南疆地区不同类型沙尘天气及相关因素对气溶胶光学厚度影响研究

Study on the influence of different types of dusty weather and related factors on aerosol optical thickness in South Xinjiang region

为探究南疆地区沙尘气溶胶光学厚度(Dust aerosol optical depth,DOD)的时空分布特征及影响因素,基于遥感数据与气象站观测资料探讨了南疆地区2003—2019年期间DOD的时空分布特征,并分析了不同类型沙尘天气与非沙尘天气及其他相关因素对DOD的影响.结果表明:①南疆地区DOD值与沙尘天气日数分布呈显著的空间差异,塔克拉玛干沙漠东部的DOD峰值达0.21,塔克拉玛干沙漠南缘年均沙尘天气日数高达90 d以上.②不同类型沙尘天气与非沙尘天气的DOD值大小排序依次为:沙尘暴(0.10~0.71)>浮尘(0.24~0.44)>扬沙(0.13~0.47)>非沙尘日(0.08~0.11).③从年际变化来看,非沙尘天气、浮尘天气及扬沙天气的DOD值有减小趋势,而沙尘暴天气的DOD值有增大趋势,各沙尘天气日数也有增多的趋势;DOD最高值出现在3—5月,浮尘天气3月最多,扬沙与沙尘暴天气5月最多.④相关性结果表明,土壤体积含水量、相对湿度、最大风速对DOD值的影响最为显著;DOD与影响因素之间的拟合关系表明:DOD与土壤体积含水量、水汽压、相对湿度的拟合关系呈线性负相关,DOD与平均气温、最大风速的拟合关系呈“抛物线”型曲线.

In order to investigate the spatial and temporal characteristics of dust aerosol optical depth(DOD)and the factors affecting it in the southern Xinjiang region,the spatial and temporal evolution of DOD in the study area over the past 17 years was investigated based on remote sensing data and meteorological station observations,and the effects of different types of dusty and nondusty weather and other related factors on DOD were analyzed.The results showed that:there were significant spatial differences in the distribution of DOD values and dust weather days in the southern Xinjiang region,with a peak DOD value of 0.21 in the eastern part of the Taklamakan Desert,and an annual average number of dust weather days of up to 90 days or more in the southern edge of the Taklamakan Desert.The order of DOD values for different types of dusty and non-dusty days was:dust storm days(0.10~0.71)>floating dust days(0.24~0.44)>blowing sand days(0.13~0.47)>non-dust days(0.08~0.11).In terms of inter-annual variation,there was a decreasing trend in the DOD values for non-dusty,floating dusty and sandy weather,while there was an increasing trend in the DOD values for dusty storms and an increasing trend in the number of dusty weather days;the highest values of the DOD were found in the months of March to May,with floating dust weather being the most frequent in March,and sandy and sandy storms being the most frequent in May.The correlation results found that soil volumetric water content,relative humidity,and maximum wind speed had the most significant effects on the DOD values;the fitting relationships between DOD and the influencing factors showed that DOD was negatively and linearly correlated with soil volumetric water content,mean vapor pressure,and relative humidity,and that DOD was parabolically correlated with mean air temperature and maximum wind speed.