The Indonesian Throughflow as Represented in Climatological and Interannual Forcing Simulations of a High-Resolution Global Model

The exchange of waters from the Pacific into the Indian Ocean through the Indonesian seas is known as the Indonesian Throughflow (ITF). The ITF is part of the upper branch of the Meridional Overturning Circulation (MOC) and, as such, an integrant of the Global Climate System. An eddy-resolving global ocean model is being used to study the ITF and its variability. Firstly, an implementation of the Hybrid Coordinate Ocean Model (HYCOM), with 1/12° horizontal resolution and 32 Isopycnic layers, was run with only climatological forcing. The last ten years of a two decades run are then analyzed. The known circulation patterns are well represented and the outputs show no long term trends. Currently, another numerical simulation with interannual forcing is being run, from 1949 to the present. The results will be compared with those of the climatological run, concerning the ITF, its interdecadal variability, and also possible changes in indicators for the Indo-Pacific circulation, heat content and net transports.