Spatial And Temporal Distribution Of Sulfur Dioxide And Its Influencing Factors In China Based On OMI Data

With the rapid development of industrialization and urbanization in China,a large number of air pollutants have been produced,causing serious harm to the environment and public health.Sulfur dioxide is an important component of trace gases and one of the main pollutants in troposphere.Satellite remote sensing provides an effective means for monitoring and studying air pollutants in a wide range.Therefore,this paper firstly analyzed the spatial and temporal distribution characteristics of atmospheric sulfur dioxide column concentration in China from 2010 to 2019 by using the sulfur dioxide column concentration data retrieved by OMI satellite remote sensing,and extracted the sulfur dioxide column concentration data in various regions of China to analyze the change characteristics of atmospheric sulfur dioxide column concentration in each region.At the same time,the variation coefficient,linear regression method and Hurst index were used to analyze the stability,trend and future trend of the spatial variation of sulfur dioxide concentration in China.Finally,through correlation analysis and combining with temperature,precipitation,vegetation,topography and social and economic data,the factors affecting the temporal and spatial variation of atmospheric sulfur dioxide column concentration in China are discussed.The main conclusions are as follows.(1)The overall spatial distribution of atmospheric sulfur dioxide column concentration in China from 2010 to 2019 is high in the north and low in the south.The high value area is distributed in the north China plain,while the low value area is mainly distributed in south China,most of southwest China and the south of east China.From 2010 to 2014,the sulfur dioxide concentration in the Beijing-Tianjin-Hebei region was on the high side on the whole.From 2015 to 2019,the high-value area centered on the Beijing-Tianjin-Hebei region gradually disappeared,while the low-value area gradually increased.Most of the regions in China are stable in the change trend of atmospheric sulfur dioxide column concentration,and the regions with a large change range are concentrated in the Beijing-Tianjin-Hebei region and the surrounding areas.In spring,the concentration of sulfur dioxide column in China is mainly distributed in grades 1-4;in summer,the concentration of sulfur dioxide column in China is mainly distributed in grades 1-4;in autumn,the concentration of sulfur dioxide column in China is mainly distributed in grades 2-4;and in winter,the concentration of sulfur dioxide column in China is mainly distributed in grades 3-5.In terms of the monthly spatial distribution of sulfur dioxide column concentration,the high-value area of China’s sulfur dioxide column concentration first decreases and then increases,the high-value area in July is the smallest,and the high-value area in January is the largest.(2)From 2010 to 2019,the interannual variation of atmospheric sulfur dioxide column concentration in China shows an overall trend of fluctuation and decline,with a decrease of 0.011 DU/year.The concentration of sulfur dioxide column will reach the lowest value in 2019,which is 0.604 DU.The highest value was 0.744 DU in 2011.The concentration of atmospheric sulfur dioxide column in China varies significantly from season to season.The concentration of sulfur dioxide column is the highest in winter with an average of 0.772 DU,followed by that in autumn with an average of 0.668 DU,followed by that in spring with an average of 0.606 DU,and the lowest in summer with a concentration of 0.531 DU.The monthly sulfur dioxide column in China shows a trend of decreasing first and then increasing.The lowest value basically appears in July of each year,while the highest value appears in January,with a fluctuation range of 0.479DU~0.883 DU.(3)The atmospheric sulfur dioxide column concentration in each region of China is the highest in north China and the lowest in south China.The maximum value of atmospheric sulfur dioxide column concentration in different regions of China varies significantly,while the minimum value varies little.The annual change of sulfur dioxide column concentration in each region is obvious in east China and central China,and shows a significant downward trend from 2012 to 2016.Northeast China and north China always maintain a high concentration value,showing a slow downward trend;The south China region is always in the lowest concentration value,and the northwest and southwest regions remain basically unchanged.In the monthly mean change of sulfur dioxide column concentration in various regions of China,the south China region shows a slow increasing trend,while the other regions show a decreasing trend first and then increasing trend.On the whole,the monthly mean sulfur dioxide column concentration in south China and southwest China is lower than the national level,while the monthly mean sulfur dioxide column concentration in northeast China,north China and east China is higher than the national level.The seasonal variation of sulfur dioxide concentration in all regions showed obvious seasonal characteristics except the south China region.(4)The stability of atmospheric sulfur dioxide column concentration in China presents obvious spatial differences,and the distribution of high fluctuation regions in the Sichuan basin and the north China plain indicates that the stability of this region is poor.The middle and surrounding regions of the two high fluctuation regions show medium fluctuation regions,while most of the other regions are in low fluctuation regions.In China,the significant change of sulfur dioxide column concentration generally shows a decreasing trend,and the significant decrease is mainly distributed in the north China plain,the middle and lower Yangtze river plain,the Guangzhou plain,the Sichuan basin and Liaoning,etc.,with a slight increase in some areas of Xinjiang and basically unchanged in most other areas.The persistence of atmospheric sulfur dioxide concentration in China is mainly characterized by if persistence,and the strong persistence is concentrated in Shandong and Hebei regions,which indicates that the variation trend of sulfur dioxide concentration in most regions of China will continue the past trend.The results show that the atmospheric sulfur dioxide concentration in the north China plain and Chongqing will decrease in the future,while that in most other regions will remain basically unchanged.(5)Meteorological conditions,vegetation,topography and socio-economic factors will all have an impact on atmospheric sulfur dioxide column concentration.The correlation between the annual mean concentration of sulfur dioxide column and the annual mean value of temperature,precipitation and NDVI was both positive and negative,and the negative correlation distribution area was large.The linear fitting results of air temperature,precipitation and sulfur dioxide column concentration all show significant negative correlation,which indicates that air temperature and precipitation have great influence on the distribution of sulfur dioxide.Topography and wind direction also have important effects on the spatial distribution of atmospheric sulfur dioxide concentration.Social and economic factors,sulfur dioxide emissions in the second industry accounted for the proportion of GRP,coal consumption and column has significant correlation between the concentration of sulfur dioxide,sulfur dioxide emissions and secondary industry accounted for the proportion of GRP correlation coefficient is 0.9 between column and sulfur dioxide concentration,artificial factors on the column atmospheric sulfur dioxide concentration changes play an important role.