Topographic Sensitivity Test of a Typical Rainstorm Process in Qiandongnan Prefecture of Guizhou Province
To explore the influence of terrain on rainstorm.Based on WRF model and FNL reanalysis data,a typical rainstorm process that occurred in Qiandongnan Prefecture of Guizhou Province from June 17 to 18,2022 is numerically simulated and terrain sensitivity tests of Leigong Mountain and Moon Mountain are carried out.The results show that the WRF model can well simulate the area and intensity of the severe precipitation process.The convergence and uplift of the shear line in the upper trough and the lower layer,and the abundant water vapor brought by the southwest jet stream led to the occurrence of this rainstorm process.The terrain sensitivity tests indicate that as the height of Leigong Mountain decreased,the integrated atmospheric wet layer decreased,the water vapor convergence weakened,the vertical motion weakened,and the CAPE value in the south increased,which caused the precipitation center to shift southward and the precipitation to decrease by more than 35%.The reduced height of Moon Mountain,combined with favorable terrain in the downstream direction,resulted in enhanced water vapor convergence in the southwestern region,strong convective development,and thick upward motion layers.The weakened CAPE in the southeastern region drove the center of heavy rainfall to move southward and westward,resulting in an increase in precipitation of over 35%.The decrease in terrain height could cause the changes in the position and intensity of weather systems at different altitude levels,weakening the airflow convergence at 850 hPa and displacing the trough at 700 hPa,thus resulting in reduced rainfall and changes in precipitation zones.This method can effectively explore the influence of terrain on precipitation distribution and intensity,and can be used for effective correction of forecast results in business.
Qiandongnan Prefecturerainstormterrainnumerical simulationsensitivity test
NETL
NSTL
万方数据
