An unexpected large continental source of reactive bromine and chlorine with significant impact on wintertime air quality [post]

Xiang Peng, Weihao Wang, Men Xia, Hui Chen, Akkihebbal Ramaiah Ravishankara, Qinyi Li, Alfonso Saiz-Lopez, Pengfei Liu, Fei Zhang, Chenglong Zhang, Likun Xue, Xinfeng Wang (+5 others)
2020 unpublished
Halogen atoms affect the budget of ozone and the fate of pollutants such as hydrocarbons and mercury. Yet their sources and significances in polluted continental regions are poorly understood. Here we report the observation of unprecedented levels (averaging at 60 parts per trillion) of bromine chloride (BrCl) at a mid-latitude site in North China during winter. Widespread coal burning in rural households and a photo-assisted process were the primary source of BrCl and other bromine gases. BrCl
more » ... contributed about 55% of both bromine and chlorine atoms. The halogen atoms increased the abundance of 'conventional' tropospheric oxidants (OH, HO 2 and RO 2 ) by 26%-73%, and enhanced oxidation of hydrocarbon by nearly a factor of two and the net ozone production by 55%. Our study reveals the significant role of reactive halogen in winter atmospheric chemistry and the deterioration of air quality in continental regions where uncontrolled coal combustion is prevalent.
doi:10.1002/essoar.10504290.2 fatcat:rcvfuoiwubhfllenlbf72a3p7e