Analysis of Nighttime Drainage Wind in the HEIFE Region

Abstract

When the influence of a synoptic system is weak, nighttime drainage wind often occurs along the front range of the Qilian Mountains, the southwest fringe of the Hexi Corridor, which blows to the gobi (rock desert). The features of the drainage wind were analyzed using the data from two meteorological stations at the foot of the Qilian Mountains. The maximum wind was found at the 8m level and the depth of the flow was shallow. The flow dissipated quickly over the oasis. A sudden decrease in air temperature was observed below the 10m level, associated with the passage of the leading edge of the drainage flow. The upward momentum flux and the downward heat flux due to the turbulence increased just when the leading edge of the flow was passing.