Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent
The unique geographical diversity and rapid urbanization across the Indian subcontinent give rise to large-scale spatiotemporal variations in urban heating and air emissions. The complex relationship between geophysical parameters and anthropogenic activity is vital in understanding the urban enviro...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-05-01
|
| Series: | Remote Sensing |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-4292/15/10/2681 |
| _version_ | 1797598447127232512 |
|---|---|
| author | Trisha Chakraborty Debashish Das Rafiq Hamdi Ansar Khan Dev Niyogi |
| author_facet | Trisha Chakraborty Debashish Das Rafiq Hamdi Ansar Khan Dev Niyogi |
| author_sort | Trisha Chakraborty |
| collection | DOAJ |
| description | The unique geographical diversity and rapid urbanization across the Indian subcontinent give rise to large-scale spatiotemporal variations in urban heating and air emissions. The complex relationship between geophysical parameters and anthropogenic activity is vital in understanding the urban environment. This study analyses the characteristics of heating events using aerosol optical depth (AOD) level variability, across 43 urban agglomerations (UAs) with populations of a million or more, along with 13 industrial districts (IDs), and 14 biosphere reserves (BRs) in the Indian sub-continent. Pre-monsoon average surface heating was highest in the urban areas of the western (42 °C), central (41.9 °C), and southern parts (40 °C) of the Indian subcontinent. High concentration of AOD in the eastern part of the Indo-Gangetic Plain including the megacity: Kolkata (decadal average 0.708) was noted relative to other UAs over time. The statistically significant negative correlation (−0.51) between land surface temperature (LST) and AOD in urban areas during pre-monsoon time illustrates how aerosol loading impacts the surface radiation and has a net effect of reducing surface temperatures. Notable interannual variability was noted with, the pre-monsoon LST dropping in 2020 across most of the selected urban regions (approx. 89% urban clusters) while it was high in 2019 (for approx. 92% urban clusters) in the pre-monsoon season. The results indicate complex variability and correlations between LST and urban aerosol at large scales across the Indian subcontinent. These large-scale observations suggest a need for more in-depth analysis at city scales to understand the interplay and combined variability between physical and anthropogenic atmospheric parameters in mesoscale and microscale climates. |
| first_indexed | 2024-03-11T03:21:21Z |
| format | Article |
| id | doaj.art-540cb891510a44e09cb7df40be276689 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-11T03:21:21Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-540cb891510a44e09cb7df40be2766892023-11-18T03:08:40ZengMDPI AGRemote Sensing2072-42922023-05-011510268110.3390/rs15102681Large-Scale Urban Heating and Pollution Domes over the Indian SubcontinentTrisha Chakraborty0Debashish Das1Rafiq Hamdi2Ansar Khan3Dev Niyogi4School of Environmental Studies, Jadavpur University, Kolkata 700032, IndiaDepartment of Architecture, Jadavpur University, Kolkata 700032, IndiaRoyal Meteorological Institute of Belgium, 1180 Bruxelles, BelgiumDepartment of Geography, Lalbaba College, University of Calcutta, Howrah 711201, IndiaDepartment of Geological (Earth and Planetary) Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78759, USAThe unique geographical diversity and rapid urbanization across the Indian subcontinent give rise to large-scale spatiotemporal variations in urban heating and air emissions. The complex relationship between geophysical parameters and anthropogenic activity is vital in understanding the urban environment. This study analyses the characteristics of heating events using aerosol optical depth (AOD) level variability, across 43 urban agglomerations (UAs) with populations of a million or more, along with 13 industrial districts (IDs), and 14 biosphere reserves (BRs) in the Indian sub-continent. Pre-monsoon average surface heating was highest in the urban areas of the western (42 °C), central (41.9 °C), and southern parts (40 °C) of the Indian subcontinent. High concentration of AOD in the eastern part of the Indo-Gangetic Plain including the megacity: Kolkata (decadal average 0.708) was noted relative to other UAs over time. The statistically significant negative correlation (−0.51) between land surface temperature (LST) and AOD in urban areas during pre-monsoon time illustrates how aerosol loading impacts the surface radiation and has a net effect of reducing surface temperatures. Notable interannual variability was noted with, the pre-monsoon LST dropping in 2020 across most of the selected urban regions (approx. 89% urban clusters) while it was high in 2019 (for approx. 92% urban clusters) in the pre-monsoon season. The results indicate complex variability and correlations between LST and urban aerosol at large scales across the Indian subcontinent. These large-scale observations suggest a need for more in-depth analysis at city scales to understand the interplay and combined variability between physical and anthropogenic atmospheric parameters in mesoscale and microscale climates.https://www.mdpi.com/2072-4292/15/10/2681land surface temperatureaerosol optical depthurban agglomerationindustrial districtsbiosphere reserve |
| spellingShingle | Trisha Chakraborty Debashish Das Rafiq Hamdi Ansar Khan Dev Niyogi Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent Remote Sensing land surface temperature aerosol optical depth urban agglomeration industrial districts biosphere reserve |
| title | Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent |
| title_full | Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent |
| title_fullStr | Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent |
| title_full_unstemmed | Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent |
| title_short | Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent |
| title_sort | large scale urban heating and pollution domes over the indian subcontinent |
| topic | land surface temperature aerosol optical depth urban agglomeration industrial districts biosphere reserve |
| url | https://www.mdpi.com/2072-4292/15/10/2681 |
| work_keys_str_mv | AT trishachakraborty largescaleurbanheatingandpollutiondomesovertheindiansubcontinent AT debashishdas largescaleurbanheatingandpollutiondomesovertheindiansubcontinent AT rafiqhamdi largescaleurbanheatingandpollutiondomesovertheindiansubcontinent AT ansarkhan largescaleurbanheatingandpollutiondomesovertheindiansubcontinent AT devniyogi largescaleurbanheatingandpollutiondomesovertheindiansubcontinent |