Zhang Chengxin, Liu Cheng, Hu Qihou, Cai Zhaonan, Su Wenjing, Xia Congzi, Zhu Yizhi, Wang Siwen, Liu Jianguo
1School of Earth and Space Sciences, University of Science and Technology of China, 230026 Hefei, China.
2Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, 230026 Hefei, China.
Light Sci Appl. 2019 Nov 13;8:100. doi: 10.1038/s41377-019-0210-6. eCollection 2019.
Abundances of a range of air pollutants can be inferred from satellite UV-Vis spectroscopy measurements by using the unique absorption signatures of gas species. Here, we implemented several spectral fitting methods to retrieve tropospheric NO, SO, and HCHO from the ozone monitoring instrument (OMI), with radiative simulations providing necessary information on the interactions of scattered solar light within the atmosphere. We analyzed the spatial distribution and temporal trends of satellite-observed air pollutants over eastern China during 2005-2017, especially in heavily polluted regions. We found significant decreasing trends in NO and SO since 2011 over most regions, despite varying temporal features and turning points. In contrast, an overall increasing trend was identified for tropospheric HCHO over these regions in recent years. Furthermore, generalized additive models were implemented to understand the driving forces of air quality trends in China and assess the effectiveness of emission controls. Our results indicated that although meteorological parameters, such as wind, water vapor, solar radiation and temperature, mainly dominated the day-to-day and seasonal fluctuations in air pollutants, anthropogenic emissions played a unique role in the long-term variation in the ambient concentrations of NO, SO, and HCHO in the past 13 years. Generally, recent declines in NO and SO could be attributed to emission reductions due to effective air quality policies, and the opposite trends in HCHO may urge the need to control anthropogenic volatile organic compound (VOC) emissions.
通过利用气体物种独特的吸收特征，可从卫星紫外 - 可见光谱测量中推断出一系列空气污染物的丰度。在此，我们采用了几种光谱拟合方法，从臭氧监测仪（OMI）中反演对流层中的一氧化氮（NO）、二氧化硫（SO）和甲醛（HCHO），辐射模拟提供了大气中散射太阳光相互作用的必要信息。我们分析了2005 - 2017年期间中国东部地区卫星观测到的空气污染物的空间分布和时间趋势，特别是在污染严重的地区。我们发现，自2011年以来，大多数地区的NO和SO呈显著下降趋势，尽管时间特征和转折点各不相同。相比之下，近年来这些地区对流层HCHO总体呈上升趋势。此外，我们还采用了广义相加模型来了解中国空气质量趋势的驱动因素，并评估排放控制的有效性。我们的结果表明，尽管气象参数，如风速、水汽、太阳辐射和温度，主要主导了空气污染物的日常和季节性波动，但在过去13年中，人为排放对环境中NO、SO和HCHO浓度的长期变化起到了独特作用。一般来说，近期NO和SO的下降可归因于有效的空气质量政策导致的排放减少，而HCHO的相反趋势可能促使有必要控制人为挥发性有机化合物（VOC）的排放。
