Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals
ABSTRACT Daily measurements of aerosol optical depth ( τ ) and Ångstrom wavelength exponent ( α ) acquired from Aerosol Robotic Network (AERONET) and Moderate Resolution Imaging Spectrometer (MODIS) are analysed over Lahore – an urban city of Pakistan (period: 2010–2014) to investigate contribution...
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crwiley:10.1002/joc.5230 2024-06-02T07:54:22+00:00 Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals Zafar, Qudsia Zafar, Sidra Holben, Brent GCISC 2017 http://dx.doi.org/10.1002/joc.5230 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjoc.5230 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/joc.5230 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor International Journal of Climatology volume 38, issue 2, page 1022-1040 ISSN 0899-8418 1097-0088 journal-article 2017 crwiley https://doi.org/10.1002/joc.5230 2024-05-03T10:48:16Z ABSTRACT Daily measurements of aerosol optical depth ( τ ) and Ångstrom wavelength exponent ( α ) acquired from Aerosol Robotic Network (AERONET) and Moderate Resolution Imaging Spectrometer (MODIS) are analysed over Lahore – an urban city of Pakistan (period: 2010–2014) to investigate contribution of different types of aerosols originating from both local and regional source locations. The obtained annual averages (mean ± standard deviation) for AERONET retrievals of τ (500 nm) and α (440–870 nm) are 0.68 ± 0.37 (0.08–2.91) and 0.99 ± 0.33 (0–1.8), respectively. Of all the sources, 61% are found within Pakistan, 11% in India, 19% in Afghanistan, 6% in Iran and 2% in Saudi Arabia with seasonal contributions of 35, 25, 23 and 17% in pre‐monsoon, monsoon, winter and post‐monsoon, respectively. The bimodal distributions of α show dominance of coarse‐mode particles during pre‐monsoon, fine‐mode particles during post‐monsoon and presence of both coarse‐mode and fine‐mode particles during winter and monsoon with winter showing more fine‐mode particles. Two broad classes of aerosols namely desert dust (DD) and biomass burning/urban industrial (BU) are identified with criteria, e.g. τ ≥ 0.3 and α ≤ 0.75 indicating presence of DD while τ ≥ 0.2 and α ≥ 1.15 indicating BU. The frequency of occurrence (FOO) of DD and BU aerosols is further identified by applying classification criteria over Aqua‐MODIS deep blue retrievals. The FOO identifies anthropogenic activity on‐going throughout the year, disrupted with DD aerosols only during pre‐monsoon and monsoon. The maximum dust activity is seen over Indo‐Gangetic plains (IGP) (localized maxima: 35–45%) and the Arabian peninsula (>55%) during pre‐monsoon, while maximum BU aerosols are found over IGP, central and south‐eastern plains of India and the state of Gujarat (localized maxima: >70%) in winter and post‐monsoon. Article in Journal/Newspaper Aerosol Robotic Network Wiley Online Library International Journal of Climatology 38 2 1022 1040 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
ABSTRACT Daily measurements of aerosol optical depth ( τ ) and Ångstrom wavelength exponent ( α ) acquired from Aerosol Robotic Network (AERONET) and Moderate Resolution Imaging Spectrometer (MODIS) are analysed over Lahore – an urban city of Pakistan (period: 2010–2014) to investigate contribution of different types of aerosols originating from both local and regional source locations. The obtained annual averages (mean ± standard deviation) for AERONET retrievals of τ (500 nm) and α (440–870 nm) are 0.68 ± 0.37 (0.08–2.91) and 0.99 ± 0.33 (0–1.8), respectively. Of all the sources, 61% are found within Pakistan, 11% in India, 19% in Afghanistan, 6% in Iran and 2% in Saudi Arabia with seasonal contributions of 35, 25, 23 and 17% in pre‐monsoon, monsoon, winter and post‐monsoon, respectively. The bimodal distributions of α show dominance of coarse‐mode particles during pre‐monsoon, fine‐mode particles during post‐monsoon and presence of both coarse‐mode and fine‐mode particles during winter and monsoon with winter showing more fine‐mode particles. Two broad classes of aerosols namely desert dust (DD) and biomass burning/urban industrial (BU) are identified with criteria, e.g. τ ≥ 0.3 and α ≤ 0.75 indicating presence of DD while τ ≥ 0.2 and α ≥ 1.15 indicating BU. The frequency of occurrence (FOO) of DD and BU aerosols is further identified by applying classification criteria over Aqua‐MODIS deep blue retrievals. The FOO identifies anthropogenic activity on‐going throughout the year, disrupted with DD aerosols only during pre‐monsoon and monsoon. The maximum dust activity is seen over Indo‐Gangetic plains (IGP) (localized maxima: 35–45%) and the Arabian peninsula (>55%) during pre‐monsoon, while maximum BU aerosols are found over IGP, central and south‐eastern plains of India and the state of Gujarat (localized maxima: >70%) in winter and post‐monsoon. |
author2 |
GCISC |
format |
Article in Journal/Newspaper |
author |
Zafar, Qudsia Zafar, Sidra Holben, Brent |
spellingShingle |
Zafar, Qudsia Zafar, Sidra Holben, Brent Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals |
author_facet |
Zafar, Qudsia Zafar, Sidra Holben, Brent |
author_sort |
Zafar, Qudsia |
title |
Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals |
title_short |
Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals |
title_full |
Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals |
title_fullStr |
Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals |
title_full_unstemmed |
Seasonal assessment and classification of aerosols transported to Lahore using AERONET and MODIS deep blue retrievals |
title_sort |
seasonal assessment and classification of aerosols transported to lahore using aeronet and modis deep blue retrievals |
publisher |
Wiley |
publishDate |
2017 |
url |
http://dx.doi.org/10.1002/joc.5230 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjoc.5230 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/joc.5230 |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
International Journal of Climatology volume 38, issue 2, page 1022-1040 ISSN 0899-8418 1097-0088 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/joc.5230 |
container_title |
International Journal of Climatology |
container_volume |
38 |
container_issue |
2 |
container_start_page |
1022 |
op_container_end_page |
1040 |
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1800755978894835712 |