Mechanisms of South Indian Ocean intraseasonal cooling

Vinayachandran, PN and Saji, NH (2008) Mechanisms of South Indian Ocean intraseasonal cooling. In: Geophysical Research Letters, 35 (23).

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Abstract

Intense cooling of the sea surface at intraseasonal time scales takes place in the southern tropical Indian Ocean during austral summer. Mechanisms that cause intraseasonal cooling are investigated using in situ observations by Argo floats, remote sensing data sets and simulation using a high resolution ocean general circulation model of the Indian Ocean. Temperature profiles from Argo floats within the cooling region show evidences for the entrainment of cool thermocline water into the mixed layer. The cooling events are accompanied by an increase in sea surface chlorophyll concentration which provides additional evidence for entrainment. The Indian Ocean model reproduces intraseasonal cooling events and demonstrates that mixed layer cooling originate from vertical processes at the base of the mixed layer for certain events. The air-sea flux tends to be the dominant cooling mechanism when the thermocline is deep and mixed layer is thick whereas entrainment dominates when the thermocline is shallow. Citation: Vinayachandran, P. N., and N. H. Saji (2008), Mechanisms of South Indian Ocean intraseasonal cooling, Geophys. Res. Lett., 35, L23607, doi: 10.1029/2008GL035733.

Item Type:	Journal Article
Publication:	Geophysical Research Letters
Publisher:	American Geophysical Union.
Additional Information:	Copyright of this article belongs to American Geophysical Union.
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	20 Aug 2009 12:29
Last Modified:	19 Sep 2010 04:58
URI:	http://eprints.iisc.ac.in/id/eprint/17842

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