Currents in the Celebes and Maluku Seas, February 1999

Upper ocean currents in the Celebes Sea, the northern Maluku Sea, and the a djacent region to the east were measured during February 1999 using a shipb oard acoustic Doppler current profiler (ADCP) on R/V Kaiyo. The new data pr ovide the first quasisynoptic observations of the circulation within the ce ntral Celebes Sea. South of Mindanao, the Mindanao Current split into three branches. Only the westernmost branch entered the Celebes Sea, where part retroflected around a cyclonic eddy in the western Celebes Sea and part too k a shorter route through the eastern basin before the two paths joined and returned to the Pacific. The remainder of the Celebes Sea branch of the Mi ndanao Current continued toward Makassar Strait. In the central and eastern Celebes Sea, the circulation pattern below 150 m differed substantially fr om that at the surface. The strongest feature was a northward flow that exc eeded 60 cm s(-1) near 230 m in the center of the basin, where shallower cu rrents were weak. A northward transport of 6 Sv in the top 300 m was measur ed across 1.75 degreesN in the Maluku Sea, carrying Indonesian Seas waters northeast toward the Pacific. Water properties and other current sections i n the northern Maluku Sea confirm shallow northeastward flow.