Study On The Characteristics Of Smog Transports In Central And Eastern China Based On Integrated Remote Sensing And Model Simulation

In recent years,severe smog pollution incidents have occurred frequently in the central and eastern regions of China,and the primary pollutants are mostly fine particles.The causes of smog are mainly divided into three types:adverse weather conditions,the impact of local emissions and regional transmission.Studies show that reducing regional transmission is an effective way to reduce the occurrence of smog.Carrying out regional transmission research on PM_2.5.5 during smog pollution and exploring the rules of smog transmission will provide a strategy for coping with heavy smog pollution events in the central and eastern regions.Scientific basis.In this study,Xuzhou and its surrounding areas were used as research objects.The ground laser radar and CALIPSO satellites were used to monitor the vertical distribution of aerosol particles in the two haze events in December 2014 and January2015.The CMAQ model was used to analyze the haze events.The transmission characteristics of PM_2.5.5 and its components in the central and eastern regions were quantitatively analyzed based on the CMAQ-ISAM source analysis tool for the sources of PM_2.5.5 contribution in Xuzhou.The research results show that:1)Ground lidar monitored that the aerosol input aerosols were transmitted down to the planetary boundary layer in the early morning on December 2,2014 and January 3,2015,and the aerosol concentration increased below 0.5 km in the afternoon.2)The ground lidar and CALIPSO satellites monitored that the aerosol input aerosols were transmitted down to the planetary boundary layer at 5:00 on December 2,2014 and 5:00 on January 3,2015.Most of the aerosols were polluted dust.3)Use the CMAQ-ISAM tool to analyze the source of PM_2.5.5 in Xuzhou.During the two events in December 2014 and January 2015,the main source of PM_2.5in Xuzhou was during long-distance transmission and local emissions.In addition,it is most affected by civil and industrial sources,and the sulfate content in PM_2.5.5 is the largest.4)The CMAQ model was used to simulate the transmission of PM_2.5components at a high-altitude imported aerosol（at 1.5 km）in central and eastern China.During two haze events,the sulfate concentration in the high-altitude input aerosol at 1.5 km Maximum,with the highest sulfate and nitrate concentrations near the ground.CMAQ was used to simulate the changes in PM_2.5.5 and its components at different altitudes over the CALIPSO satellite transit trajectory.The high-altitude imported aerosols from the two haze events came from more than 3 kilometers,of which the sulfate concentration was the largest,and the elemental carbon and Organic carbon had no significant effect onPM_2.5.5 near the ground.