Since December 1995, the Indonesian throughflow has been monitored in five
major passages as it flows from the Indonesian interior seas to the Indian
Ocean. Pressure differences across the straits enable us to infer the geost
rophic surface flow, : and so provide the first simultaneous time-series me
asurements of surface geostrophic flow through these passages. Intraseasona
l signals (30-90 day) are a ubiquitous feature in the surface flow, and are
consistent with wind-forced Kelvin waves from both the eastern equatorial
Indian Ocean and the south coast of Java. Using a relationship with surface
velocity from three contemporaneous ADCP surveys, we approximate surface (
0-100 m) volume transport fluctuations through four of the main exit passag
es. The amplitude of the total surface transport variation through these pa
ssages is fairly uniform, ranging from 10-15 Sv.