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Variation between near-surface and columnar aerosol characteristics during the winter and summer at Delhi in the Indo-Gangetic Basin

Srivastava, AK and Singh, S and Tiwari, S and Kanawade, VP and Bisht, DS (2012) Variation between near-surface and columnar aerosol characteristics during the winter and summer at Delhi in the Indo-Gangetic Basin. Journal of Atmospheric and Solar-Terrestrial Physics, 77. pp. 57-66.

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Abstract

Aerosol characteristics were studied over Delhi, a typical urban station in the Ganga basin in Northern India, during two contrasting weather conditions: winter and summer, to explain the changes in columnar and surface aerosol characteristics with the help of ground based measurements and CALIPSO satellite data. The near-surface mean aerosol mass concentrations of PM 10 and PM 2.5 (±standard deviation) were observed to be ~200 (±24) and 118 (±33)μgm -3, respectively, during the winter and ~168 (±31) and 55 (±12)μgm -3, respectively, during the summer. PM 2.5 was found to be about two times higher than the PM 10 concentration during the winter period. Aerosol mass size distribution showed bi-modal nature during both the periods, with relative dominance of fine-particle mass concentrations during the winter, having low R eff value (0.63±0.05μm) and coarse-particle mass concentrations during the summer, having large R eff value (1.52±0.60μm). The concurrent measurement of columnar aerosol optical depth (AOD) showed high values (>0.60 at 500nm) during both the periods. The à ngström exponent (α) over the station, however, also suggests relatively large contribution of fine-mode particles during the winter (α~1.02) and coarse-mode dust particles during the summer (α~0.51). The observed features in the surface and columnar measured aerosol characteristics during two different seasons are explained using the vertical winds coupled with the vertical profile of aerosols.

Item Type: Article
Additional Information: Copyright of this article belongs to Elsevier.
Uncontrolled Keywords: Aerosol characteristics; Aerosol mass; Aerosol mass concentration; Aerosol optical depth; Aerosol optical depths; CALIPSO; Dust particle; Fine particles; Fine-mode particles; Ganga basin; Ground based measurement; Indo-Gangetic basin; Mass concentration; Near-surface; Satellite data; Standard deviation; Typical urban; Vertical profile; Vertical wind; Weather conditions, Geophysics; Planetary surface analysis, Atmospheric aerosols
Subjects: Meteorology and Climatology
Depositing User: IITM Library
Date Deposited: 21 Dec 2013 07:17
Last Modified: 21 Dec 2013 07:17
URI: http://moeseprints.incois.gov.in/id/eprint/527

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