Abstract: A typical regional sand-dust weather event over the eastern margin of the Tarim Basin was analyzed and the reason of dust hover and transport characteristics were also explored using the surface meteorological data,sounding observations,and National Centers for Environmental Prediction (NCEP) reanalysis data.The results showed that the intense development of a thermal depression in the southern Xinjiang Basin and abnormal high temperature provide dynamic and thermodynamic conditions for the occurrence of sand-dust event.During the maintenance of floating dusty weather,the near-surface layer in the Tarim Basin is characterized by stable stratification and weak vertical turbulence.The temperature difference of the inversion layer has a good correspondence with visibility,and the thickness of the inversion layer varied little.During the strong sand-dust weather,the temperature gradient in the inversion layer increases and the subsidence of floating dust particles occurs as the thickness of surface inversion layer becomes thinner,which leads to a higher visibility.When the dust storm turns to floating dusty weather,the temperature difference and thickness of the inversion layer increases significantly.When the dust storm moving path passes through two key regions including the southwest and the southeast regions of Korla,it probably affects the dust weather over the Korla region,while the particles moving along the eastern path will reduce the floating dust over the Korla region.Due to the effect of the geographical environment of Ruoqiang area,the northeast,southwest,or west paths can cause sand-dust weather over the Ruoqiang area.

Key words: Sand-dust, Thermal depression, Thermal inversion layer, Backward trajectory, Tarim Basin