Intensive agricultural activities in the North China Plain (NCP) lead to substantial emissions of nitrogen oxides (NOx) from soil, while the role of this source on local severe ozone pollution is unknown. This study uses a mechanistic parameterization of soil NOx emissions combined with two atmospheric chemistry models (GEOS-Chem and WRF-Chem) to investigate the impact of soil NOx on ozone pollution. The presence of soil NOx emissions significantly reduces the sensitivity of ozone to anthropogenic emissions, decreasing ozone air quality improvements achievable by controlling anthropogenic emissions by 30%. This effect creates an emission control penalty, requiring larger emission reductions to meet ozone regulation targets. As NOx emissions from fuel combustion are controlled, the soil emission penalty becomes increasingly important and must be considered in emission control strategies.

Xiao Lu, Xingpei Ye, Mi Zhou, Yuanhong Zhao, Hongjian Weng, Hao Kong, Ke Li, Meng Gao, Bo Zheng, Jintai Lin, Feng Zhou, Qiang Zhang, Dianming Wu, Lin Zhang, Yuanhang Zhang