The linear trends in oceanic temperature from 1960 to
1999 are estimated using the new Indian Ocean Thermal
Archive (IOTA), a compilation of historical temperature
profiles. Widespread surface warming is found, as in other
data sets, and reproduced in IPCC climate model
simulations for the 20th century. This warming is
particularly large in the subtropics, and extends down to
800 m around 40–50
S. Models suggest the deep-reaching
subtropical warming is related to a 0.5
southward shift of
the subtropical gyre driven by a strengthening of the
westerly winds, and associated with an upward trend in the
Southern Annular Mode index. In the tropics, IOTA shows
a subsurface cooling corresponding to a shoaling of the
thermocline and increasing vertical stratification. Most
models suggest this trend in the tropical Indian
thermocline is likely associated with the observed
weakening of the Pacific trade winds and transmitted to
the Indian Ocean by the Indonesian throughflow.

Full Article: http://www.agu.org/pubs/crossref/2007/2006GL028044.shtml

Last Updated: 2007-01-22