Study on the vertical distribution and transport of dust aerosols during typical dust weather events in the Tarim Basin,Northwest China in spring,2021
Based on lidar observations combined with ERA5 reanalysis data,HYSPLIT trajectory model,environ-mental monitoring data and meteorological observations,we studied the vertical distribution of optical properties of dust aerosols in the Taklamakan hinterland in spring 2021.The formation,development processes,potential sources and transport pathways of large-scale aeolian dust weather in Tarim Basin were analyzed and discussed.The results showed that two strong dust processes occurred in the desert hinterland from 20:00 on April 19 to 14:00 on April 21 and from 14:00 on April 22 to 18:00 on April 26.Large amount of suspended dust particles were de-tected at the height of 0-5 km over the atmosphere.The extinction coefficient was above 0.3 km-1,within 2 km of the surface,and the depolarization ratio was more than 0.6,which was much higher than the threshold value of 0.31.These two dust events were both affected by the low trough in the upper air and the ground cold air.The first dust weather event was mainly caused by cold air crossing over the Tianshan Mountains.Blowing dust weath-er occurred in Kashgar,Hotan and Aksu.The PM10 concentration in Hotan reached a peak of 3763µg·m-3on April 22.And the dust source was from the western of the basin.The second dust weather event primarily resulted from cold air entering the basin from the northeast.The PM10 concentration in Korla and Aksu cities increased sharply to 1200µg·m-3 from 25 to 26,April.Dust particles originated from the local sand,northeastern and northern of the ba-sin.During the second dust weather process,dust particles were blown up and transported higher than before,and the air pollution lasts longer and is more widespread.The windblown dust can suspend above 4 km height during dust processes.The particles transport height was significantly higher than high-frequency areas of dust weather in Hotan and Minfeng.
万方数据
维普
