塔里木盆地西部大气边界层特征及其与沙尘污染的关系OA

Based on sounding data and conventional ground-based observations from 2010 to 2023 in Kashgar,the mixed layer height,inversion layer characteristics,and boundary layer ventilation were calculated using the dry adiabatic method.The relationships between boundary layer meteorological parameters and pollutant concentrations under different dust conditions were investigated.The results indicate that there is a significant seasonal variation in the mixing layer height and ventilation coefficient.The mixing layer height is highest in summer(3 589 m),the ventilation coefficient is largest in spring(17.28×103 m2·s-1)and lowest in winter.Temperature inversions are frequent and strong in winter and weakest in summer.Air quality has improved year by year,with the proportion of days with good air quality increasing to 51%,and heavy pollution days decreasing by 18%.During spring dust storms,PM10 and PM2.5 concentrations are highest,reaching 1 157 and 354 μg·m-3,respectively,which are 2 to 5 times higher than non-dust days.In winter,the compliance rate of PM2.5 is lower than that of PM10,and PM2.5/PM10 ratio exceeds 40%,indicating that fine particulate matter pollution is more severe compared to other seasons.The concentration of particulate matter is significantly negatively correlated with the mixing layer height and ventilation coefficient.During spring dust storms,low temperatures,low humidity,and relatively high wind speeds promote dust dispersion.To address severe fine particulate pollution in winter,it is recommended to adopt clean energy alternatives and implement joint dust storm prevention measures.