Westward propagation of barrier layer formation in the 2006-07 Rossby wave event over the tropical southwest Indian Ocean

Abstract

A suite of satellite and in-situ observations are used to study ocean-atmospheric conditions over the tropical Southwest Indian Ocean (SWIO) during 2006-2007 when El Niño and an Indian Ocean dipole took place simultaneously. Argo profiles reveal a pronounced up-westward propagation of subsurface warming in the southern tropical Indian Ocean associated with Rossby waves traveling on the sloping thermocline. With the thermocline deepening by 60 m, a thick barrier layer forms and propagates with the Rossby wave, potentially contributing to the mixed layer warming. © 2009 by the American Geophysical Union.