Circulation in the Timor Sea


  • George Cresswell,

  • Andrea Frische,

  • Jan Peterson,

  • Detlef Quadfasel


In October 1987 and March 1988, measurements were taken across the Sahul shelf and the southwestern end of the Timor Strait to the edge of Indonesian waters. The shipboard instrumentation comprised a conductivity-temperature-depth (CTD) rosette, an acoustic Doppler current profiler (ADCP) and a Pegasus dropsonde. Complementary data came from satellite-tracked drifters, continental shelf moorings, and a Nansen bottle survey in 1976. Pegasus and ADCP measurements in the strait suggested a total transport of about 7 Sv toward the Indian Ocean, with about half of this in the upper 350 m. However, transports may at times be higher, because a drifter in July 1983 revealed speeds of l m s−1 in the strait, twice those measured on the surveys. Data from moored current meters implied a transport on the shelf of roughly 1 Sv, except in the autumn transition of the monsoon in 1985 when it exceeded 3 Sv. Water properties measured on the 1987 and 1988 surveys suggested components from the Flores and Banda seas, Indian Ocean Central Water and a high-salinity subsurface plume from evaporation on the inner Sahul shelf.