Abstract:Based on the observation data of air quality, meteorological elements, and reanalysis data, the evolution characteristics of air quality in Hubei Province and its adjacent areas from 1 to 30 October 2019, the impacts of meteorological conditions on the air quality during the 7th CISM Military World Games and before and after of this time are analyzed. The concentrations of PM2.5, PM10 in control period Ⅱ (from 17 to 28 October) were lower than the average concentrations in past five years and in other surrounding cities. Control measures were effective in decreasing concentration and restraining ascending velocity. O3 and NO2 were the primary pollutants in control periods (Ⅰ and Ⅱ) (from 13 to 16 October, and 17 to 28 October). Compared with the past five years, the concentration of O3 in Wuhan increased. However, under the background of excessive O3 in other nearby cities, pollution in Wuhan did not reach the polluted level, which indicates the control still took some effects. Actually, the concentration of NO2 was lower than normal years, but higher than that in other cities. Compared with control period Ⅰ, precipitation was less and wind speed was small in control period Ⅱ, thus the meteorological condition was not good for pollutant concentration to decrease. Anticyclonic circulation was dominant from 17 to 21 October, and sunlight and radiation was high with intense photochemical reaction, so concentrations of O3 and NO2 raised obviously. Based on evaluation on meteorological condition index (EMI), EMI was a positive value in 2019 compared with 2013-2017, which indicates that the meteorological conditions in 2019 were not conducive to the reduction of PM2.5, so emission reduction did the most significant contribution to the decreased concentration.