Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter Seasons
Abstract In this study a Microtops II sunphotometer is used for the first time over Birtamode, a rapidly growing city located in the eastern Himalayan foothills of Nepal, to measure aerosol optical depth (AOD). The average AOD for the observation period (October 2018–February 2019) was 0.68 ± 0.39 w...
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| Format: | Article |
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Springer
2022-03-01
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| Series: | Aerosol and Air Quality Research |
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| Online Access: | https://doi.org/10.4209/aaqr.210152 |
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| author | Sishir Dahal Dipesh Rupakheti Ram Kumar Sharma Binod Kumar Bhattarai Bhupesh Adhikary |
| author_facet | Sishir Dahal Dipesh Rupakheti Ram Kumar Sharma Binod Kumar Bhattarai Bhupesh Adhikary |
| author_sort | Sishir Dahal |
| collection | DOAJ |
| description | Abstract In this study a Microtops II sunphotometer is used for the first time over Birtamode, a rapidly growing city located in the eastern Himalayan foothills of Nepal, to measure aerosol optical depth (AOD). The average AOD for the observation period (October 2018–February 2019) was 0.68 ± 0.39 with the post-monsoon season having a higher value (0.74 ± 0.43) compared to the winter season (0.60 ± 0.32). The Angstrom exponent (α) for post-monsoon and winter are found to be 1.08 ± 0.10 and 1.11 ± 0.16 respectively. During the monitoring period, the majority of AOD values (47%) are above 0.60, indicating moderately polluted conditions in the region. Anthropogenic, biomass burning, and mixed aerosols are identified as the prevalent aerosol types in the study region. The observed aerosol classification is also explained in terms of CAMS near-real-time model datasets. The AOD values retrieved by MODIS, VIIRS, Himawari-8, and CAMS show a good correlation with the observed Microtops AOD with R2 values ranging from 0.60 to 0.94. Moreover, different MODIS aerosol products (DB, DT, and combined DB-DT) are evaluated based on a comparison of Collection 6.1 AOD with the ground truth obtained from Microtops. The spatial distribution of AOD as observed by various satellites are compared and the vertical distribution of aerosol is also explained with the extinction coefficient provided by the CALIOP lidar onboard CALIPSO and aerosol types provided by CAMS. |
| format | Article |
| id | doaj-art-0b92381924644aa0b8c2773c808f8cf9 |
| institution | Kabale University |
| issn | 1680-8584 2071-1409 |
| language | English |
| publishDate | 2022-03-01 |
| publisher | Springer |
| record_format | Article |
| series | Aerosol and Air Quality Research |
| spelling | doaj-art-0b92381924644aa0b8c2773c808f8cf92025-02-09T12:17:04ZengSpringerAerosol and Air Quality Research1680-85842071-14092022-03-0122411910.4209/aaqr.210152Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter SeasonsSishir Dahal0Dipesh Rupakheti1Ram Kumar Sharma2Binod Kumar Bhattarai3Bhupesh Adhikary4International Centre for Integrated Mountain DevelopmentJiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and TechnologyDepartment of Applied Sciences and Chemical Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan UniversityDepartment of Applied Sciences and Chemical Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan UniversityInternational Centre for Integrated Mountain DevelopmentAbstract In this study a Microtops II sunphotometer is used for the first time over Birtamode, a rapidly growing city located in the eastern Himalayan foothills of Nepal, to measure aerosol optical depth (AOD). The average AOD for the observation period (October 2018–February 2019) was 0.68 ± 0.39 with the post-monsoon season having a higher value (0.74 ± 0.43) compared to the winter season (0.60 ± 0.32). The Angstrom exponent (α) for post-monsoon and winter are found to be 1.08 ± 0.10 and 1.11 ± 0.16 respectively. During the monitoring period, the majority of AOD values (47%) are above 0.60, indicating moderately polluted conditions in the region. Anthropogenic, biomass burning, and mixed aerosols are identified as the prevalent aerosol types in the study region. The observed aerosol classification is also explained in terms of CAMS near-real-time model datasets. The AOD values retrieved by MODIS, VIIRS, Himawari-8, and CAMS show a good correlation with the observed Microtops AOD with R2 values ranging from 0.60 to 0.94. Moreover, different MODIS aerosol products (DB, DT, and combined DB-DT) are evaluated based on a comparison of Collection 6.1 AOD with the ground truth obtained from Microtops. The spatial distribution of AOD as observed by various satellites are compared and the vertical distribution of aerosol is also explained with the extinction coefficient provided by the CALIOP lidar onboard CALIPSO and aerosol types provided by CAMS.https://doi.org/10.4209/aaqr.210152Microtops II sunphotometerMODISCAMSHimawari-8VIIRSCALIPSO |
| spellingShingle | Sishir Dahal Dipesh Rupakheti Ram Kumar Sharma Binod Kumar Bhattarai Bhupesh Adhikary Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter Seasons Aerosol and Air Quality Research Microtops II sunphotometer MODIS CAMS Himawari-8 VIIRS CALIPSO |
| title | Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter Seasons |
| title_full | Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter Seasons |
| title_fullStr | Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter Seasons |
| title_full_unstemmed | Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter Seasons |
| title_short | Aerosols over the Foothills of the Eastern Himalayan Region during Post-monsoon and Winter Seasons |
| title_sort | aerosols over the foothills of the eastern himalayan region during post monsoon and winter seasons |
| topic | Microtops II sunphotometer MODIS CAMS Himawari-8 VIIRS CALIPSO |
| url | https://doi.org/10.4209/aaqr.210152 |
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