Aerosol radiative feedback enhances particulate pollution over India: A process understanding. (1st April 2023)

• Record Type: Journal Article
• Authors: Sharma, Arushi; Venkataraman, Chandra; Muduchuru, Kaushik; Singh, Vikas; Kesarkar, Amit; Ghosh, Sudipta; Dey, Sagnik
• Is Part Of: Atmospheric environment. Volume 298(2023)
• Publication Date: 2023-04-01
• Subjects: WRF-Chem -- Air quality simulations -- Meteorology -- Atmospheric chemistry -- Primary and secondary species; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2023.119609
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: In this study, we investigate the role of aerosol direct radiative feedback on regional meteorological changes and subsequent distribution of air pollutant with the focus on particulate matter PM2.5 and ozone (O3 ) over India. WRF-Chem simulations have been applied for Baseline case with both aerosol direct and indirect effects and another simulation including only aerosol indirect effects. The aerosol direct radiative feedback on the meteorology and air quality were investigated by taking the differences between these two simulations. A comprehensive model evaluation showed the model had the capacity to reproduce the observations and well captured the temporal and spatial variation in meteorological and aerosol fields. We found that the reduction in incoming shortwave solar radiation, temperature at 2 m and planetary boundary layer height annually and across all the season due to aerosol radiation interaction (ARI). The concentration of PM2.5 and gaseous precursors like SO2 and NO2 showed enhancements, while O3 concentration mostly showed a reduction. Spatial and annual average PM2.5 concentration was increased by +6%, SO2 concentration was increased by +1.4%, NO2 concentration was increased by +3.4%, and O3 concentration was reduced by −1.4%. Largest regional increases of 40% in particulate pollution induced by ARI occurred over north-western Indian region. The increase in PM2.5 concentration was highly related to stabilisation induced through meteorological variables and increases in primary aerosol concentration. The decrease in O3 concentration was highly related increases in NO2 and SO2 concentration. In the most polluted regions of India, ARI significantly enhance surface-level particulate pollution and related premature mortality, of particular concern considering likely future increasing trends. This study highlights the importance of inclusion and better representations of ARI and for implementing effective mitigation plans. Graphical abstract: Image 1 Highlights: Online coupled WRF-Chem simulations was analysed to investigate aerosol direct effect. Direct effects reduced radiation, temperature and PBL height, annually and seasonally. PM2.5 levels increased due to ADE where primary aerosol concentrations were dominant. The effects reduced O3 in most of the regions, due to high levels of NO2 and SO2 . PM2.5 levels due to ADE has implications on estimation of premature mortality.