The Indonesian seas and their role in the coupled ocean-climate system

TitleThe Indonesian seas and their role in the coupled ocean-climate system
Publication TypeJournal Article
Year of Publication2014
AuthorsSprintall J, Gordon A.L, Koch-Larrouy A., Lee T., Potemra J.T, Pujiana K., Wijffels S.E
JournalNature Geoscience
Volume7
Pagination487-492
Date Published2014/07
Type of ArticleArticle
ISBN Number1752-0894
Accession NumberWOS:000338832700007
Keywordscirculation; el-nino; exchange; Makassar Strait; pacific; throughflow; transport; tropical indian-ocean; variability; water mass transformation
Abstract

The Indonesian seas represent the only pathway that connects different ocean basins in the tropics, and therefore play a pivotal role in the coupled ocean and climate system. Here, water flows from the Pacific to the Indian Ocean through a series of narrow straits. The throughflow is characterized by strong velocities at water depths of about 100 m, with more minor contributions from surface flow than previously thought. A synthesis of observational data and model simulations indicates that the temperature, salinity and velocity depth profiles of the Indonesian throughflow are determined by intense vertical mixing within the Indonesian seas. This mixing results in the net upwelling of thermocline water in the Indonesian seas, which in turn lowers sea surface temperatures in this region by about 0.5 degrees C, with implications for precipitation and air-sea heat flux. Moreover, the depth and velocity of the core of the Indonesian throughflow has varied with the El Nino/Southern Oscillation and Indian Ocean Dipole on interannual to decadal timescales. Specifically, the throughflow slows and shoals during El Nino events. Changes in the Indonesian throughflow alter surface and subsurface heat content and sea level in the Indian Ocean between 10 and 15 degrees S. We conclude that inter-ocean exchange through the Indonesian seas serves as a feedback modulating the regional precipitation and wind patterns.

DOI10.1038/ngeo2188
Short TitleNat. Geosci.
Student Publication: 
No