Retrieval Of Aerosol Optical Depth Using Geostationary Satellite Images Based On Time Variation Of Ground And Atmosphere

As an important part of the atmospheric composition,aerosols have a significant impact on the Earth's atmospheric radiation balance and global climate change.This paper makes use of the high spatial and temporal resolution characteristics of GOCI data from geostationary orbit satellites to perform remote sensing research on aerosols in local areas.It can make up for the insufficiency of satellite remote-sensing observation data and thus more accurately reflect the dynamic changes of regional aerosols.It is important for tracking fast moving aerosols.First,we select Nanjing City as the study area for this article.Using the characteristics of multi-band and staring observations of GOCI data from geostationary satellites,combined with polar-satellite satellite-related products to study the characteristics of time-varying differences in surface and aerosols.Then according to different types of objects in the study area,specific geometric optical cores were selected for BRDF correction.Based on the multi-temporal data,the cost function was used to invert the aerosol optical thickness,and finally the accuracy test was performed.The results show that the GOCI data can be used for inversion of land aerosols,and both sites show high accuracy.The fitting degree of CE318 station Is 0.6444,and that of MOD04 is 0.7675,which shows good agreement compared with MODIS aerosol products.Compared with MOD04,it was found that although the overall trend of the spatial distribution is the same,the GOCI inversion results are more complete and have higher spatial resolution than the MODIS aerosol products,which is conducive to describing more details of the spatial distribution of aerosols.Secondly,according to the 2013 AOD inversion results of Nanjing City,the three-phase AOD monthly mean value and the AOD quarter average result are calculated according to different time scales.In terms of time distribution,although the monthly AOD monthly mean value changes at different times,the trend of monthly average AOD change at three times during a year is relatively consistent.The monthly AOD values are rising and falling alternately.The average of AOD images in the four seasons was in the trend of spring(0.3877)>summer(0.3493)>autumn(0.3272)>winter(0.2578),and the aerosol optical thickness in sunmer was more intense.In terms of spatial distribution,the high value distribution regions of the four seasons are different.Only the AOD value near the Lukou International Airport area in Jiangning District has been at a high value in the four images.Finally,for the daily 8-phase AOD results under clear skies in 2015,and the representative inversion results of January 1 and January 4 were given.In addition,the AOD change line chart of 8 different times per day for 12 days.The study found that although the AOD changes at different times of the day,the characteristics of intraday changes in aerosol optical thickness are obvious in a short time,and the curve is relatively consistent in the short term.At the same time,it is found that the aerosol products based on the GOCI data of the stationary satellite have the ability to monitor the diurnal variation of aerosol and provide the basis for the aerosol dynamic diffusion and the climate effect study.