Temporal And Spatial Distribution Characteristics Of Global Atmospheric Boundary Layer SO₂ Based On Remote Sensing Data

The atmospheric environment is the basis for human survival.Since the industrial revolution,the rapid development of global industry,humans have discharged a large number of atmospheric pollutants into the air.The traditional atmospheric pollutant SO₂is the main precursor of haze and acid rain.It is also an important contributor to near-surface O₃ pollution.At the same time,SO₂ has a strong absorption on the ultraviolet,which seriously affects the distribution of solar radiation on the earth,thus affecting the atmospheric circulation in local and global,so it is necessary to make a study on the atmospheric boundary layer SO₂ in spatial and temporal distribution and its changes.This paper uses the remote sensing data from 2005 to 2017 to study the temporal and spatial distribution characteristics of global atmospheric boundary layer SO₂.The experimental results show that:?1?SO₂ is prone to sedimentation in high temperature and high humidity areas.It is not conducive to extract of PBL SO₂.Cloudiness leads to the lack of SO₂filtering of cloud parameters recommended by official,resulting in poor correlation between from ground-based and remote sensing.Multi-smog and high-concentration near-surface O₃will also affect the extraction of PBL SO₂.?2?SO₂ columns in the atmospheric boundary layer present spatial heterogeneity in space,the six-and seven-level high-columns show a clustered distribution,mainly concentrated in natural source regions and nearby represented by volcanic eruptions and industrial emissions represented by anthropogenic sources.Globally,the atmospheric boundary layer SO₂ exhibits latitudinal zonal distribution characteristics.The monthly average SO₂ columns in the same latitude area is similar and has similar intra-annual variation trend.Some areas are affected by terrain,and there will be a large change in winter.The rest of the season is similar or identical to the trend of urban latitude.?3?From 2005 to 2017,the annual average columns of global SO₂ cell grids increased first and then decreased.The maximum occurred in 2011 by volcanic eruptions.Due to the difference of sensors,it shows a significantly decrease in 2015.In terms of seasonal changes,volcanic eruptions led to significant mutations in the summer of 2008,2009,and 2011,and the rest of the seasons did not change any more.In terms of monthly average change,the unit grid SO₂ of monthly mean columns in the atmospheric boundary layer showed a wavy trend from 2005 to 2017.Under normal conditions,the maximum appeared in summer and the minimum appeared in winter.?4?Global variation of SO₂ in the atmospheric boundary layer,with the direct solar radiation point travels between the North-South tropic,the latitude of the first-order SO₂ columns latitudinal symmetry axis,except for October to December,are corresponding to the solar direct radiation points On the 15^th every months.?5?This paper selects the Chinese region to study the non-zonal distribution of SO₂in the atmospheric boundary layer,and finds that the monsoon has a great influence on the spatial distribution and temporal variation of SO₂ in the atmospheric boundary layer of different regions.?6?In terms of impact factors,temperature and pressure are the most important factors affecting the SO₂ columns of the atmospheric boundary layer,followed by precipitation,sunshine hours,maximum wind speed,wind speed and relative humidity are seldom influenced on SO₂.