Studying The Regional Transmission Of Fine Particulate Matter Based On Multi-Source Observation

With the rapid development of urbanization and industrialization in China,people's living standards continue to improve,however,more and more environmental problems have emerged,especially fine particulate matter pollution,which seriously threatens environmental quality,human health,effects the solar radiation directly or indirectly,and gradually become the focus of research in the field of atmospheric environment.Atmospheric fine particulate matter pollution in China mainly presents obvious regional composite pollution characteristics,and the regional transmission characteristics of pollutants bring new challenges for the regulation and control of air quality.Aiming to solve problems of low simulation accuracy and insufficient evaluation ability of traditional methods,this study fully considered the advantages of satellite remote sensing,such as its large observation range,short revisit period,and high data quality,and established a set of methods for research of atmospheric fine particulate matter pollution regional transmission based on multi-source observation data,which combined with ground monitoring data,ERA 5 reanalysis data,HYSPLIT(Hybrid Single Particle Lagrangian Integrated Trajectory)backward trajectory data and atmospheric three-dimensional monitoring navigation data.This method can be used to identify regional transmission events of atmospheric particulate matter,reconstruct the transmission channels,what's more,the characteristics of horizontal transmission and vertical diffusion are also be analyzed by this method.First of all,this study inverted hourly aerosol optical depth considering the BRDF based on the data from the Himawari-8 geostationary satellite AHI(Advanced Himawari Imager)sensor,which was launched by the Japan Meteorological Agency.The accuracy verification was carried out with AERONET Level 1.5 data as the true value,and the correlation coefficient R of the aerosol optical depth inversion results used in this paper reached 0.84 and 0.83 respectively in the two stations in the North China Plain.Further,the geographically weighted regression algorithm was used to estimate the concentration of fine particulate matter near the ground with high accuracy combining with meteorological data such as wind speed,wind direction,relative humidity and planet boundary layer height(Hourly correlation coefficient R: 0.84,daily:0.87).These results can provide reliable and effective remote sensing data for the study of regional transmission of fine particulate matter.Furthermore,this article proposes to use satellite remote sensing data as the basis to identify regional transmission events of atmospheric fine particles polluted through the temporal and spatial continuity changes of polluted pixels.With the help of this method,we effectively identified regional transport events of fine particulate pollution26 times in the North China Plain in 2019,and which mostly occurred in winter and spring in the North China Plain.Then,a method for reconstructing the transmission channel of atmospheric fine particulate matter by high-frequency aerosol optical depth observations was proposed,which effectively reconstructed the transport channels of the whole layer of atmospheric fine particulate pollution in the period of high incidence of regional pollutant transmission in 2019,and accurately analyzed the transverse and longitudinal distances covered by the pollutant transport channels.In order to identify the altitude layer where the pollutant transport channel located,this study proposed to analyze the altitude layer of the pollutant mass by comparing the air pollutant transport channel of the whole layer through the clustering results of airflow at different altitude layers based on the HYSPLIT backward trajectory.Based on the analysis of horizontal transmission characteristics of fine particulate matter which combined with the reconstruction of pollution transmission channel and the calculation of pollution air mass transmission speed,and the analysis of vertical diffusion characteristics which combined with the variation of pollutant diffusion time at different altitude layers.This study also introduced atmospheric three-dimensional navigation detection technology to track the transmission process of atmospheric fine particulate matter polluted areas.The pollutant concentration profile analysis was carried out through lidar,and the pollution source,pollution height were dynamically monitored in combination with remote sensing data and backward trajectory data.In the process of fixed-point vertical detection,this study combined the meteorological data detected by the vehicle-mounted meteorological instrument and the profile data detected by the microwave radiometer,preliminary exploration of the cause of the transmission of atmospheric fine particulate matter in the polluted area was carried out.Through the method for research of atmospheric fine particulate matter pollution regional transmission based on multi-source observation data proposed in this study,it is possible to conduct a comprehensive and multi-level discussion and analysis of air pollution and regional transmission in various places.The results can provide an effective data basis and reference basis for the comprehensive management of environmental pollution and joint prevention and control policies.