Ozone pollution in the North China Plain spreading into the late-winter haze season.
Ozone pollution in the North China Plain spreading into the late-winter haze season.
复制标题
华北平原臭氧污染蔓延至冬末雾霾季节
DOI：
10.1073/pnas.2015797118
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发表时间：
2021-03-09
影响因子：
11.1
通讯作者：
Kuk SK
中科院分区：
文献类型：
--
作者：
Li K;Jacob DJ;Liao H;Qiu Y;Shen L;Zhai S;Bates KH;Sulprizio MP;Song S;Lu X;Zhang Q;Zheng B;Zhang Y;Zhang J;Lee HC;Kuk SK
华北平原夏季臭氧污染严重，而冬季雾霾（颗粒物）污染事件期间臭氧含量一直很低。在此，我们显示，二零二零年一月COVID-19封城后氮氧化物（NOx）排放量突然减少，导致冬季雾霾事件期间臭氧快速产生，接近空气质量标准。这种快速的臭氧产生是由来自挥发性有机化合物（VOC）的高排放的甲醛驱动的。COVID-19疫情凸显了2013年至2019年中国冬春季臭氧污染迅速增加的总体趋势，因为氮氧化物排放量减少。挥发性有机化合物排放控制将缓解臭氧污染向冬春季的蔓延，有利于公共卫生、作物生产和颗粒物污染。地表臭氧是华北平原严重的空气污染问题，华北平原是3亿人口的家园。臭氧浓度在夏季最高，这是由快速光化学产生的氢氧化物自由基（HOx）驱动的，这种自由基可以克服燃料燃烧产生的氮氧化物（NOx）的高排放所引起的自由基滴定。臭氧在冬季雾霾（颗粒物）污染事件期间非常低。然而，二零二零年一月COVID-19封城后氮氧化物排放量突然减少，显示冬季烟霾期间转为快速产生臭氧，最高每日8小时平均（MDA 8）臭氧浓度为十亿分之六十至七十。我们用GEOS-Chem模型再现了这种开关，其中臭氧的快速产生是由甲醛光解产生的HOx自由基驱动的，克服了减少NOx排放的自由基滴定。甲醛是由活性挥发性有机物（VOCs）氧化产生的，在华北平原具有很高的排放量。封锁后1月至2月向臭氧产生机制的显着转变表明，2013年至2019年，华北平原冬春臭氧增加，高臭氧与冬季雾霾事件的关联性增强，这是一个更普遍的趋势，因为污染控制工作的目标是氮氧化物排放量（减少30%），而挥发性有机化合物排放量保持不变。减少挥发性有机化合物的排放将避免严重的臭氧污染事件进一步蔓延到冬春季节。
Significance The North China Plain experiences severe summer ozone pollution, but ozone during winter haze (particulate) pollution events has been very low. Here, we show that the abrupt decrease in nitrogen oxide (NOx) emissions following the COVID-19 lockdown in January 2020 drove fast ozone production during winter haze events to levels approaching the air quality standard. This fast ozone production was driven by formaldehyde originating from high emissions of volatile organic compounds (VOCs). The COVID-19 experience highlights a general 2013 to 2019 trend of rapidly increasing ozone pollution in winter–spring in China as NOx emissions have decreased. VOC emission controls would mitigate the spreading of ozone pollution into winter–spring with benefits for public health, crop production, and particulate pollution. Surface ozone is a severe air pollution problem in the North China Plain, which is home to 300 million people. Ozone concentrations are highest in summer, driven by fast photochemical production of hydrogen oxide radicals (HOx) that can overcome the radical titration caused by high emissions of nitrogen oxides (NOx) from fuel combustion. Ozone has been very low during winter haze (particulate) pollution episodes. However, the abrupt decrease of NOx emissions following the COVID-19 lockdown in January 2020 reveals a switch to fast ozone production during winter haze episodes with maximum daily 8-h average (MDA8) ozone concentrations of 60 to 70 parts per billion. We reproduce this switch with the GEOS-Chem model, where the fast production of ozone is driven by HOx radicals from photolysis of formaldehyde, overcoming radical titration from the decreased NOx emissions. Formaldehyde is produced by oxidation of reactive volatile organic compounds (VOCs), which have very high emissions in the North China Plain. This remarkable switch to an ozone-producing regime in January–February following the lockdown illustrates a more general tendency from 2013 to 2019 of increasing winter–spring ozone in the North China Plain and increasing association of high ozone with winter haze events, as pollution control efforts have targeted NOx emissions (30% decrease) while VOC emissions have remained constant. Decreasing VOC emissions would avoid further spreading of severe ozone pollution events into the winter–spring season.
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影响因子：
4.4
作者：
Jaegle, L.;Shah, V.;Weber, R. J.
通讯作者：
Weber, R. J.
影响因子：
13.6
作者：
Gaudel, Audrey;Cooper, Owen R.;Granier, Claire
通讯作者：
Granier, Claire
影响因子：
64.8
作者：
Edwards, Peter M.;Brown, Steven S.;Zamora, Robert
通讯作者：
Zamora, Robert
DOI：
10.1073/pnas.1900125116
发表时间：
2019-04-30
影响因子：
11.1
作者：
An, Zhisheng;Huang, Ru-Jin;Ji, Yuemeng
通讯作者：
Ji, Yuemeng
影响因子：
4.9
作者：
Gelaro, Ronald;McCarty, Will;Zhao, Bin
通讯作者：
Zhao, Bin