Modification of the Stratification and Velocity Profile within the Straits and Seas of the Indonesian Archipelago

The long-term goal of this research is to understand the circulation and mixing within the Indonesian Seas associated with topographic configuration, monsoon-driven sea-air flux of momentum and buoyancy, and tides. The objectives of this project are as follows: (1) to utilize existing in situ data (XBT/XCTD, CTD, LADCP, mooring time series, tide gauge records) and satellite data (TRMM, SAR, SST, scatterometer, altimeter) to advance the study of the spatial and temporal scales of topographically and tidally linked circulation, sea-air fluxes, mixing, and internal wave phenomenon within the Indonesian Seas; (2) to develop a collaborative study of the regional variability of meso- and sub-mesoscale processes and ocean strait dynamics within the Indonesian Seas, centered upon field observations. The in situ and satellite data were analyzed to identify the regions where the processes controlling the regional scale circulation, mixing, and ocean-atmosphere interactions would be most evident. The Seram Sea in the northeastern Indonesian Seas was identified as the location that is most revealing of the processes that impact the heat and freshwater inventories within the Indonesian Seas, and therefore the linkage by sea-air fluxes to the larger scale climate system. In the eastern Indonesian Seas the precipitation time series reveals the large variability that impacts the region annually and interannually. The anomaly of the precipitation time series reveals the minimum rainfall routinely observed each year during the southeast monsoon, June-July-August, and the association of El Nino years with droughts (1983, 1998) in the region. The Sea Surface Temperatures (SSTs) in the eastern Indonesian Seas, for example in the Seram Sea, reveal the relatively dramatic drop to cold SSTs during the windy southeast monsoon, June-July-August, and the association of the coldest monsoon seasons with El Nino years.