The Spatial And Temporal Distribution Of Ozone Concentration In Wuhan City Was Analyzed Based On GTWR Model

Ozone（O₃）is an oxidizing gas commonly existing in the atmosphere.A small amount of near-ground ozone originates from natural formation,and most of it is formed by primary pollutants such as nitrogen oxides and volatile organic compounds in complex photochemical reactions.According to the 2016-2020 atmospheric environment quality report of Wuhan,ozone has become one of the primary air pollutants,and the problem of ozone pollution has increasingly become the focus of attention.Wuhan covers a total area of about 8,569 square kilometers,and there are 22atmospheric environmental monitoring stations,with an average of 389.5 square kilometers for one environmental monitoring station.Moreover,most of the monitoring stations are concentrated in the main urban area,while the density in the outer urban area is small and unevenly distributed,which cannot reflect the spatial heterogeneity of ozone concentration distribution in Wuhan.To fully explore wuhan ozone space-time distribution characteristics,this paper to achieve encryption effect,the net was established based on Arc GIS control points,the density of 0.03°×0.03°,using GTWR model simulation projections for fishing site of ozone,and analysis of time and space distribution of ozone in wuhan city and interannual variability,fully explore wuhan ozone time-space distribution characteristics;The GTWR model was used to analyze the ozone concentration data of 2016-2020 environmental monitoring points in Wuhan City,with pollutants(O₃,SO₂,NO₂,CO,PM₁₀,PM_2.5),meteorological factors（including:total cloud cover,zonal wind speed,meridional wind speed,2-meter air temperature,2-meter dew point temperature,relative humidity,horizontal wind speed）as input parameters,and the dominant factors affecting ozone concentration were obtained.The results showed that 2016--2020 time variation of ozone concentration in Wuhan obvious interannual variability of ozone concentration in Wuhan outstanding,fell after the first rise in annual average;ozone concentration changes with the seasons after the overall performance from spring to winter increased and then decreased,The ozone concentration is highest in summer,lowest in winter,and middle in spring and autumn;Ozone concentration on the mean lower after January-December first increases,the vast majority are irregular"M"for bimodal type change,the minority is unimodal type inverted"V"shaped,a handful of multiple peak type change.Ozone time change is mainly related to meteorological factors,ozone concentration change with temperature,the summer temperatures high light chemical reaction to generate ozone,whereas the winter has inhibitory effect on ozone generated at low temperature,ozone peak was mainly affected by the rainy season,the rainy season is concentrated in the summer in July and August are characterized by bimodal type,the rainy season in advance or delay of unimodal type,the rainy season dispersion type appears multi-peak irregular change.There is spatial heterogeneity in the distribution of ozone concentration in Wuhan.The high concentration area is mainly distributed in the main urban area and the far urban area near the main urban area,and the low ozone concentration is distributed in the edge of the far urban area.The overall spatial distribution shows that the ozone concentration is distributed in the order of medium,high and low from the center to the edge of the far urban area.Compared with the spatial difference of ozone data of environmental monitoring stations in Wuhan,it is shown that the concentration in the far urban area is higher than that in the main urban area.The reason for the inconsistency is that the spatial distribution of monitoring points is uneven,which is not enough to reflect the details of the spatial distribution of ozone.The reason for the spatial heterogeneity is that the factories and enterprises in Wuhan are mostly distributed in the far urban areas on the edge of the main urban area,which is an important emission source of ozone precursor pollutants VOCs.In addition,the main urban areas are densely populated,the vehicle flow is large,and there are many vehicle exhaust emissions,including ozone precursor pollutants,and the urban heat island effect pollutants are not easy to spread in summer.Wuhan ozone concentration influence factors of meteorological factors,air temperature,relative humidity and total cloud cover the correlation is stronger,were positively correlated,negative correlation,negative correlation relationship,small wind speed correlation,and meridional winds were positively correlated,and negatively correlated with zonal wind;SO₂and PM₁₀ have no correlation with ozone,but NO₂,CO and PM_2.5 have negative correlation with ozone.Higher temperatures usually exceeding ozone,cloudiness and low humidity,i.e.ozone pollution prone to high temperature and low in sunny day.By analyzing the space-time distribution of ozone in Wuhan city,can provide theoretical support for government departments to ozone pollution control and decision-making reference.