Characteristics of Halmahera Eddy and its relation to sea surface temperature, chlorophyll-a, and thermocline layer

Western equatorial Pacific is a confluence region of the water mass from the northern hemisphere and the southern hemisphere. One of the interesting phenomena in this region is Halmahera Eddy. The purpose of this research is to investigate the seasonal variability of the Halmahera Eddy on several depths and its relation to the primary productivity using sea surface temperature and chlorophyll-a parameters. In addition, this research also investigates the influence of the surface currents of the Halmahera Eddy to the thermocline layer. The results show that the Halmahera Eddy on the surface is affected by several currents in the waters of the Western Pacific Ocean and the monsoon system that is strengthened in the East Monsoon-Transition II (June-October), while weakened by the end of Transition II-West monsoon (November-February), Current Depth of Halmahera Eddy pattern strengthening, weakening, shifting every seasons and the currents weaker along with increasing depth. The primary productivity is identified by chlorophyll-a (0.1-0.15 mg/m³) and warm pool (28-31ºC) in Halmahera sea. Halmahera Eddy also can suppress the thermocline layer.