Calibration And Application Research Of Himawari-8 Aerosol Optical Depth Product

This paper verified and corrected the Himawari-8 high time resolution aerosol optical thickness product released by the Japan Meteorological Agency.The variation rule and characteristic relationship among aerosol optical thickness,particle concentration and visibility were studied.Finally,the feasibility of the corrected AOD inversion PM_2.5 and visibility is analyzed.The main contents and conclusions of this paper are as follows:?1?Level 2 bet Aerosol Optical Depth?AOD?dataset from Himawari-8?H8?satellite was compared to the AOD observed at eight typical sites in Eastern China,a high aerosol region,in 2016.Although,there was a good linear correlation between the H8 AOD and observed AOD,H8 AOD was generally underestimated by 37%⁴6%in this region.The statistical absolute error of H8 AOD rose linearly with the observed AOD increasing,and there was an excellent correlation between the absolute error and the AOD.The absolute error of H8 AOD symmetrically increased by 0.05 with increasing of the 0.1 observed AOD,which was a span error for H8 AOD.Based on the absolute error linear regression equation?y=-0.53x+0.05?,a span error correction was carried out in the region.The accuracy of the corrected H8 AOD was increased significantly with the absolute error decreasing by 44%.The corrected satellite inversion data is closer to the ground-based observation data,which improves the applicability and reliability of H8 AOD products in eastern China and can be used to evaluate the spatial and temporal distribution of AOD in the eastern region.?2?The synchronous observation?2013.06-2017.05?data of PM_1.0,PM_2.5,PM₁₀,AOD and Visibility in Beijing show that the concentrations of PM_1.0,PM_2.5 and PM₁₀have decreased 8,16 and 32 ug/m³ respectively over the past four years.The vertical and horizontal visibility of the atmosphere has been improved,with Visibility rising by2.1 km and AOD decreasing by 0.19.Under different atmospheric conditions,good mutual characterization relationship can be established between Particulate matter concentration?PM?,AOD and Visibility.When Visibility=10km is used as a standard,PM and AOD have a sensitive threshold of Visibility.The PM threshold range is as follows:PM_1.0:36²5,PM_2.5:72⁵0,PM₁₀:158⁶6,and the AOD threshold range is0.93⁰.32.With the increase of relative humidity,the thresholds of PM and AOD decreases gradually.Aerosol vertical extinction AOD and horizontal extinction Visibility have an exponential relationship.?3?The feasibility of inversion of PM_2.5 and visibility by H8 AOD after correction is analyzed by using AOD,PM_2.5,visibility and meteorological data from Beijing ground observation.The results show that there is a good correlation between inversion values and ground observation values,but there are obvious differences among different inversion methods.The seasonal-based nonlinear regression model has better results in inversion of PM_2.5 than the linear regression model.The PM_2.5 inversion by both methods has obvious underestimation.Season-based regression models based on least squares regression model have better inversion results than single-variable parameters.The correlation between the inversion Visibility Based on least squares regression model and the ground observation value is the best,but the fitting function is poor.The fitting function between the visibility data and the observation data based on the aerosol elevation estimation model and the seasonal regression model inversion is better,but the correlation between the data of the two inversion methods and the ground data is poor,and the points are discrete.In this paper,the accuracy evaluation and calibration of Himawari-8 satellite optical thickness products are carried out,which provides basic information for the improvement and perfection of Himawari-8 AOD product algorithm.Due to the large uncertainty of satellite AOD inversion of particulate matter concentration and visibility,the correlation between AOD,particulate matter concentration and visibility and the influence of meteorological elements on its correlation are critical to satellite remote sensing air quality.The calibrated H8 AOD product can be used to invert particulate matter concentration and visibility,increasing the diversity of particle concentration and visibility data.