The Indonesian Throughflow is an ocean current that transports water between the Pacific Ocean and the Indian Ocean through the Indonesian Archipelago. In the north, the current enters the Indonesian seas through the Makassar Strait and Malacca Straits. The Indonesian seas function like a basin, and the Throughflow continues southerly and exits through the Lombok Strait, Ombai Strait and Timor Passage. The direction of the transport is strongly dependent on seasonal and annual climate, although the total net annual transport is mostly southward from the Pacific Ocean into the Indian Ocean.
In the available data, an annual net northerly directed transport through the southern boundaries was only seen in 1998, and this can be explained as a post El Niño effect. However, it also directly illustrate the relation between the global climate and the Indonesian Throughflow.
An important feature of the Indonesian Throughflow is that because the water in the western equatorial Pacific Ocean has a higher temperature and lower salinity than the water in the Indian Ocean, the Throughflow transports large amounts of relatively warm and fresh water to the Indian Ocean. When the Indonesian Throughflow (through Lombok Strait and the Timor Passage) enters the Indian Ocean it is advected towards Africa within the Indian South Equatorial Current. Here it eventually exits the Indian Ocean with the Agulhas Current around South Africa into the Atlantic Ocean. So the Indonesian Throughflow transports a significant amount of Pacific Ocean heat into the southwest Indian Ocean, which is approximately 10,000 km (6,200 mi) away from the Lombok Strait.Indonesian Throughflow - Marine Research
