Meteorology Factors Change In Beijing-Tianjin-Hebei And Relationship Between Meteorology Factors Change And Ambient Air Quality

Beijing Tianjin Hebei region(Jing-Jin-Ji)is China's"capital economic circle",which is located in the temperate zone of the northern hemisphere and adjacent to the Bohai Sea in the East.It is an area with obvious climate change in China;In recent years,the rapid development of this area has affected the local ambient air,so it has attracted more and more attention.It is of certain significance to study the changing trend of meteorological factors and its impact on ambient air quality in Jing-Jin-Ji region,which can provide reference materials for predicting the climate change trend and improving the air quality in this region.Firstly,this paper selects and collects the ground meteorological observation data such as average temperature,minimum temperature,maximum temperature,precipitation,average wind speed and maximum wind speed of four main meteorological stations in Jing-Jin-Ji(Beijing,Tianjin,Shijiazhuang and Chengde)in recent 60 years,using Mann-Kendall test method,Sen's slope estimator test,wavelet analysis M-k mutation point analysis and R/S analysis are used to analyze the change trend,characteristics and future development trend of meteorological factors in this area in recent 60 years.Secondly,the air quality data of four major cities in Jing-Jin-Ji region(Beijing,Tianjin,Shijiazhuang and Chengde)from 2014 to 2019 are collected.The correlation analysis method is used to analyze the relationship between various meteorological factors and the concentration of air pollutants(PM_2.5,PM₁₀,CO,NO₂,SO₂,O₃)and ambient air quality index(AQI)in Jing-Jin-Ji from 2014 to 2019.The main conclusions are as follows:(1)the average temperature and the average highest temperature of the four major meteorological stations in the Jing-Jin-Ji region show a significant increase in the past60 years,and the annual precipitation shows a downward trend.There are differences in the changes of average minimum temperature,average wind speed and average maximum wind speed.The average minimum temperature of Tianjin,Shijiazhuang and Beijing meteorological stations have a significant upward trend,and the average wind speed and average maximum wind speed show a downward trend;the average lowest temperature of Chengde meteorological station shows a downward trend,and the average wind speed and average maximum wind speed are rising.(2)M-K mutation point analysis shows that the annual average temperature,average lowest temperature,average temperature and average highest temperature of the four major weather stations occurred between the 1980s and early 1990s.The annual precipitation and annual average wind speed of Tianjin,Chengde and Shijiazhuang meteorological stations does not change abruptly,while the annual precipitation and annual average wind speed of Beijing meteorological stations changed abruptly after the beginning of the 21st century and 2017 respectively.(3)The annual average temperature,average minimum temperature,average maximum temperature,annual precipitation,average wind speed and average maximum wind speed of the four main meteorological stations have periodic fluctuations of 19?25a and 34?40a,with significant periodic changes.(4)The phenomenon of Hurst appeared in the time series of meteorological factors studied by the four meteorological stations,which has positive persistence,indicating that the future change trend of meteorological factors is consistent with the historical trend.(5)Precipitation,average temperature,average minimum temperature,average highest temperature,average wind speed and average maximum wind speed are negatively associated with PM_2.5,PM₁₀,CO,NO₂,and SO₂ concentrations,and positively associated with O₃.The meteorological factors are negatively correlated with the AQI index,and average wind speed and average maximum wind speed show significant negative correlations with the AQI.