A Case Study of a Severe Dust Storm Resulted from a Explosive Mongolia Cyclone
蒙古气旋爆发性发展导致的强沙尘暴个例研究

On April 6 to 7 of 2001, a severe dust storm occurred in North China.A preliminary study was conducted on the sand\|dust source, the formation of arid environment, the physical cause of Mongolia cyclone explosive development and the process that sand\|dust were blown and raised. The study uncovered the close relationship between the dust storm,Mongolia cyclogenesis and the upper level jet. Results showed:the primary sand\|dust sources came from Badain Jaran desert and Hunshandake desert in western and mid Inner Mongolia respectively; the weather without precipitation lasting a long period caused a dry climatic background of the severe dust storm; the explosive development of Mongolia cyclone and the strong surface wind caused by the cold front passage induced the dust storm; the physical cause of the upward transportation of large amount of sand\|dust lay in factors as follows: the turbulent mixing resulted from both the dynamic and thermal instability in the planetary boundary layer, and the strong/ dry/ ascending motion formed by coupling the cold frontal lifting in the low atmosphere with the divergence forcing which located at the left side of the upper\|level jet exit region in the upper atmosphere. The authors think that the severe dust storm is a strong/ dry /convective storm carrying a large amount of sand\|dust.