|
Titel |
Pre-monsoon aerosol characteristics over the Indo-Gangetic Basin: implications to climatic impact |
VerfasserIn |
A. K. Srivastava, S. Tiwari, P. C. S. Devara, D. S. Bisht, Manoj K. Srivastava, S. N. Tripathi, P. Goloub, B. N. Holben |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 29, no. 5 ; Nr. 29, no. 5 (2011-05-11), S.789-804 |
Datensatznummer |
250017013
|
Publikation (Nr.) |
copernicus.org/angeo-29-789-2011.pdf |
|
|
|
Zusammenfassung |
Sun/sky radiometer observations over the Indo-Gangetic Basin (IGB) region
during pre-monsoon (from April–June 2009) have been processed to analyze
various aerosol characteristics in the central and eastern IGB region,
represented by Kanpur and Gandhi College, respectively, and their impacts on
climate in terms of radiative forcing. Monthly mean aerosol optical depth
(AOD at 500 nm) and corresponding Angstrom Exponent (AE at 440–870 nm, given
within the brackets) was observed to be about 0.50 (0.49) and 0.51 (0.65) in
April, 0.65 (0.74) and 0.67 (0.91) in May and 0.69 (0.45) and 0.77 (0.71) in
June at Kanpur and Gandhi College, respectively. Results show a positive
gradient in AOD and AE from central to eastern IGB region with the
advancement of the pre-monsoon, which may be caused due to diverse
geographical location of the stations having different meteorological
conditions and emission sources. Relatively lower SSA was observed at the
eastern IGB (0.89) than the central IGB (0.92) region during the period,
which suggests relative dominance of absorbing aerosols at the eastern IGB
as compared to central IGB region. The absorbing aerosol optical properties
over the station suggest that the atmospheric absorption over central IGB
region is mainly due to dominance of coarse-mode dust particles; however,
absorption over eastern IGB region is mainly due to dominance of
fine-particle pollution. The derived properties from sun/sky radiometer
during pre-monsoon period are used in a radiative-transfer model to estimate
aerosol radiative forcing at the top-of-the atmosphere (TOA) and at the
surface over the IGB region. Relatively large TOA and surface cooling was
observed at the eastern IGB as compared to the central IGB region. This
translates into large heating of the atmosphere ranging from 0.45 to 0.55 K day−1
at Kanpur and from 0.45 to 0.59 K day−1 at Gandhi College. |
|
|
Teil von |
|
|
|
|
|
|