气候变化领域集成服务门户(CCPortal): High atmospheric oxidation capacity drives wintertime nitrate pollution in the eastern Yangtze River Delta of China

CCPortal

DOI	10.5194/acp-22-4355-2022
	High atmospheric oxidation capacity drives wintertime nitrate pollution in the eastern Yangtze River Delta of China
	Zang, Han; Zhao, Yue; Huo, Juntao; Zhao, Qianbiao; Fu, Qingyan; Duan, Yusen; Shao, Jingyuan; Huang, Cheng; An, Jingyu; Xue, Likun; Li, Ziyue; Li, Chenxi; Xiao, Huayun
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	4355
结束页码	4374
卷号	22 期号:7 页码:20
英文摘要	Nitrate aerosol plays an increasingly important role in wintertime haze pollution in China. Despite intensive research on wintertime nitrate chemistry in recent years, quantitative constraints on the formation mechanisms of nitrate aerosol in the Yangtze River Delta (YRD), one of the most developed and densely populated regions in eastern China, remain inadequate. In this study, we identify the major nitrate formation pathways and their key controlling factors during the winter haze pollution period in the eastern YRD using 2-year (2018-2019) field observations and detailed observation-constrained model simulations. We find that the high atmospheric oxidation capacity, coupled with high aerosol liquid water content (ALWC), made both the heterogeneous hydrolysis of dinitrogen pentoxide (N2O5) and the gas-phase OH oxidation of nitrogen dioxide (NO2) important pathways for wintertime nitrate formation in this region, with contribution percentages of 69 % and 29 % in urban areas and 63 % and 35 % in suburban areas during the haze pollution episodes, respectively. We further find that the gas-to-particle partitioning of nitric acid (HNO3) was very efficient so that the rate-determining step in the overall formation process of nitrate aerosol was the oxidation of NOx to HNO3 through both heterogeneous and gas-phase processes. The atmospheric oxidation capacity (i.e., the availability of O-3 and OH radicals) was the key factor controlling the production rate of HNO3 from both processes. During the COVID-19 lockdown (January-February 2020), the enhanced atmospheric oxidation capacity greatly promoted the oxidation of NOx to nitrate and hence weakened the response of nitrate aerosol to the emission reductions in urban areas. Our study sheds light on the detailed formation mechanisms of wintertime nitrate aerosol in the eastern YRD and highlights the demand for the synergetic regulation of atmospheric oxidation capacity and NOx emissions to mitigate wintertime nitrate and haze pollution in eastern China.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000781088200001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273650
作者单位	Shanghai Jiao Tong University; Civil Aviation University of China; Shandong University; Nanjing University
推荐引用方式 GB/T 7714	Zang, Han,Zhao, Yue,Huo, Juntao,et al. High atmospheric oxidation capacity drives wintertime nitrate pollution in the eastern Yangtze River Delta of China[J],2022,22(7):20.
APA	Zang, Han.,Zhao, Yue.,Huo, Juntao.,Zhao, Qianbiao.,Fu, Qingyan.,...&Xiao, Huayun.(2022).High atmospheric oxidation capacity drives wintertime nitrate pollution in the eastern Yangtze River Delta of China.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(7),20.
MLA	Zang, Han,et al."High atmospheric oxidation capacity drives wintertime nitrate pollution in the eastern Yangtze River Delta of China".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.7(2022):20.