Arlindo Circulation

The Arlindo Circulation field work includes: time series measurement at current meter moorings with ADCP and Aanderaa RCM-8 current meters and temperature pod (T-Pods); CTD/CFC tracer oceanographic stations. CTD and CFC stations were obtained at the mooring sites (yo-yo repeat stations) and along an east-west Flores - Banda Sea section to augment spatially and temporally, the 1993/94 Arlindo Mixing coverage. The research will be carried out by A. Gordon D. Pillsbury, A. Ffield, R. Fine.

Arlindo circulation has two other components. These are bottom-moored Inverted Echo Sounder with pressure sensors (PIES); and shallow pressure gauges. The PIES research is supervised by S. Garzoli; the shallow pressure gauge research by N. Bray . The PIES provides a time series the mean temperature and pressure of the water column, monitoring changes in thermocline depth and variations in the along pressure gradient in the Makassar Strait. An array of seven shallow (about 10 meters depth) gauges will be deployed in October or November 1995 to monitor fluctuations in the sea level slope in the Lombok Strait, Timor Strait, Ombai Strait (between Alor and Timor), and spanning the strait between Sumba and Sumbawa.

A 13 to 14 month deployment will not span an entire ENSO period. The data set will no doubt represent a specific phase of ENSO. The CTD coverage from Arlindo Mixing and Arlindo Circulation will allow comparison of stratification for a nearly a four year period, normally enough to have good chance of spanning an entire cycle, though the prolonged El Nino since 1991 has not been typical. However, Arlindo circulation will provide a base for long term monitoring, which will eventually capture the ENSO phases. Both shallow gauges and PIES if calibrated properly again transport measures of Arlindo, may prove effective means of long term monitoring (Phase III objective of Arlindo).

Lamont-Doherty Earth Observatory of Columbia University