Beegum, S. Naseema and Moorthy, K. Krishna and Gogoi, Mukunda M. and Babu, S. Suresh (2012) Multi-year investigations of aerosols from an island station, Port Blair, in the Bay of Bengal: climatology and source impacts. Annales Geophysicae, 30 (8). 1113-1127. ISSN 0992-7689

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Abstract

Long-term measurements of spectral aerosol optical depth (AOD) using multi-wavelength solar radiometer (MWR) for a period of seven years (from 2002 to 2008) from the island location, Port Blair (11.63A degrees N, 92.7A degrees E, PBR) in the Bay of Bengal (BoB), along with the concurrent measurements of the size distribution of near-surface aerosols, have been analyzed to delineate the climatological features of aerosols over eastern BoB. In order to identity the contribution of different aerosol types from distinct sources, concentration weighted trajectory (CWT) analysis has been employed. Climatologically, AODs increase from January to reach peak value of similar to 0.4 (at 500 nm) in March, followed by a weak decrease towards May. Over this general pattern, significant modulations of intra-seasonal time scales, caused by the changes in the relative strength of distinctively different sources, are noticed. The derivative (alpha') of the Angstrom wavelength exponent alpha in the wavelength domain, along with CWT analysis, are used to delineate the different important aerosol types that influence this remote island. Corresponding changes in the aerosol size distributions are inferred from the numerical inversion of the spectral AODs as well from (surface) measurements. The analyses revealed that advection plays a major role in modifying the aerosol properties over the remote island location, the potential sources contributing to the accumulation mode (coarse mode) aerosols over eastern BoB being the East Asia and South China regions (Indian mainland and the oceanic regions).

Item Type:	Article
Additional Information:	copyright for this article belongs to M/s European Geosciences Union
Subjects:	Geography, Physical Astronomy & Astrophysics
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	19 Aug 2026 11:08
Last Modified:	19 Aug 2026 11:08
URI:	https://npl.csircentral.net/id/eprint/3486

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