IMOS - ABOS Deepwater Arrays (DA) Sub-facility, Indonesian Throughflow array, Ombai (ITFOMB) Mooring Platform

The Ombai deepwater mooring was first deployed on 2011-06-19 at (8.53 S, 125.09 E) in the Indonesian Throughflow.\n\nInstrumentation includes 150 kHz and 75kHz ADCPs, Seabird SBE39s, discrete current meters and Pressure Inverted Echo Sounders (PIES).\n\nThe mooring provides profile velocity data above 500m and point source velocity between 500m and 1200m (depth of controlling sill). Temperature and salinity data are collected for the entire water column.\n\nThe aim of IMOS Indonsian Throughflow moorings (Indoflow) is to sustainably and directly measure the leakage of Pacific thermocline and intermediate waters from the western equatorial Pacific into the South Indian Ocean. The Indonesian Passages represent an important 'choke point' of the global ocean overturning circulation and the climate system. The interannual to decadal variability of the size and depth distribution of the flow through this choke point remains a troublesome unknown. In particular, changes in this flow will reflect long term changes in the Pacific and Indian Ocean wind fields, particularly any change in the Walker Circulation, as predicted by coupled climate models forced by increasing Greenhouse Gas scenarios. Changes in the associated heat flux are also anticipated at the global oceans warm. The Indoflow array design is based on the more comprehensive INSTANT process study and is deemed the minimal required mooring array to monitor the Indonesian Throughflow. The Ombai Strait and Timor Passage Throughflow components comprise about 11Sv of the 14 Sv total interbasin exchange. The Indoflow array integrates with the AIMS NAOS shelf line, allowing estimates of the interbasin exchange to include the transport of very warm waters across the Australian North West Shelf. All moorings in the Timor Passage are located along a high precision swath line of the TOPEX/Jason satellite altimeter missions. These data will shed light on how best to exploit altimetric data over our shallow northern shelves, especially in data assimilating models.