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| Titel |
Extremely large anthropogenic-aerosol contribution to total aerosol load over the Bay of Bengal during winter season |
| VerfasserIn |
D. G. Kaskaoutis, S. Kumar Kharol, P. R. Sinha, R. P. Singh, H. D. Kambezidis, A. Rani Sharma, K. V. S. Badarinath |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 14 ; Nr. 11, no. 14 (2011-07-21), S.7097-7117 |
| Datensatznummer |
250009934
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| Publikation (Nr.) |
 copernicus.org/acp-11-7097-2011.pdf |
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| Zusammenfassung |
| Ship-borne observations of spectral aerosol optical depth (AOD) have been
carried out over the entire Bay of Bengal (BoB) as part of the W-ICARB
cruise campaign during the period 27 December 2008–30 January 2009. The
results reveal a pronounced temporal and spatial variability in the optical
characteristics of aerosols mainly due to anthropogenic emissions and their
dispersion controlled by local meteorology. The highest aerosol amount, with
mean AOD500>0.4, being even above 1.0 on specific days, is found
close to the coastal regions in the western and northern parts of BoB. In
these regions the Ångström exponent is also found to be high (~1.2–1.25)
indicating transport of strong anthropogenic emissions from
continental regions, while very high AOD500 (0.39±0.07) and
α380–870 values (1.27±0.09) are found over the eastern
BoB. Except from the large α380–870 values, an indication of
strong fine-mode dominance is also observed from the AOD curvature, which is
negative in the vast majority of the cases, suggesting dominance of an
anthropogenic-pollution aerosol type. On the other hand, clean maritime
conditions are rather rare over the region, while the aerosol types are
further examined through a classification scheme based on the relationship
between α and dα. It was found that even for the same
α values the fine-mode dominance is larger for higher AODs
showing the strong continental influence over the marine environment of BoB.
Furthermore, there is also an evidence of aerosol-size growth under more
turbid conditions indicative of coagulation and/or humidification over
specific BoB regions. The results obtained using OPAC model show significant
fraction of soot aerosols (~6 %–8 %) over the eastern and
northwestern BoB, while coarse-mode sea salt particles are found to dominate
in the southern parts of BoB. |
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