What caused severe air pollution episode of November 2016 in New Delhi?. (1st February 2020)
- Record Type:
- Journal Article
- Title:
- What caused severe air pollution episode of November 2016 in New Delhi?. (1st February 2020)
- Main Title:
- What caused severe air pollution episode of November 2016 in New Delhi?
- Authors:
- Kanawade, V.P.
Srivastava, A.K.
Ram, K.
Asmi, E.
Vakkari, V.
Soni, V.K.
Varaprasad, V.
Sarangi, C. - Abstract:
- Abstract: In recent years, South Asia is experiencing severely degraded air quality, with particulate matter less than 2.5 μm (PM2.5 ) reaching unprecedented high levels. Here, we investigate a severe air pollution episode (SAPE) witnessed in New Delhi during 1–7 November 2016. This was a very unusual air pollution episode wherein air quality index exceeded >500 and was persistent for about a week encapsulating the entire Indo-Gangetic Plain (IGP). We demonstrate that a stagnant weather condition was the dominant cause of the SAPE. Mean concentration of PM2.5 in New Delhi before, during, and after the SAPE were 142 μg/m 3, 563 μg/m 3, and 240 μg/m 3, respectively. Satellite-based aerosol optical depth (AOD), ultraviolet-aerosol index (UV-AI) and surface carbon monoxide (CO) concentrations also showed significant enhancements over large locale spatially by about 50–70% during the SAPE. A large and simultaneous increase in UV-AI and CO downwind of a large number of fire hotspots (Punjab and Haryana) is a clear indication of biomass burning aerosols. Analysis of absorption Ångström exponent further substantiates this finding, showing a large fraction of light absorbing carbonaceous-type aerosols. Radiosonde observations clearly showed that stagnant atmospheric conditions led to SAPE in New Delhi by allowing pollution to accumulate and persist in the near-surface environment. As a result new particle formation was suppressed due to very high pre-existing aerosol concentrationsAbstract: In recent years, South Asia is experiencing severely degraded air quality, with particulate matter less than 2.5 μm (PM2.5 ) reaching unprecedented high levels. Here, we investigate a severe air pollution episode (SAPE) witnessed in New Delhi during 1–7 November 2016. This was a very unusual air pollution episode wherein air quality index exceeded >500 and was persistent for about a week encapsulating the entire Indo-Gangetic Plain (IGP). We demonstrate that a stagnant weather condition was the dominant cause of the SAPE. Mean concentration of PM2.5 in New Delhi before, during, and after the SAPE were 142 μg/m 3, 563 μg/m 3, and 240 μg/m 3, respectively. Satellite-based aerosol optical depth (AOD), ultraviolet-aerosol index (UV-AI) and surface carbon monoxide (CO) concentrations also showed significant enhancements over large locale spatially by about 50–70% during the SAPE. A large and simultaneous increase in UV-AI and CO downwind of a large number of fire hotspots (Punjab and Haryana) is a clear indication of biomass burning aerosols. Analysis of absorption Ångström exponent further substantiates this finding, showing a large fraction of light absorbing carbonaceous-type aerosols. Radiosonde observations clearly showed that stagnant atmospheric conditions led to SAPE in New Delhi by allowing pollution to accumulate and persist in the near-surface environment. As a result new particle formation was suppressed due to very high pre-existing aerosol concentrations during the SAPE. The heating rate induced by light absorbing aerosols into an atmospheric layer during SAPE was also very high (3.1 ± 0.7 K/day). These findings will help in understanding air quality and climate effects, as well as in formulating policies to mitigate these complex pollution episodes in an anthropogenic future. Highlights: Satellite products offer entrenched approach to monitor near-surface air quality. New Delhi witnessed the worst severe air pollution episode during November 2016. Air stagnation played a vital role in the occurrence of severe air pollution episode. … (more)
- Is Part Of:
- Atmospheric environment. Volume 222(2020)
- Journal:
- Atmospheric environment
- Issue:
- Volume 222(2020)
- Issue Display:
- Volume 222, Issue 2020 (2020)
- Year:
- 2020
- Volume:
- 222
- Issue:
- 2020
- Issue Sort Value:
- 2020-0222-2020-0000
- Page Start:
- Page End:
- Publication Date:
- 2020-02-01
- Subjects:
- Biomass burning -- Severe air pollution episode -- Particulate matter -- Indo-Gangetic plain
Air -- Pollution -- Periodicals
Air -- Pollution -- Meteorological aspects -- Periodicals
551.51 - Journal URLs:
- http://www.sciencedirect.com/web-editions/journal/13522310 ↗
http://www.elsevier.com/journals ↗ - DOI:
- 10.1016/j.atmosenv.2019.117125 ↗
- Languages:
- English
- ISSNs:
- 1352-2310
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
- Physical Locations:
- British Library DSC - 1767.120000
British Library DSC - BLDSS-3PM
British Library HMNTS - ELD Digital store - Ingest File:
- 12815.xml