Long Time Series Region AOD Remote Sensing Monitoring With Spatial And Temporal Characteristics Of The Study

Aerosol Optical Depth（AOD）is an important parameter for the detection of climate and environmental change,monitoring of environmental pollutants and sources and spatial and temporal character over long time series in a region.Remote sensing monitoring and temporal characterization of regional AOD over long time series using aerosol data products is a current hot direction.This study uses the MCD19A2＿1KM aerosol data product with a multi-angle atmospheric correction algorithm to inverseperform AOD through geographic correction,AOD quality determination and masking,and stitching and cropping of the study area,etc.The effects of human activities,natural environmental changes and major events on the spatial and temporal changes of AOD are investigated.The study shows that:（1）In the study to analyze the influence of human activities on aerosols,Wuhan city was selected as a typical representative study area.It was found that there was no significant change in the mean AOD values during the same time period before and after the closure of Wuhan,but the spatial characteristics changed significantly,and the area of high AOD values showed a change from west to east.In the past five years,the AOD values in Wuhan showed a continuous decreasing trend from March to July and an increasing trend from July to December.AOD values in Wuhan are higher in spring and winter;lower in summer and autumn.The annual average values generally show a slow decreasing trend.（2）The Mu Us Desert was selected to study the impact of the natural environment on aerosols,with the majority of the ground cover changing from sand to vegetation and significant changes in natural factors.In the analysis of the 20-year study,it was found that the mean AOD values in spring and summer were generally decreasing,with a more pronounced decrease in summer and no significant change in autumn and winter.In a comprehensive analysis of the annual mean AOD values in the Mauves,it was found that there was a general downward trend in the annual mean values,with an increase in vegetation cover leading to a decrease in aerosol content.The years with an increasing trend in annual mean values are 2009-2011 and 2016-2021.2006-2009 and 2011-2014 show a decreasing trend.The highest mean values were recorded in 2011 and the lowest in 2014.（3）The DPRK nuclear test area was chosen as the study area for aerosol changes from major events.In this study,aerosol values could be detected more significantly in three of the six North Korean nuclear tests.This indicates that special military activities have caused some influence on AOD.This study analyzes and investigates the long time series remote sensing monitoring and spatial and temporal characteristics of AOD from human activities,natural factors and major events respectively,which provides guidance and examples for subsequent aerosol studies in similar regions.It helps to learn to grasp the main characteristics of the temporal distribution changes and spatial distribution of aerosols.