Satellite Detection of Summer Chlorophyll-a Bloom in the Gulf of Tomini

Seasonal variation of chlorophyll-a (Chl-a) concentration in the Gulf of Tomini (GT) is investigated using SeaWiFS-derived sea surface Chl-a, QuikSCAT-derived ocean surface wind vector and Pathfinder sea surface temperature (SST) measurements. Results show that Chl-a concentration in the GT attained maximum in August (0.59 mg/m3) and is primarily controlled by monsoon winds. During summer, strong winds pass through the Maluku archipelago and blast out toward the Maluku Sea, and impinge the coastal mountain on the southeastern GT (GT tip). As a result, a strong wind jet observed at the open-ocean of GT and is suspected to be the main driving force for the Chl-a bloom in the region. The center of the bloom is located consistently with the wind stress maximum (0.28 Nm-2) and low SST (27.3°C ). The present study describes the seasonal and spatial distributions of the Chl-a bloom in GT and its associated oceanographic features.