Direct radiative effect by brown carbon over the Indo-Gangetic Plain
The importance of light-absorbing organic aerosols, often called brown carbon (BrC), has become evident in recent years. However, there have been relatively few measurement-based estimates for the direct radiative effect of BrC so far. In earlier studies, the AErosol RObotic NETwork (AERONET)-measur...
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ftdoajarticles:oai:doaj.org/article:1d6afff9524049449016b6d6c81e99ff 2023-05-15T13:06:33+02:00 Direct radiative effect by brown carbon over the Indo-Gangetic Plain A. Arola G. L. Schuster M. R. A. Pitkänen O. Dubovik H. Kokkola A. V. Lindfors T. Mielonen T. Raatikainen S. Romakkaniemi S. N. Tripathi H. Lihavainen 2015-11-01T00:00:00Z https://doi.org/10.5194/acp-15-12731-2015 https://doaj.org/article/1d6afff9524049449016b6d6c81e99ff EN eng Copernicus Publications http://www.atmos-chem-phys.net/15/12731/2015/acp-15-12731-2015.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-15-12731-2015 https://doaj.org/article/1d6afff9524049449016b6d6c81e99ff Atmospheric Chemistry and Physics, Vol 15, Iss 22, Pp 12731-12740 (2015) Physics QC1-999 Chemistry QD1-999 article 2015 ftdoajarticles https://doi.org/10.5194/acp-15-12731-2015 2022-12-31T03:01:58Z The importance of light-absorbing organic aerosols, often called brown carbon (BrC), has become evident in recent years. However, there have been relatively few measurement-based estimates for the direct radiative effect of BrC so far. In earlier studies, the AErosol RObotic NETwork (AERONET)-measured aerosol absorption optical depth (AAOD) and absorption Angstrom exponent (AAE) were exploited. However, these two pieces of information are clearly not sufficient to separate properly carbonaceous aerosols from dust, while imaginary indices of refraction would contain more and better justified information for this purpose. This is first time that the direct radiative effect (DRE) of BrC is estimated by exploiting the AERONET-retrieved imaginary indices. We estimated it for four sites in the Indo-Gangetic Plain (IGP), Karachi, Lahore, Kanpur and Gandhi College. We found a distinct seasonality, which was generally similar among all the sites, but with slightly different strengths. The monthly warming effect up to 0.5 W m −2 takes place during the spring season. On the other hand, BrC results in an overall cooling effect in the winter season, which can reach levels close to −1 W m −2 . We then estimated similarly also the DRE of black carbon and total aerosol, in order to assess the relative significance of the BrC radiative effect in the radiative effects of other components. Even though BrC impact seems minor in this context, we demonstrated that it is not insignificant. Moreover, we demonstrated that it is crucial to perform spectrally resolved radiative transfer calculations to obtain good estimates for the DRE of BrC. Article in Journal/Newspaper Aerosol Robotic Network Directory of Open Access Journals: DOAJ Articles Atmospheric Chemistry and Physics 15 22 12731 12740 |
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Directory of Open Access Journals: DOAJ Articles |
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Physics QC1-999 Chemistry QD1-999 |
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Physics QC1-999 Chemistry QD1-999 A. Arola G. L. Schuster M. R. A. Pitkänen O. Dubovik H. Kokkola A. V. Lindfors T. Mielonen T. Raatikainen S. Romakkaniemi S. N. Tripathi H. Lihavainen Direct radiative effect by brown carbon over the Indo-Gangetic Plain |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
The importance of light-absorbing organic aerosols, often called brown carbon (BrC), has become evident in recent years. However, there have been relatively few measurement-based estimates for the direct radiative effect of BrC so far. In earlier studies, the AErosol RObotic NETwork (AERONET)-measured aerosol absorption optical depth (AAOD) and absorption Angstrom exponent (AAE) were exploited. However, these two pieces of information are clearly not sufficient to separate properly carbonaceous aerosols from dust, while imaginary indices of refraction would contain more and better justified information for this purpose. This is first time that the direct radiative effect (DRE) of BrC is estimated by exploiting the AERONET-retrieved imaginary indices. We estimated it for four sites in the Indo-Gangetic Plain (IGP), Karachi, Lahore, Kanpur and Gandhi College. We found a distinct seasonality, which was generally similar among all the sites, but with slightly different strengths. The monthly warming effect up to 0.5 W m −2 takes place during the spring season. On the other hand, BrC results in an overall cooling effect in the winter season, which can reach levels close to −1 W m −2 . We then estimated similarly also the DRE of black carbon and total aerosol, in order to assess the relative significance of the BrC radiative effect in the radiative effects of other components. Even though BrC impact seems minor in this context, we demonstrated that it is not insignificant. Moreover, we demonstrated that it is crucial to perform spectrally resolved radiative transfer calculations to obtain good estimates for the DRE of BrC. |
format |
Article in Journal/Newspaper |
author |
A. Arola G. L. Schuster M. R. A. Pitkänen O. Dubovik H. Kokkola A. V. Lindfors T. Mielonen T. Raatikainen S. Romakkaniemi S. N. Tripathi H. Lihavainen |
author_facet |
A. Arola G. L. Schuster M. R. A. Pitkänen O. Dubovik H. Kokkola A. V. Lindfors T. Mielonen T. Raatikainen S. Romakkaniemi S. N. Tripathi H. Lihavainen |
author_sort |
A. Arola |
title |
Direct radiative effect by brown carbon over the Indo-Gangetic Plain |
title_short |
Direct radiative effect by brown carbon over the Indo-Gangetic Plain |
title_full |
Direct radiative effect by brown carbon over the Indo-Gangetic Plain |
title_fullStr |
Direct radiative effect by brown carbon over the Indo-Gangetic Plain |
title_full_unstemmed |
Direct radiative effect by brown carbon over the Indo-Gangetic Plain |
title_sort |
direct radiative effect by brown carbon over the indo-gangetic plain |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/acp-15-12731-2015 https://doaj.org/article/1d6afff9524049449016b6d6c81e99ff |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
Atmospheric Chemistry and Physics, Vol 15, Iss 22, Pp 12731-12740 (2015) |
op_relation |
http://www.atmos-chem-phys.net/15/12731/2015/acp-15-12731-2015.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-15-12731-2015 https://doaj.org/article/1d6afff9524049449016b6d6c81e99ff |
op_doi |
https://doi.org/10.5194/acp-15-12731-2015 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
15 |
container_issue |
22 |
container_start_page |
12731 |
op_container_end_page |
12740 |
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1766010245542313984 |