Srivastava, Atul K. and Pant, P. and Hegde, P. and Singh, Sachchidanand and Dumka, U. C. and Naja, Manish and Singh, Narendra and Bhavanikumar, Y. (2010) The influence of a south Asian dust storm on aerosol radiative forcing at a high-altitude station in central Himalayas. International Journal of Remote Sensing , 32 (22). pp. 7827-7845. ISSN 0143-1161

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Abstract

The impact of long-range transported dust aerosols, originating from the Thar Desert region, to a high-altitude station in the central Himalayas was studied with the help of micro-pulse lidar (MPL) observations. A drastic change in lidar back-scatter profile was observed on a dust day as compared with that on a pre– dust day. The back-scatter coefficient on a dust day revealed that the dust layer peaked at an altitude ∼1300 m above ground level (AGL) and extended up to ∼3000 m AGL, with maximum value ∼3 × 10–5 m–1 sr–1 . Aerosol Index (AI) and air mass back-trajectory analysis substantiate the transport of dust aerosols from the far-off Thar Desert region to the experimental site. A significant effect of dust aerosols was also observed over the station on the spectral aerosol optical depths (AODs), measured using a Microtops-II Sunphotometer. It showed signif- icantly different spectral behaviour of AOD on a dust day as compared with that on a pre-dust day. The Ångström exponent (α) showed a marked decrease from 0.42 to 0.04 from the pre-dust day to the dust day. The aerosol radiative forcing estimated using the Santa Barbara DISORT (discrete ordinate radiative transfer) atmospheric radiative transfer (SBDART) model, in conjunction with the opti- cal properties of aerosol and cloud (OPAC) model, showed values of about –30, –45 and +15 W m–2 , respectively, at top-of-atmosphere (TOA), surface and in the atmosphere on the dust day. The positive atmosphere forcing caused an estimated heating of the lower atmosphere by ∼0.4 K day–1 .

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Taylor & Francis Group.
Subjects:	Imaging Science & Photographic Technology Remote Sensing
Divisions:	UNSPECIFIED
Depositing User:	Mr. Abhishek Yadav
Date Deposited:	16 Oct 2012 09:06
Last Modified:	16 Oct 2012 09:06
URI:	http://npl.csircentral.net/id/eprint/691

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