2015—2017年中国近地面O3污染状况与影响因素分析

Situation and Influencing Factors of Ground-level Ozone Pollution in China from 2015 to 2017

利用2015-2017年环保部发布的近地面臭氧(O3)和其他3种污染物[粒径小于2. 5μm的颗粒物(PM2.5)、一氧化碳(CO)、二氧化氮(NO2)]小时浓度数据和美国国家气候资料中心收集的气象要素监测数据,分析了中国近地面O3污染状况,并用逐步回归方法分析了影响O3重污染区域夏季近地面O3浓度的因素。结果表明,2015-2017年我国O3日最大8 h滑动平均浓度(O3MDA8)年平均值分别为83.02±16. 79,87. 05±14. 32和94. 70±13. 89μg·m-3。O3MDA8浓度逐年增长(增长率14. 07%),其中冬季增长最快(增长率范围14. 67%~34. 32%),夏季增长最慢(增长率范围2. 32%~14. 16%)。京津冀、长三角、山东半岛、川渝和中原地区近地面O3污染较重,影响这5个区域近地面O3浓度的主要因素为温度、相对湿度和PM2.5,除此之外京津冀和川渝地区的近地面O3浓度受NO2影响明显,中原地区的近地面O3浓度受CO影响明显。

Based on hourly concentration of ozone( O3) and other three pollutants( fine particles with a diameter of2. 5 μm or less( PM2.5),carbon monoxide( CO),nitrogen dioxide( NO2)) released by the Chinese Ministry of Environmental Protection from 2015 to 2017,and the meteorological data archived by National Climatic Data Center,the situation of ground-level O3 pollution in China was analyzed. The factors influencing summer ground-level O3 in heavily polluted areas was evaluated by stepwise regression. The results showed that the annual mean of daily maximum 8-hour average ozone concentration( O3 MDA8) in China during the years of 2015-2017 were 83. 02±16. 79,87. 05±14. 32 and 94. 70±13. 89 μg·m-3 respectively. The exceeding rates of O3 MDA8 were 6. 61%±6. 47%,6. 74%±6. 25% and 8. 95%±7. 61% respectively. The ground-level O3 pollution in China is very heavy and the situation is becoming worse. The concentration of O3 MDA8 increased( growth rate was 14. 07%) from2015 to 2017,with the fastest increase in winter( growth rate ranged from 14. 67% to 34. 32%) and the slowest increase in summer( growth rate ranged from 2. 32% to 14. 16%),which could be attributed to the growing concentration of O3 in background. Summer was the most polluted season of ground-level O3,with exceeding rate of 14.93% ±16. 31%,while the exceeding rate were 8. 92%±9. 27% in spring,5. 49%±6. 80% in autumn and 0. 28%±1. 27% in winter. The ground-level O3 pollution in the five most developed areas of China,i. e. Jinjingji,Yangtze River delta,Shangdong Peninsula,Chuanyu and Central China regions,was heavier than other areas. Temperature,relative humidity and PM2.5 were the main factors affecting O3 MDA8 in these five heavily polluted areas. In addition,the O3 MDA8 in Jinjingji and Chuanyu were more affected by NO2 compared to the other three heavily polluted areas,which could be explained by the large number of vehicles in these two areas. The O3 MDA8 in Central China regions were more affected by CO than in other areas,which could be attributed to the large usage of coal in this area. This study is helpful to deeply understand the current situation of O3 pollution in China,and provides a reference for policy maker to formulate targeted prevention and control measures.