Srivastava, A. K. and Ram, K. and Singh, Sachchidanand and Kumar, Sanjeev and Tiwari, S. (2015) Aerosol optical properties and radiative effects over Manora Peak in the Himalayan foothills: seasonal variability and role of transported aerosols. Science of the Total Environment, 502. 287 -295. ISSN 0048-9697

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Abstract

The higher altitude regions of Himalayas and Tibetan Plateau are influenced by the dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. In this study, we present impacts of advection of polluted air masses of natural and anthropogenic emissions, on aerosol optical and radiative properties at Manora Peak (similar to 2000 m amsl) in central Himalaya over a period of more than two years (February 2006-May 2008). We used the most updated and comprehensive data of chemical and optical properties available in one of the most climatically sensitive region, the Himalaya, to estimate atmospheric radiative forcing and heating rate. Aerosol optical depth (ADD) was found to vary from 0.04 to 0.45 with significantly higher values in summer mainly due to an increase in mineral dust and biomass burning aerosols due to transport. In contrast, single scattering albedo (SSA) varied from 0.74 to 0.88 with relatively lower values during summer, suggesting an increase in absorbing BC and mineral dust aerosols. As a result, a large positive atmospheric radiative forcing (about 28 5 Wm(-2)) and high values of corresponding heating rate (0.80 +/- 0.14 Kday(-1)) has been found during summer. During the entire observation period, radiative forcing at the top of the atmosphere varied from 2 to +14 Wm(-2) and from -3 to -50 Wm(-2) at the surface whereas atmospheric forcing was in the range of 3 to 65 Wm(-2) resulting in a heating rate of 0.1-1.8 Kday(-1).

Item Type:	Article
Uncontrolled Keywords:	Aerosol composition Aerosol optical properties Radiative forcing Atmospheric heating rate Himalayan foothills Indo-Gangetic plain
Subjects:	General Science
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	15 Sep 2016 07:16
Last Modified:	15 Sep 2016 07:16
URI:	http://npl.csircentral.net/id/eprint/1705

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