Research On The Temporal And Spatial Distribution And Influencing Factors Of Xinjiang Aerosol Optical Thickness From 2001 To 2017

In recent years,the problem of atmospheric environmental quality has become increasingly serious.The problems of poor air quality and low visibility in various regions of Xinjiang have seriously affected people's lives.AOD is subject to complex diversity and inhomogeneity due to the influence of surface human activities and the type of underlying surface.Studying the spatiotemporal distribution of aerosol optical thickness through a large amount of data helps to grasp the distribution law of AOD and plays an important role in monitoring and predicting atmospheric particulate pollution.In this study,the first is to use the MODIS-Terra dataset MOD04₃ KM aerosol product,the monthly data to obtain the maximum monthly data,and then the 12-month monthly data to obtain the average annual data.The spatial distribution characteristics of AOD and the characteristics of interannual,intertemporal and seasonal variations in the study area were analyzed.The temporal and spatial distribution characteristics of aerosol optical thickness in Xinjiang in the past 17 years were analyzed and compared.Afterwards,using MODIS1 B-level data MOD021 KM daily data to reflect the AOD spatiotemporal dynamics during a severe haze weather in Urumqi in early 2016,combined with meteorological data and using the backward airflow trajectory analysis model,the pollutants spread over Urumqi during this period.The process was analyzed,and the source and destination of atmospheric particulate matter during the weather process were analyzed.Finally,the calculated AOD data of the 2001-2017 study area was used,combined with meteorological data from the website,MODIS-NDVI?MOD13 A3?.Mean NDVI data,DMSP-OLS 2013 F18 global nighttime lighting data,stable lighting image data resolution is 30",and the economic development data,population and environmental pollution data in the Xinjiang Statistical Yearbook,analysis and various The relationship between influencing factors and AOD.The results of this study are as follows:?1?In the past 17 years,the annual average AOD variation range in Xinjiang ranged from 0.2 to 0.4.In 2001,the annual average of AOD was the highest,and it was the lowest in 2017.In 2006 and 2010,the average annual AOD peaked.In spring,the AOD was the highest in March and April,and then gradually decreased.The high value of AOD is mainly in the space north of the Tianshan Mountains,Bole,Kashgar and the southwestern edge of Taklimakan.?2?In 2016,a serious ash weather situation in Urumqi showed that the overall distribution trend of AOD in Urumqi was higher in urban areas than in suburbs.Generally speaking,the terrain is low in the central and northern regions,and the terrain is high in other directions.In addition,the wind speed is affected by meteorological factors such as temperature,so that the aerosol in Urumqi continues to accumulate and is not easy to spread around,and the AOD value is often high.The situation arises.Compared with other seasons,Urumqi will have an inversion layer in the winter atmosphere,and a thicker inversion layer and a longer maintenance time will also hinder the diffusion of pollutants in the atmosphere.The whole city is showing an increasing trend from north to south.?3?The correlation between AOD and various meteorological elements is as follows: precipitation > sunshine hours > average temperature > average wind speed > relative humidity.These meteorological factors have different effects on Xinjiang's AOD.On the northern slope of the Tianshan Mountains,Urumqi is the core and the surrounding cities are important industrial cities in Xinjiang.The average annual AOD of the regions with rapid economic development is also high.The influence of elevation is mainly that AOD is higher than the middle of the basin at the edge of the two basins in Xinjiang,and the AOD value is also higher in the Pamirs and Altai Mountains.By comparing the city's nighttime lighting data with the AOD data,it can be seen that the AOD value of the population and economically developed regions will also increase.