Open Access Digital Repository of Ministry of Earth Sciences, Government of India

The influence of a south asian dust storm on aerosol radiative forcing at a high-altitude station in central Himalayas

Srivastava, AK and Pant, P and Hegde, P and Singh, S and Dumka, UC and Naja, M and Singh, N and Bhavanikumar, Y (2011) 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.

Full text not available from this repository. (Request a copy)

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 significantly 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 optical 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

Item Type: Article
Additional Information: Copyright of this article belongs to Taylor & Francis.
Uncontrolled Keywords: Above ground level; Aerosol index; Aerosol optical depths; Aerosol radiative forcing; Air mass; Asian dust storm; Atmospheric radiative transfer; Back trajectory analysis; Discrete ordinates; Dust aerosols; Dust layer; High altitude; Himalayas; Lower atmosphere; Maximum values; Optical properties of aerosols; Santa Barbara; Sun photometers; Thar Desert; Top of atmospheres, Atmospheric aerosols; Atmospheric radiation; Dust; Optical properties; Optical radar; Radiative transfer; Storms, Atmospheric movements, aerosol; air mass; backscatter; dust storm; lidar; long range transport; observational method; optical depth; photometer; radiative forcing; radiative transfer; spectral analysis; top of atmosphere, Himalayas; Thar Desert
Subjects: Meteorology and Climatology
Depositing User: IITM Library
Date Deposited: 29 Oct 2014 10:09
Last Modified: 29 Oct 2014 10:09
URI: http://moeseprints.incois.gov.in/id/eprint/642

Actions (login required)

View Item View Item