The Seasonal Variability of Sea Surface Temperature and Chlorophyll-a Concentration in the South of Makassar Strait☆

Abstract The sea surface temperature (SST) and chlorophyll-a (Chl-a) variabilities in the south of Makassar Strait were mostly affected by monsoonal wind speed/directions and riverine freshwater inflows. The east-southeast (ESE) wind (May-October) played a major role in an upwelling formation in the region starting in the southern tip of the southern Sulawesi Island. Of the 17 years time period, the variability of the SST values ranged from 25.7 °C (August 2004) - 30.89 °C (March 2007). An upwelling initiation typically occurred in early May when ESE wind speed was at > 5 m/s, whereas the largest upwelling event always occurred in August of each year. Upwelling event generally diminished in September and terminated in October. At the time of the maximum upwelling events (August), the formation of upwelling could be observed up to about 330 km toward the southwest of the southern tip of the Sulawesi island. Interannually, El Nino Southern Oscillation (ENSO) intensified the upwelling event during the east season through an intensification of the ESE wind speed.