Role of meteorological regime in mitigating biomass induced extreme air pollution events

India is an agriculture-based economy; a large fraction of crop residue is being burned directly on fields that are one of the major sources of air pollution. As the autumn edges towards the cooler winter in mega city Delhi, the fear of smog looms, frequently leading to extreme pollution events caused by burn paddy straw under the hostile weather. The Kharif crop stubble burning starts around the first week of October and lasts up to the end of November. We hereby propose that if the burning period is advanced backward by about a month then the severity of its impact in deteriorating the air quality of Delhi would be significantly reduced due to less hostile meteorological regime. The current work is based on 2018 and generalization of current findings would require a much more comprehensive simulation and protocols. In the present work, an interactive high resolution WRF-Chem model forced with newly developed synergized gridded stubble burning emission inventory of PM2.5 for 2018 is used along with normal emissions. Results indicate that emergency episodes significantly reduced from 12 to nil, under proposed scenario that may help minimizing adverse health impacts. Such effort, however, requires a feasibility study and policy level intervention.

Automated summary

This study suggests advancing the burning period of crop residue by a month to reduce its negative impact on air quality in Delhi. The research used a high resolution WRF-Chem model and a newly developed gridded stubble burning emission inventory, with results showing a significant reduction in emergency episodes that may help minimize adverse health impacts.