A comparative study of two extreme dust events in the deserts and gobi regions in the arid regions of northwest China
In order to deeply understand the evolution and driving factors of extreme dust events,two dust storm events that erupted in the deserts and gobi regions in the arid regions of northwest China on 31 March 2007("3·31"dust event)and 14 March 2021("3·14"dust event)were selected,and their temporal and spatial evolution,high and low altitude circulation configuration,and changes in near-surface meteorological elements were compared and analyzed based on multi-source satellite remote sensing and reanalysis data.The results are as follows:(1)Both extreme events occurred in the Taklimakan Desert and the Gobi Desert,respectively,and they were influ-enced by upper-and-lower weather systems.The"3·31"dust event was influenced by a surface cold front and a ridge at high altitude.The northwesterly winds in front of the ridge,in cooperation with the vertical motion caused by the cold front,transported dust down-stream.The"3·14"dust event,on the other hand,was influenced by a Mongolian cyclone and an upper-air trough.The northwesterly winds following the cyclone,along with the vertical motion induced by the cyclone,swept up dust and transported it downstream through the northwesterly winds following the trough.(2)Both extreme dust events exhibited prolonged durations.The"3·31"dust event was influenced by the high-pressure ridge,a sea level pressure field with little variation and the surrounding topography.This configuration resulted in a stable atmosphere,preventing the deposition and transport of dust.Different from the event above,the"3·14"dust event was caused by the persistent high pressure over northern China,which led to southerly and easterly winds that pre-vented dust spreading downstream.(3)Before occurrence of the extreme dust events,both the Taklimakan Desert and Gobi Desert expe-rienced high temperature,less precipitation,and depleted soil moisture,which formed favorable dynamic conditions and material foun-dations,such as strong winds and dry soils,for the outbreak of the two dust events.
deserts and gobi regions in the arid regions of northwest Chinaextreme dust eventsweather system configurationnear-surface meteorological factors
NETL
NSTL
万方数据
