Large latitudinal gradients and temporal heterogeneity in aerosol black carbon and its mass mixing ratio over southern and northern oceans observed during a trans-continental cruise experiment
Extensive, and collocated measurements of the mass concentrations (M B ) of aerosol black carbon (BC) and (M T ) of composite aerosols were made over the Arabian Sea, tropical Indian Ocean and the Southern Ocean during a trans-continental cruise experiment. Our investigations show that M B remains e...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
American Geophysical Union
2005
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| Subjects: | |
| Online Access: | http://repository.ias.ac.in/17147/ http://repository.ias.ac.in/17147/1/340.pdf http://www.agu.org/pubs/crossref/2005./2005GL023267.shtml |
| Summary: | Extensive, and collocated measurements of the mass concentrations (M B ) of aerosol black carbon (BC) and (M T ) of composite aerosols were made over the Arabian Sea, tropical Indian Ocean and the Southern Ocean during a trans-continental cruise experiment. Our investigations show that M B remains extremely low (<50 ng m -3 ) and remarkably steady (in space and time) in the Southern Ocean (20°S to 56°S). In contrast, large latitudinal gradients exist north of ~20°S; M B increasing exponentially to reach as high as 2000 ng m -3 in the Arabian Sea (~8°N). Interestingly, the share of BC showed a distinctly different latitudinal variation, with a peak close to the equator and decreasing on either side. Large fluctuations were seen in M T over Southern Ocean associated with enhanced production of sea-salt aerosols in response to sea-surface wind speed. These spatio-temporal changes in M B and its mixing ratio have important implications to regional and global climate. |
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