Study On The Mechanism Of Aerosol Radiative Effect In Typical Regions

Aerosols can affect the radiation income and expenditure of the earth gas system through direct or indirect action,called aerosol radiative effect,which usually has a heating effect on the atmosphere and a cooling effect on the surface,with great uncertainty.In order to reduce the uncertainty of quantification of aerosol radiative effects,the study of aerosol radiation characteristics based on various remote sensing data has been one of the research priorities in this field.In this paper,the performance evaluation system of different satellite remote sensing aerosol products under the condition of air pollution is first considered,and the data of Moderate-Resolution Imaging Spectroradiometer(MODIS)aerosol products under different background conditions of air pollution are analyzed and verified.Secondly,based on MODIS data,the method of calculating the assessment of aerosol direct radiative forcing at the regional scale is improved,and the aerosol direct radiative forcing under different background conditions of air pollution in typical region(Beijing)is calculated.Finally,the aerosol optical characteristics,the characteristics of aerosol direct radiative forcing and the aerosol direct radiative forcing efficiency in typical regions are studied.The findings indicate:(1)Ground-based observation data in typical region shows that the annual average aerosol optical depth is from 0.757 in 2015 to 0.497 in2020,and the distribution of regional average aerosol optical depth based on MODIS data shows a similar downward trend.(2)With the deepening of pollution degree,the validity of MODIS satellite data is getting higher and higher,and it is gradually approaching ground-based observations,the correlation coefficients all reach 0.9.From no pollution to serious pollution,the aerosol direct radiative forcing range from24.2 to 92.3 W/m~2,-37.8 to-184.5 W/m~2 at the bottom of the atmosphere,and-13.6 to-92.2 W/m~2 at the top of the atmosphere in typical region(Beijing).(3)From high elevation to low elevation,aerosol optical depth increases from 0.08 to 0.8,and single scattering albedo increases from 0.86 to 0.93.Aerosol direct radiative forcing at the top and bottom of the atmosphere decrease with increasing elevation in typical regions;aerosol direct radiative forcing efficiency at the bottom of the atmosphere increases with the elevation of the typical regions,the trend at the top of the atmosphere is opposite to that at the bottom of the atmosphere.The research results of this paper can provide certain references for air quality,high-precision environmental monitoring,air pollution control,climate change,solar energy utilization and other fields.