武汉城市圈O_(3)时空特征及气象因素的影响

Spatio-temporal Distribution Characteristics of O_(3)and Correlation Analysis of Meteorological Factors in Wuhan Metropolitan Area

文章基于2015-2020年武汉城市圈81个国控点和省控点空气自动站的臭氧监测数据,分析了武汉城市圈臭氧浓度的时空分布特征以及与典型气象因子的相关性。结果表明:时间上,2015-2017年武汉城市圈臭氧年均浓度和超标天数逐步下降,至2017年达到低点。2018年开始快速上升,至2019年达到峰值。之后由于新冠疫情的影响,2020年臭氧浓度和超标天数均有所下降。空间上,武汉城市圈臭氧年均浓度整体东部城市高于西部汉江平原城市,并在较高臭氧浓度范围内其空间分布差别不大。武汉城市圈臭氧浓度与湿度(>25%时)、气压、降水量呈负相关关系,与温度呈正相关关系。城市站点臭氧浓度高值大多出现在低风速时期(<4 m/s)。就风向而言,鄂州、黄冈、黄石、潜江、天门、仙桃、孝感站点臭氧的8 h浓度高值大多出现在南风,特别是东南风。咸宁站点臭氧高值时风向分布较为分散,而武汉市臭氧高值主要出现在西北风和东北风情形。

Based on the ozone monitoring data of 81 national control points and provincial control points in Wuhan from 2015 to 2020,this paper analyzed the spatio-temporal distribution characteristics of ozone concentration in Wuhan metropolitan area and its correlation with typical meteorological factors.The results show that the average annual ozone concentration and the number of days exceeding the standard gradually decreased in Wuhan metropolitan area,and reached the low point in 2017.It began to rise rapidly in 2018 and reached a peak in 2019 from 2015 to 2017.Due to the impact of the COVID-19 pandemic,the ozone concentration and the number of days exceeding the standard decreased in 2020.Spatially,the average annual ozone concentration of the eastern cities in Wuhan metropolitan area was higher than that of the western cities in Hanjiang Plain which showed spatial uniformity in the higher ozone concentration range.Ozone concentration in Wuhan metropolitan area is negatively correlated with humidity(above 25%),atmospheric pressure and precipitation,and positively correlated with temperature.The high ozone concentration of urban stations mostly occurred in the period of low wind speed(less than 4 m/s).In terms of wind direction,the high 8-hour concentration of ozone at Ezhou,Huanggang,Huangshi,Qianjiang,Tianmen,Xiantao and Xiaogan stations mostly occurred with the south wind,especially the southeast wind.The wind direction distribution of high ozone value in Xianning station is relatively scattered,while the high ozone value in Wuhan mainly occurs with the northwest wind and northeast wind.