Aerosol black carbon characteristics over a high-altitude Western Ghats location in Southern India
Aerosol black carbon (BC) mass concentrations were continuously monitored over a period of 2 years (April 2010 to May 2012) from a high-altitude location Ooty in the Nilgiris Mountain range in southern India to characterize the distinct nature of absorbing aerosols and their seasonality. Despit...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-10-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/32/1361/2014/angeo-32-1361-2014.pdf |
| Summary: | Aerosol black carbon
(BC) mass concentrations were continuously monitored over a period
of 2 years (April 2010 to May 2012) from a high-altitude location Ooty in the
Nilgiris Mountain range in southern India to characterize the distinct nature
of absorbing aerosols and their seasonality. Despite being remote and
sparsely inhabited, BC concentrations showed significant seasonality with
higher values (~ 0.96 ± 0.35 μg m<sup>−3</sup>) in summer
(March to May), attributed to increased vertical transport of effluents in
the upwind valley regions, which might have been confined to the surrounding
valley regions within the very shallow winter boundary layer. The local
atmospheric boundary layer (ABL) influence in summer was further modulated by
the long-range transported aerosols from the eastern locations of Ooty.
During monsoon (June–August), the concentrations were far reduced
(~ 0.23 ± 0.06 μg m<sup>−3</sup>) due to intense
precipitation. Diurnal variations were found conspicuous mainly during summer
season associated with local ABL. The spectral absorption coefficients
(α<sub>abs</sub>) depicted, in general, flatter distribution
(mostly < 1.0 for more than 85% of daily mean values),
suggesting the relative dominance of fossil fuel combustion, though showed
marginal seasonal change with higher values of α<sub>abs</sub> in
summer. |
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| ISSN: | 0992-7689 1432-0576 |