Impact of weather and emission changes on NO2 concentrations in China during 2014-2019

Yang Shen; Fei Jiang; Shuzhuang Feng; Yanhua Zheng; Zhe Cai; Xiaopu Lyu

doi:10.1016/j.envpol.2020.116163

Impact of weather and emission changes on NO₂ concentrations in China during 2014-2019

Environ Pollut. 2021 Jan 15:269:116163. doi: 10.1016/j.envpol.2020.116163. Epub 2020 Nov 27.

Authors

Yang Shen¹, Fei Jiang², Shuzhuang Feng¹, Yanhua Zheng¹, Zhe Cai³, Xiaopu Lyu⁴

Affiliations

¹ Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing, 210023, China.
² Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing, 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, 210023, China. Electronic address: jiangf@nju.edu.cn.
³ Nanjing Climblue Technology Co., LTD, Nanjing, Jiangsu, 211135, China.
⁴ Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong.

PMID: 33280908
DOI: 10.1016/j.envpol.2020.116163

Abstract

Nitrogen dioxide (NO₂) is one of the most important air pollutants that highly affect the formation of secondary fine particles and tropospheric ozone. In this study based on hourly NO₂ observations from June 2014 to May 2019 and a regional air quality model (WRF-CMAQ), we comprehensively analyzed the spatiotemporal variations of NO₂ concentrations throughout China and in 12 urban agglomerations (UAs) and quantitatively showed the anthropogenic and meteorological factors controlling the interannual variations (IAVs). The ground observations and tropospheric columns show that high NO₂ concentrations are predominantly concentrated in UAs such as Beijing-Tianjin-Hebei (BTH), the Shandong Peninsula (SP), the Central Plain (CP), Central Shaanxi (CS), and the Yangtze River Delta (YRD). For different UAs, the NO₂ IAVs are different. The NO₂ increased first and then decreased in 2016 or 2017 in BTH, YRD, CS, and Cheng-Yu, and decreased from 2014 to 2019 in Harbin-Changchun, CP, SP, Northern Slope of Tianshan Mountain, and Beibu-Gulf, while increased slightly in the Pearl River Delta (PRD) and Hohhot-Baotou-Erdos-Yulin (HBEY). The NO₂ IAVs were primarily dominated by emission changes. The net wintertime decreases of NO₂ in BTH, Yangtze River Middle-Reach, and PRD were mostly contributed by emission reductions from 2014 to 2018, and the significant increase in the wintertime in HBEY was also dominated by emission changes (93%). Weather conditions also have an important effect on the NO₂ IAVS. In BTH and HBEY, the increases of NO₂ in winter of 2016 are mainly attributed to the unfavorable weather conditions and for the significant decreases in the winter of 2017, the favorable weather conditions also play a very important role. This study provides a basic understanding on the current situation of NO₂ pollution and are helpful for policymakers as well as those interested in the study of tropospheric ozone changes in China and downwind areas.

Keywords: NO(2); Quantitative impacts; Spatiotemporal pattern; Urban agglomeration; WRF−CMAQ.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
Beijing
China
Environmental Monitoring
Nitrogen Dioxide / analysis
Particulate Matter / analysis
Seasons
Weather

Substances

Air Pollutants
Particulate Matter
Nitrogen Dioxide