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.