Numerical Simulation Of The Indonesian Throughflow With A Coupled GCM

The Indonesian Throughflow (ITF) is analyzed in a numerical simulation with a coupled ocean-atmosphere model. The model, developed in the IAP/LASG, has been integrated for 300 years. We study the data of 100 years from the 101st model year to the 200th year. The simulated annual mean, seasonal cycle, and interannual variation of ITF transport agree well with the observations and other simulations. The Makassar and the Maluku Strait are the primary pathway of the ITF . The seasonal cycle of ITF is decided by the top layer current who is driven by the monsoon. During the boreal winter northwest monsoon , the wind drives buoyant, low-salinity Java sea surface water into the southern Makassar Strait, resulting a northward pressure gradient in the surface layer of the strait. This inhibits the warm surface water from the Pacific Ocean from flowing southward . During the boreal summer southeast monsoon, the wind eliminates the pressure gradient, by transferring more-saline Banda sea surface water into the southern Makassar Strait. Then the ITF can flow southward into the Indian Ocean. The interannual cycle of ITF is caused by the interannual variation of tropical circulation, and it is contributed by the Pacific Ocean and the Indian Ocean.