Observational Experiment on Generation and Development of Summer Orographic Cloud during the Southwest Air Current Pattern in Qilian Mountain
The summertime orographic cloud evolution under the southwest air current pattern condition has been analyzed and the concept model of orographic cloud development and evolution has been obtained based on the analysis of the dataset observed in Qilian Mountain during the summer of 2007. The primary results include: (1) The water vapor of orographic clouds under the southwest air current pattern condition is mainly located in the heights of 3500～6500 m (ASL), and moved from south to north of Qilian Mountain by the southwest air current in the mid troposphere through the dynamic mechanism. (2) The water vapor in Qilian Mountain is abundant under the condition of southwest air current pattern, and lifting condensation and free convection levels are both lower. The convection cloud prone precipitation will be generated while the wet air parcel is lifted to condensation level and the convection potential energy available released. (3) The confluence updraft will occur at each peak of Qilian Mountain as the up-valley winds on the both sides of peak during daytime, and the meso-β scale convective cloud bands, which are arranged along the peaks, are formed after the wet air parcels lifted by multitudinous up-valley winds, then these clouds moved to the north side of the Qilian mountains by the southwest air current aloft. It is one of the reasons why the precipitation on the north side is more than that on the south side.
Qilian mountainSouthwest air currentOrographic cloudObservational experiment
NETL
NSTL
万方数据
维普
