Year-long simulation of gaseous and particulate air pollutants in India

• Published in: Atmospheric environment (1994) 2018-05, Vol.180, p.244-255
• Main Authors: Kota, Sri Harsha, Guo, Hao, Myllyvirta, Lauri, Hu, Jianlin, Sahu, Shovan Kumar, Garaga, Rajyalakshmi, Ying, Qi, Gao, Aifang, Dahiya, Sunil, Wang, Yuan, Zhang, Hongliang
• Format: Article
• Language: English
• Subjects: CMAQ; EDGAR; India; Ozone; Particulate matter; WRF
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2018.03.003

Severe pollution events occur frequently in India but few studies have investigated the characteristics, sources, and control strategies for the whole country. A year-long simulation was carried out in India to provide detailed information of spatial and temporal distribution of gas species and particulate matter (PM). The concentrations of O3, NO2, SO2, CO, as well as PM2.5 and its components in 2015 were predicted using Weather Research Forecasting (WRF) and the Community Multiscale Air Quality (CMAQ) models. Model performance was validated against available observations from ground based national ambient air quality monitoring stations in major cities. Model performance of O3 does not always meet the criteria suggested by the US Environmental Protection Agency (EPA) but that of PM2.5 meets suggested criteria by previous studies. The performance of model was better on days with high O3 and PM2.5 levels. Concentrations of PM2.5, NO2, CO and SO2 were highest in the Indo-Gangetic region, including northern and eastern India. PM2.5 concentrations were higher during winter and lower during monsoon season. Winter nitrate concentrations were 160–230% higher than yearly average. In contrast, the fraction of sulfate in total PM2.5 was maximum in monsoon and least in winter, due to decrease in temperature and solar radiation intensity in winter. Except in southern India, where sulfate was the major component of PM2.5, primary organic aerosol (POA) fraction in PM2.5 was highest in all regions of the country. Fractions of secondary components were higher on bad days than on good days in these cities, indicating the importance of control of precursors for secondary pollutants in India. •WRF-CMAQ system generally reproduces O3 and PM2.5 in India in full year 2015.•Indo-Gangetic region had the highest concentrations of PM2.5, NO2, CO, and SO2.•PM2.5 was highest in winter with increased contribution of nitrate and lowest in monsoon.•POA and sulfate were the major components of PM2.5 except in southern India.•Secondary components were higher on bad days than good days in selected cities. Capsule abstract: Predicted gaseous and particulate air pollutants in India using WRF/CMAQ in 2015 were validated and the variations were analyzed for future source and health analysis.