State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing, China.
State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Sci Total Environ. 2020 May 10;716:136892. doi: 10.1016/j.scitotenv.2020.136892. Epub 2020 Jan 23.
The monthly average PM concentration decreased from 127.15 μg m in December 2016 to 85.54 μg m in December 2017 (approximately 33%) in Central and Eastern China (33°N-41°N, 113°E-118°E). This decrease is attributed to the combined impacts of meteorology and emission sources changes, though the question of which is more important has raised great concerns. Four sensitivity experiments based on the Global-Regional Assimilation and Prediction System coupled with the Chinese Unified Atmospheric Chemistry Environment (GRAPES-CUACE) model, together with comparative analysis of the observed meteorological conditions and emission inventory between 2016 and 2017, are used to evaluate the relative contributions of meteorology and emission to the substantial reductions of PM concentration from December 2016 to December 2017. The results show that the meteorological conditions and emission in December 2017 were both beneficial to the PM decrease in Central and Eastern China. Regarding the entire region, 21.9% of the PM decrease was a result of the favorable meteorological conditions, and 78.1% of the decrease was a result of emission reductions, showing the distinct contributions of emission reductions on the air quality. The relative contributions of meteorology varied from 12.2% to 50.9% to the PM decrease from December 2016 to December 2017, while the emission contributed 49.1% to 87.8%, in different cities depending on geographical location and topography. Meteorology showed the largest contributions to the PM decrease from 2016 to 2017 in Beijing (BJ), which caused the greatest total decrease of PM compared to that of other cities. In addition, in Central and Eastern China, the dominant factors of the decrease of PM were favorable meteorological conditions (accounting for 98.2%) during clear periods and emission reductions (accounting for 72.5-81.2%) during pollution periods.
在中国中部和东部地区（33°N-41°N，113°E-118°E），PM 浓度的月平均值从 2016 年 12 月的 127.15μg/m3 下降到 2017 年 12 月的 85.54μg/m3（约 33%）。这种下降归因于气象和排放源变化的综合影响，尽管哪种因素更为重要引起了极大的关注。利用基于全球-区域同化和预测系统与中国大气综合化学环境耦合的模型（GRAPES-CUACE）进行的四项敏感性试验，并结合 2016 年和 2017 年观测到的气象条件和排放清单的对比分析，评估了气象和排放对 2016 年 12 月至 2017 年 12 月 PM 浓度大幅下降的相对贡献。结果表明，2017 年 12 月的气象条件和排放对中国中部和东部地区的 PM 下降均有利。就整个地区而言，21.9%的 PM 下降是由于气象条件有利，78.1%的下降是由于排放量减少，表明排放量减少对空气质量的明显贡献。气象条件对 2016 年 12 月至 2017 年 12 月 PM 下降的相对贡献从 12.2%到 50.9%不等，而排放对不同城市 PM 下降的贡献从 49.1%到 87.8%不等，具体取决于地理位置和地形。气象条件对北京（BJ）2016 年至 2017 年 PM 下降的贡献最大，导致与其他城市相比，PM 总量下降最大。此外，在中国中部和东部地区，晴朗时期有利的气象条件（占 98.2%）和污染时期的排放减少（占 72.5-81.2%）是 PM 下降的主要因素。
