Objective evaluation of stubble emission of North India and quantifying its impact on air quality of Delhi.

Crop residue burning during post monsoon season in the neighboring provinces leads to frequent episodes of extreme pollution events, associated with premature morbidity and mortality. A synergistic use of multiple satellite measurements in conjunction with actual field incidences data at the ground led us to develop the realistic high-resolution emission inventory of the hazardous pollutant PM2.5 due to stubble burning. We quantify the share of biomass burning in deteriorating Delhi's air quality during 2018 using the SAFAR chemical transport model that has been validated with dense observational network of Delhi. The impact of biomass burning on Delhi's PM2.5 is found to vary on day-to day basis (peaking at 58%) as it is highly dependent on transportation pathway of air mass, controlled by meteorological parameters from source to target region. Comprehending the multi-scale nature of such events is crucial to plan air quality improvement strategies.