Influences of the springtime northern Indian biomass burning over the central Himalayas

Kumar, Rajesh and Naja, Manish and Satheesh, SK and Ojha, N and Joshi, H and Sarangi, T and Pant, P and Dumka, UC and Hegde, P and Venkataramani, S (2011) Influences of the springtime northern Indian biomass burning over the central Himalayas. In: Journal of Geophysical Research, 116 .

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Abstract

The influences of the springtime northern Indian biomass burning are shown for the first time over the central Himalayas by using three years (2007-2009) of surface and space based observations along with a radiative transfer model. Near-surface ozone, black carbon (BC), spectral aerosol optical depths (AODs) and the meteorological parameters are measured at a high altitude site Nainital (29.37 degrees N, 79.45 degrees E, 1958 m amsl) located in the central Himalayas. The satellite observations include the MODIS derived fire counts and AOD (0.55 mu m), and OMI derived tropospheric column NO(2), ultraviolet aerosol index and single scattering albedo. MODIS fire counts and BC observations are used to identify the fire-impacted periods (372 h during 2007-2009) and hence the induced enhancements in surface BC, AOD (0.5 mu m) and ozone are estimated to be 1802 ng m(-3) (similar to 145%), 0.3 (similar to 150%) and 19 ppbv (similar to 34%) respectively. Large enhancements (53-100%) are also seen in the satellite derived parameters over a 2 degrees x 2 degrees region around Nainital. The present analysis highlights the northern Indian biomass burning induced cooling at the surface (-27 W m(-2)) and top of the atmosphere (-8 W m(-2)) in the lesser polluted high altitude regions of the central Himalayas. This cooling leads to an additional atmospheric warming of 19 W m(-2) and increases the lower atmospheric heating rate by 0.8 K day(-1). These biomass burning induced changes over the central Himalayan atmosphere during spring may also lead to enhanced short-wave absorption above clouds and might have an impact on the monsoonal rainfall.

Item Type:	Journal Article
Publication:	Journal of Geophysical Research
Publisher:	American Geophysical Union
Additional Information:	Copyright of this article belongs to American Geophysical Union.
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	04 Nov 2011 09:35
Last Modified:	04 Nov 2011 09:35
URI:	http://eprints.iisc.ac.in/id/eprint/41823

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