Anthropogenic drivers of 2013-2017 trends in summer surface ozone in China
Anthropogenic drivers of 2013-2017 trends in summer surface ozone in China
复制标题
2013-2017年中国夏季地表臭氧变化趋势的人为驱动因素
DOI：
10.1073/pnas.1812168116
复制
发表时间：
2019-01-08
影响因子：
11.1
通讯作者：
Bates, Kelvin H.
中科院分区：
文献类型：
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作者：
Li, Ke;Jacob, Daniel J.;Bates, Kelvin H.
过去5年（2013-2017年），中国各地1,000个类似地点的地面臭氧观测结果显示，夏季污染严重，区域变化趋势。我们解决了气象变化对臭氧趋势的影响，通过使用多元线性回归模型。回归的残差显示，中国东部大城市群的臭氧浓度呈1-3 ppbv a（-1）的增长趋势，我们将其归因于人为排放的变化。相比之下，中国南方部分地区的臭氧减少。据估计，2013-2017年间，中国的人为氮氧化物排放量下降了21%，而挥发性有机化合物（VOCs）排放量变化不大。减少氮氧化物将增加臭氧的挥发性有机化合物限制的条件下，认为在中国城市普遍存在，而减少臭氧的农村氮氧化物限制的条件下。然而，戈达德地球观测系统化学传输模式（GEOS-Chem）的模拟表明，华北平原臭氧趋势的一个更重要的因素是细颗粒物（PM2.5）在2013-2017年期间减少了40%，减缓了过氧氢（HO 2）自由基的气溶胶汇，从而刺激了臭氧的产生。
Observations of surface ozone available from similar to 1,000 sites across China for the past 5 years (2013-2017) show severe summertime pollution and regionally variable trends. We resolve the effect of meteorological variability on the ozone trends by using a multiple linear regression model. The residual of this regression shows increasing ozone trends of 1-3 ppbv a(-1) in megacity clusters of eastern China that we attribute to changes in anthropogenic emissions. By contrast, ozone decreased in some areas of southern China. Anthropogenic NOx emissions in China are estimated to have decreased by 21% during 2013-2017, whereas volatile organic compounds (VOCs) emissions changed little. Decreasing NOx would increase ozone under the VOC-limited conditions thought to prevail in urban China while decreasing ozone under rural NOx-limited conditions. However, simulations with the Goddard Earth Observing System Chemical Transport Model (GEOS-Chem) indicate that a more important factor for ozone trends in the North China Plain is the similar to 40% decrease of fine particulate matter (PM2.5) over the 2013-2017 period, slowing down the aerosol sink of hydroperoxy (HO2) radicals and thus stimulating ozone production.