The sensitivity of the northern hemisphere summer mean meridional circulation to changes in the large scale eddy forcing

Goswami, BN (1985) The sensitivity of the northern hemisphere summer mean meridional circulation to changes in the large scale eddy forcing. In: Proceedings of the Indian Academy of Sciences - Earth & Planetary Sciences, 94 (3). pp. 219-235.

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Abstract

A zonally averaged version of the Goddard Laboratory for Atmospheric Sciences (GLAS) climate model is used to study the sensitivity of the northern hemisphere (NH) summer mean meridional circulation to changes in the large scale eddy forcing. A standard solution is obtained by prescribing the latent heating field and climatological horizontal transports of heat and momentum by the eddies. The radiative heating and surface fluxes are calculated by model parameterizations. This standard solution is compared with the results of several sensitivity studies. When the eddy forcing is reduced to 0.5 times or increased to 1.5 times the climatological values, the strength of the Ferrel cells decrease or increase proportionally. It is also seen that such changes in the eddy forcing can influence the strength of theNH Hadley cell significantly. Possible impact of such changes in the large scale eddy forcing on the monsoon circulation via changes in the Hadley circulation is discussed. Sensitivity experiments including only one component of eddy forcing at a time show that the eddy momentum fluxes seem to be more important in maintaining the Ferrel cells than the eddy heat fluxes. In the absence of the eddy heat fluxes, the observed eddy momentum fluxes alone produce subtropical westerly jets which are weaker than those in the standard solution. On the other hand, the observed eddy heat fluxes alone produce subtropical westerly jets which are stronger than those in the standard solution.

Item Type:	Journal Article
Publication:	Proceedings of the Indian Academy of Sciences - Earth & Planetary Sciences
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy of Sciences.
Keywords:	Symmetric model;eddy transports;sensitivity experiments.
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	19 Jan 2010 10:19
Last Modified:	19 Sep 2010 05:45
URI:	http://eprints.iisc.ac.in/id/eprint/23385

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