Cool Indonesian throughflow as a consequence of restricted surface layer flow

LDEO Publication: 
Publication Type  Journal Article
Year of Publication  2003
Authors  Gordon, A. L.; Susanto, R. D.; Vranes, K.
Journal Title  Nature
Volume  425
Issue  6960
Pages  824-828
Journal Date  Oct 23
ISBN Number  0028-0836
Accession Number  ISI:000186118500042
LDEO Publication Number  6508
Key Words  indian-ocean; makassar strait; heat-transport; climate system; pacific; circulation; budget; water; fluxes; seas

Approximately 10 million m(3) s(-1) of water flow from the Pacific Ocean into the Indian Ocean through the Indonesian seas(1). Within the Makassar Strait, the primary pathway of the flow(2), the Indonesian throughflow is far cooler than estimated earlier, as pointed out recently on the basis of ocean current and temperature measurements(3,4). Here we analyse ocean current and stratification data along with satellite-derived wind measurements, and find that during the boreal winter monsoon, the wind drives buoyant, low-salinity Java Sea surface water into the southern Makassar Strait, creating a northward pressure gradient in the surface layer of the strait. This surface layer 'freshwater plug' inhibits the warm surface water from the Pacific Ocean from flowing southward into the Indian Ocean, leading to a cooler Indian Ocean sea surface(5-7), which in turnmay weaken the Asian monsoon(8). The summer wind reversal eliminates the obstructing pressure gradient, by transferring more- saline Banda Sea surface water into the southern Makassar Strait. The coupling of the southeast Asian freshwater budget to the Pacific and Indian Ocean surface temperatures by the proposed mechanism may represent an important negative feedback within the climate system.


735METimes Cited:19Cited References Count:29

URL  <Go to ISI>://000186118500042
DOI  Doi 10.1038/Nature02038