3). SM, addition seasonal forcing, eddies freshened surface layer also played major roles controlling DCM chl concentrations southern Arabian Sea equatorial Ocean. WM, freshening controlled Seychelles Chagos Thermocline Ridge (SCTR, 5°S–10°S) region by modulating static stability mixed depth. It appears that is associated with core South Equatorial Current. SCTR, predominantly determined anti-cyclonic seasons. The spatial patterns Level Anomaly (SLA) followed most thermocline features study period.