Amplification of South Asian haze by water vapour–aerosol interactions
<p>Air pollution and wintertime fog over South Asia is a major concern due to its significant implications for air quality, visibility and health. Using a regional climate model coupled with chemistry, we assess the contribution of the hygroscopic growth of aerosols (ambient–dry) to the total...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2020-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/20/14457/2020/acp-20-14457-2020.pdf |
| _version_ | 1819143062421504000 |
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| author | V. S. Nair F. Giorgi U. Keshav Hasyagar U. Keshav Hasyagar |
| author_facet | V. S. Nair F. Giorgi U. Keshav Hasyagar U. Keshav Hasyagar |
| author_sort | V. S. Nair |
| collection | DOAJ |
| description | <p>Air pollution and wintertime fog over South Asia is a
major concern due to its significant implications for air quality, visibility
and health. Using a regional climate model coupled with chemistry,
we assess the contribution of the hygroscopic growth of aerosols (ambient–dry)
to the total aerosol optical depth and demonstrate that the increased
surface cooling due to the hygroscopic effects of aerosols further increases
the humidity in the boundary layer and thus enhances the confinement of
pollutants through aerosol–boundary layer interactions. This positive
feedback mechanism plays an important role in the prevalence of wintertime
fog and poor air quality conditions over South Asia, where water vapour
contributes more than half of the aerosol optical depth. The
aerosol–boundary layer interactions lead to moistening of the boundary layer
and drying of the free troposphere, which amplifies the long-term trend in
relative humidity over the Indo-Gangetic Plain during winter. Hence, the
aerosol–water vapour interaction plays a decisive role in the formation and
maintenance of the wintertime fog conditions over South Asia, which
needs to be considered for planning mitigation strategies.</p> |
| first_indexed | 2024-12-22T12:20:16Z |
| format | Article |
| id | doaj.art-6d91affc111843ef974138d6fc7f3cab |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-22T12:20:16Z |
| publishDate | 2020-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-6d91affc111843ef974138d6fc7f3cab2022-12-21T18:26:00ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242020-11-0120144571447110.5194/acp-20-14457-2020Amplification of South Asian haze by water vapour–aerosol interactionsV. S. Nair0F. Giorgi1U. Keshav Hasyagar2U. Keshav Hasyagar3Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, Kerala, IndiaEarth System Physics, International Centre for Theoretical Physics, Trieste, ItalySpace Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, Kerala, IndiaDepartment of Physics, University of Kerala, Thiruvananthapuram, India<p>Air pollution and wintertime fog over South Asia is a major concern due to its significant implications for air quality, visibility and health. Using a regional climate model coupled with chemistry, we assess the contribution of the hygroscopic growth of aerosols (ambient–dry) to the total aerosol optical depth and demonstrate that the increased surface cooling due to the hygroscopic effects of aerosols further increases the humidity in the boundary layer and thus enhances the confinement of pollutants through aerosol–boundary layer interactions. This positive feedback mechanism plays an important role in the prevalence of wintertime fog and poor air quality conditions over South Asia, where water vapour contributes more than half of the aerosol optical depth. The aerosol–boundary layer interactions lead to moistening of the boundary layer and drying of the free troposphere, which amplifies the long-term trend in relative humidity over the Indo-Gangetic Plain during winter. Hence, the aerosol–water vapour interaction plays a decisive role in the formation and maintenance of the wintertime fog conditions over South Asia, which needs to be considered for planning mitigation strategies.</p>https://acp.copernicus.org/articles/20/14457/2020/acp-20-14457-2020.pdf |
| spellingShingle | V. S. Nair F. Giorgi U. Keshav Hasyagar U. Keshav Hasyagar Amplification of South Asian haze by water vapour–aerosol interactions Atmospheric Chemistry and Physics |
| title | Amplification of South Asian haze by water vapour–aerosol interactions |
| title_full | Amplification of South Asian haze by water vapour–aerosol interactions |
| title_fullStr | Amplification of South Asian haze by water vapour–aerosol interactions |
| title_full_unstemmed | Amplification of South Asian haze by water vapour–aerosol interactions |
| title_short | Amplification of South Asian haze by water vapour–aerosol interactions |
| title_sort | amplification of south asian haze by water vapour aerosol interactions |
| url | https://acp.copernicus.org/articles/20/14457/2020/acp-20-14457-2020.pdf |
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