Anthropogenic chlorine emission is an important source of Cl radicals, which plays an important role in the oxidative chemistry of the troposphere. However, its seasonal impacts on surface ozone levels in China have yet been comprehensively explored. In this study, Yingying Hong et. al., conducted numerical simulations for January, April, July and October 2015 by using the Community Multiscale Air Quality (CMAQ) modeling system with updated heterogeneous reactions of nitrogen oxides with particulate chlorine and updated Anthropogenic Chlorine Emission Inventory for China (ACEIC).

The impact of ACEIC was the most significant in January and the least in July due to the high emissions of NOx and VOCs and adverse meteorological conditions in winter. It indicated that although the ozone concentration was low, the anthropogenic chlorine emission significantly contributed to the atmospheric oxidation capacity and increase ozone concentrations in winter.