研究报告
杨溟鋆,王咏薇,张丹,幸礼峰.重庆臭氧时空分布特征及其污染成因的初步分析[J].环境科学学报,2021,41(12):5026-5037
重庆臭氧时空分布特征及其污染成因的初步分析
- A preliminary analysis of the characteristics of ozone and the cause of its pollution in Chongqing
- 基金项目：国家重点研发计划（No.2017YFC0210102）
- 作者
- 单位
- 杨溟鋆
- 1. 南京信息工程大学大气物理学院, 南京 210044;2. 南京信息工程大学大气环境中心, 南京 210044
- 王咏薇
- 1. 南京信息工程大学大气物理学院, 南京 210044;2. 南京信息工程大学大气环境中心, 南京 210044
- 张丹
- 3. 重庆市生态环境科学研究院, 城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147
- 幸礼峰
- 1. 南京信息工程大学大气物理学院, 南京 210044
- 摘要：近年,臭氧(O3)正逐渐取代PM2.5成为中国首要大气污染物.因此,研究O3的时空分布特征及污染成因对于空气污染治理与管控具有重要价值.重庆复杂的地形造成该地区O3的污染成因具有很大的不确定性.采用2013—2020年重庆市主城区环境监测站O3、PM2.5、NO2逐小时监测数据和国家气象站观测资料,分析了O3的时空分布特征,并探究其与复杂地形、前体物、气象要素及PM2.5的关系.结果表明:①2013—2020年臭氧日最大8 h平均浓度的第90百分位值年际变化总体呈现先减后增的趋势.发生臭氧污染月份数量增加,臭氧污染开始月份从6月提前到4月.②2019年重庆臭氧中度和重度(中重度)污染天数最多,为6 d.2013—2015年中重度污染频率由1.09%减少至0.27%,到2019年增加至1.64%,2020年降至0.81%.③重庆中重度污染期间,O3的空间分布受山谷风环流与城市热岛效应的共同影响.白天城区站点O3浓度高于山区站点O3浓度,夜间山区站点O3浓度高于城区站点O3浓度.④城区站点的O3与NO2浓度呈现显著负相关,山区站点O3与NO2浓度的相关系数为负值,但相关性不显著.⑤重庆大部分O3中重度污染由局地污染主导,在非高温或者高湿的情况下同样可能发生臭氧中重度污染.臭氧中重度污染发生时,风向多为西-北风.O3浓度与气温和风速呈显著正相关,与相对湿度呈负相关.⑥重庆O3-PM2.5相关性城区与山区表现不一致,城区南坪站O3-PM2.5在暖季呈正相关关系,冷季相关性有正有负,山区缙云山站O3-PM2.5在暖季和冷季都呈正相关关系.
- Abstract：O3 is replacing PM2.5 as the primary pollutant in China in recent years. Therefore, studying the characteristics of O3 and the causes of pollution are of great value to the government and control of air pollution. The complicated topography of Chongqing causes great uncertainty in the cause of O3 pollution in this area. In this paper, the hourly monitoring data of O3, PM2.5 and NO2 from Air Quality Monitoring Stations and the meteorological data from the National Reference Climate Stations from 2013 to 2020 are used to analyze the temporal and spatial distribution of O3 and its connection with topography, precursors, meteorological variables, and PM2.5. The results show that: ①the 90th percentile of the daily maximum 8-hour average O3 concentration shows a trend of decreasing first and then increasing from 2013 to 2020. The number of months that O3 pollution occurs increase, and the start month advances from June to April. ②The moderate and severe O3 pollution occurs mostly in 2019 (6 days). The frequency of moderate and severe pollution decreases from 1.09% to 0.27% from 2013 to 2015, and increases to 1.64% in 2019, while decreases to 0.81% in 2020. ③During the period of moderate and severe O3 pollution in Chongqing, the spatial distribution of O3 is affected by the valley breeze and the urban heat island. During the day, the O3 concentration in the urban sites is higher than that in the mountain sites, while the conditions reverse at night. ④The concentration of O3 and NO2 in urban sites is obviously inversely correlated, but not in the mountain site. ⑤Most of the moderate and severe O3 pollution occurs in Chongqing is dominated by local pollution. Severe ozone pollution also occurs under conditions of non-high temperature or high humidity. When moderate and severe O3 pollution occurs, the wind direction is mostly northwest. O3 concentration is significantly positively correlated with air temperature and wind speed, negatively correlated with relative humidity. ⑥Correlation between O3 and PM2.5 is different in urban areas and mountainous areas. The correlation in NP Station in the urban area is positive in the warm season, and positive or negative in the cold season; the correlation in JYS Station in the mountainous area is positive in warm and cold seasons.
- Key words：mountain city Chongqing O3 pollution causes of moderate to severe pollution meteorological conditions PM2.5 correlation
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