Analysis of large-amplitude stratospheric mountain wave event observed from the AIRS and MLS sounders over the western Himalayan region

Kumar, Niranjan K and Ramkumar, TK and Krishnaiah, M (2012) Analysis of large-amplitude stratospheric mountain wave event observed from the AIRS and MLS sounders over the western Himalayan region. In: JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 117 .

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Abstract

Mountain waves in the stratosphere have been observed over elevated topographies using both nadir-looking and limb-viewing satellites. However, the characteristics of mountain waves generated over the Himalayan Mountain range and the adjacent Tibetan Plateau are relatively less explored. The present study reports on three-dimensional (3-D) properties of a mountain wave event that occurred over the western Himalayan region on 9 December 2008. Observations made by the Atmospheric Infrared Sounder on board the Aqua and Microwave Limb Sounder on board the Aura satellites are used to delineate the wave properties. The observed wave properties such as horizontal (lambda(x), lambda(y)) and vertical (lambda(z)) wavelengths are 276 km (zonal), 289 km (meridional), and 25 km, respectively. A good agreement is found between the observed and modeled/analyzed vertical wavelength for a stationary gravity wave determined using the Modern Era Retrospective Analysis for Research and Applications (MERRA) reanalysis winds. The analysis of both the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis and MERRA winds shows that the waves are primarily forced by strong flow across the topography. Using the 3-D properties of waves and the corrected temperature amplitudes, we estimated wave momentum fluxes of the order of similar to 0.05 Pa, which is in agreement with large-amplitude mountain wave events reported elsewhere. In this regard, the present study is considered to be very much informative to the gravity wave drag schemes employed in current general circulation models for this region.

Item Type:	Journal Article
Publication:	JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
Publisher:	AMER GEOPHYSICAL UNION
Additional Information:	Copyright for this article belongs to AMER GEOPHYSICAL UNION, WASHINGTON,
Department/Centre:	Division of Mechanical Sciences > Divecha Centre for Climate Change
Date Deposited:	19 Dec 2012 11:10
Last Modified:	19 Dec 2012 11:10
URI:	http://eprints.iisc.ac.in/id/eprint/45542

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