中国中东部区域本底站气溶胶质量浓度观测空间代表性评估

Analysis of the Spatial Representativeness of Aerosol Mass Concentration Observations at Regional Background Stationsin the center and east of China

中文关键词:  PM_2.5，站点代表性，区域本底站

英文关键词:PM_2.5  spatial representativeness  regional background station

中文摘要:

      采用2010—2021年高分辨率高质量近地表空气污染物数据集PM2.5质量浓度产品对中国中东部地区区域本底站气溶胶质量浓度观测空间代表性进行评估。在使用区域本底站观测数据对数据集检验的基础上，对金沙、临安、上甸子和龙凤山站PM2.5质量浓度观测空间代表性进行评估。将12年数据分为三组（2010—2013, 2014—2017, 2018—2021），采用浓度相似度函数方法，统计代表性面积的平均值、代表性相同的区域面积（即共同面积）和代表性区域的持续性指数，主要结论如下：1.质量浓度相对差异阈值标准取20%时，龙凤山PM2.5日均值的代表性面积平均值（22378 km2）最大，其次是金沙（14490 km2），临安（9841km2）和上甸子（7998 km2）较小。2.共同面积方面：龙凤山站最大（18378 km2），其次是金沙站（11915km2），上甸子站（5687 km2）和临安站（5476km2）较小；持续性方面：金沙和龙凤山代表性区域的持续性高，临安和上甸子持续性一般，四个站点2018—2021年组的代表性面积比2014—2017年组有增大趋势。3.日均值质量浓度相对差异阈值标准为40%及以上时，四个区域本底站的平均（共同）代表性面积可达到中国环保部门规定的空气质量区域本底观测站的代表性面积。4. 采用PM2.5年均值评估的代表性面积、共同面积和持续性均好于采用日均值的评估结果。

英文摘要:

      The spatial representativeness (SR) of aerosol mass concentration observations at regional background stations in the center and east of China was assessed using the PM2.5 product from 2010 to 2021，belonging to a series of high-resolution and high-quality datasets of ground-level air pollutants for China. The quality and reliability of the dataset was evaluated using observations at the background stations. And the SR of PM2.5 at Jinsha (JSA), Lin"an (LAN), Shangdianzi (SDZ) and Longfengshan (LFS) regional background station in the center and east of China were assessed. The Concentration Similarity Function (CSF) was applied to calculate the average, the intersection/common and the persistence index of the SR area at the four stations, dividing the 12 study years into three continuous stages (2010—2013, 2014—2017, 2018—2021). Main conclusions are as follows: 1. With the mass concentration relative difference threshold 20%, LFS station has the largest average SR area 22378 km2, followed by JSA (14490 km2), and LAN (9841 km2) and SDZ (7998 km2) adopting the daily average PM2.5 product. 2. As for the intersection/common SR area, LFS station has the largest area (18378 km2), followed by JSA (11915 km2), with SDZ station (5687 km2) and LAN (5476km2) being relatively small. As for the persistence index of the SR area, JSA and LFS are larger than LAN and SDZ. The SR area during 2018—2021 are larger than that during 2014—2017 at the four regional background stations. 3. If the average (intersection/common ) area satisfy the SR area for the air quality regional background stations specified by the Ministry of Ecology and Environment of China (i.e. with the radius 100 km), mass concentration relative difference threshold of the four stations should set to be ≥40% adopting the daily PM2.5 product. 4. The average, the intersection/common, and the persistence index of the SR area assessed adopting the annual average PM2.5 mass concentrations are all larger or better than those assessed adopting the daily average PM2.5 mass concentrations.