Rapid aqueous phase SO2 oxidation during winter fog in the Indo-Gangetic Plain

Abstract

This study provides a report on SO2 measurements from IISER Mohali – Ambient Air Quality Station. We use strong point sources of SO2 within the region with known SO2/CO emission ratio for industries 50 km east of our measurement site respectively, to estimate the loss rate of SO2 in wintertime fog in the Indo Gangetic Plain (IGP). The observed loss rate of SO2 is faster than the maximum loss rate through oxidation by H2O2, OH and O3 in the aqueous phase. Models including TMI and Criegee Intermediates may be able to explain the observed loss rates as the pollution plume studied originates from metal industries.