2018—2022年湖北省臭氧污染特征及气象条件影响分析

Characteristics of ozone pollution and its relationship with meteorological factors in Hubei Province from 2018 to 2022

基于2018—2022年湖北省17个城市68个站点的逐小时O_(3)观测资料,分析了O_(3)长期变化特征和空间分布特征.在此基础上,结合同期气象资料识别了湖北省臭氧不利气象区间,分析了气象条件变化对臭氧浓度的影响.结果表明:(1)长期趋势上,湖北省O_(3)-8 h年均浓度呈“N”型分布,2019年O_(3)-8 h年均浓度最高,为158μg·m^(-3),其次为2022年,为154μg·m^(-3).2022年臭氧污染天占比为48.3%,首次超过PM_(2.5)污染天占比45.9%.月变化上,臭氧呈“M”型分布,4—10月臭氧浓度相对较高.日变化上,不同季节下均呈“单峰”分布,一般15:00—16:00达到峰值.(2)空间分布上,湖北省呈现“东部>中部>西部”分布特征,且2022年中部地区臭氧污染加重.(3)当日均气温[28℃,32℃)、日最高气温[30℃,35℃)、日均相对湿度[50%,60%)、日最低相对湿度[30%,40%)、日均风速[2 m·s^(-1),3 m·s^(-1))、风向为偏南风时,湖北省易发生臭氧污染.黄石、黄冈、天门、潜江等城市易受到武汉污染传输影响,应加强城际间的联防联控.(4)2022年处于臭氧不利气象区间的天数占比为近5年最高,说明不利气象条件是2022年臭氧浓度显著上升的重要原因.

Based on the hourly observation data of O_(3) from 68 stations in 17 cities in Hubei Province from 2018 to 2022,this paper analyzes the longterm trend and spatial distribution characteristics of O_(3).The unfavorable meteorological range for ozone was identified and the influence of meteorological conditions on ozone concentration was analyzed by combining meteorological data in the same period.The results show that:①In the long-term trend,the annual average concentration of O_(3)-8 h in Hubei Province shows an"N"type distribution.The highest annual average concentration of O_(3)-8 h was in 2019,reaching 158μg·m^(-3),followed by 2022,reaching 154μg·m^(-3).In 2022,the proportion of ozone pollution days exceeded the proportion of PM_(2.5) pollution days for the first time,reaching 48.3%and 45.9%respectively.In terms of monthly variations,O_(3)-8 h concentration shows an"M"type distribution,and the O_(3)-8 h concentration is relatively high from April to October.In terms of daily variations,it shows a"single peak"distribution in different seasons,generally reaching a peak at 15:00—16:00.②In terms of spatial distribution,Hubei Province shows a distribution characteristic of higher ozone concentration in the east than in the middle,and higher in the middle than in the west.In 2022,ozone pollution in the central region worsened.③When the daily average temperature is[28℃,32℃),the daily maximum temperature is[30℃,35℃),the daily relative humidity is[50%,60%),the daily minimum relative humidity is[30%,40%),the daily average wind speed is[2 m·s^(-1),3 m·s^(-1)),and the wind direction is southeast,ozone pollution is prone to occur in Hubei Province.Citys such as Huangshi,Huanggang,Tianmen,Qianjiang,etc.,are easily affected by pollution transmission from Wuhan,and should strengthen inter-city joint prevention and control.④The proportion of days in the unfavorable meteorological range for ozone in 2022 was the highest in the past five years,indicating that unfavorable meteorological conditions were an important reason for the significant increase in ozone concentration in 2022.