Estimation Of The Relationship Between AOD And PM_2.5 And Analysis Of The Distant Source Transport Trajectory

The components with aerodynamic diameter less than 2.5?m in aerosols are called fine particles(PM_2.5).The PM_2.5 is one of the main reference objects for air quality assessment.The rapid development of remote sensing technology provides a new method for monitoring PM_2.5 concentration.In this paper,the aerosol monitoring products based on CE318 inversion of solar photometer are used to analyze the aerosol characteristics combined with the topography and climate characteristics of Guilin.The estimation model of PM_2.5 concentration based on the aerosol optical depth is established.According to the complete pollution process of the monitoring area,the main source direction of aerosol is discussed combined with the backward trajectory model.The main works of this paper are as follows:?1?The aerosol products obtained from the inversion of the CE318 monitoring data combined with regional climate conditions were used to analyze the aerosol optical properties.The peak of aerosol optical depth in Guilin was reached in summer The reason is that the high temperature and rainy climate in summer will condense fine model aerosols.the relatively dry winter is,the small content of water vapor column is,and the absorbent aerosols produced by coal from the north in winter are the main reasons for the low single scattering albedo;The fitting analysis of long index frequency ration shows that the main particles in Guilin are fine particle aerosols.?2?through statistical analysis of aerosol optical depth data of CE318,boundary layer height data of lidar and PM_2.5 data of China Environmental Monitoring Station during the period from 2017 to 2018,the correlation between aerosol optical depth and PM_2.5concentration is high and stable.Meteorological factors were added to modify the fitting estimation model of single-factor variables of aerosol optical depth and PM_2.5concentration,and the fitting correction model of multi-factor variables was established.Based on the PM_2.5 concentration monitored by China Environmental Monitoring Station,the multi-factor variable model was compared with the PMRS model combining fine model aerosol particle ratio and boundary layer height,the optimal model was determined to fit the multi-factor variable model.?3?According to the concentration of PM_2.5 and air quality standards of Guilin provided by China Environmental Monitoring Station,the pollution trend and pollution degree in Guilin are analyzed.For the typical pollution process time period,the GDAS satellite data combined with the backward trajectory analysis model are used to make the backward trajectory clustering analysis.The results of backward trajectory cluster analysis show that the local area is mainly affected by the heavy industrial cities in the north and Southeast.But in the season of prevailing south wind,the clean air in the coastal area makes the air better in Guilin.The research work in this paper provides support for the study of aerosol characteristics and environmental monitoring in Guilin,provides reference for the ground-based remote sensing research of particulate matter,and also provides basic data for the application and development of ground-based monitoring networks in China.