High efficiency of livestock ammonia emission controls in alleviating particulate nitrate during a severe winter haze episode in northern China

Abstract

Abstract. Although nitrogen oxide ( NOx ) emission controls have been\nimplemented for several years, northern China is still facing high\nparticulate nitrate ( NO 3 - ) pollution during severe haze events\nin winter. In this study, the thermodynamic equilibrium model (ISORROPIA-II)\nand the Weather Research and Forecast model coupled with chemistry (WRF-Chem)\nwere used to study the efficiency of NH3 emission controls on\nalleviating particulate NO 3 - during a severe winter haze\nepisode. We found that particulate- NO 3 - formation is almost NH3 -limited in\nextremely high pollution but HNO3 -limited on the other days. The improvements in manure management of livestock husbandry\ncould reduce 40\u2009% of total NH3 emissions (currently\n100\u2009kt\u2009month −1 ) in northern China in winter. Consequently, particulate\n NO 3 - was reduced by approximately 40\u2009% (on average from 40.8\nto 25.7\u2009 µ g\u2009m −3 ). Our results indicate that reducing livestock\n NH3 emissions would be highly effective in reducing particulate\n NO 3 - during severe winter haze events.