Case Analysis on Two Low Vortexes Induced by Tibetan Plateau Shear Line
Using the NCEP/NCAR reanalysis data, the shear line over the Tibetan Plateau(hereafter Plateau) from 4 to 6 July 2007 are diagnostically analyzed, and two low vortexes induced by the shear line which cause moderate rain in central Plateau, the results show that the perpendicular transportation term and the horizontal divergence and convergence terms have played a major role in the development of the two vortex, in the different stages of the development of vortex, which have different contributions. At the same time, the contribution of horizontal advection has increased during the extinction phase. The results of apparent heat source and apparent moist sink suggest that the process of precipitation in convective precipitation, the negative center of vertical movement is corresponding to apparent heat source and apparent moist sink's, having same change trend, indicating that atmospheric heating is closely related to ascending motion during process of precipitation, the heating in middle troposphere causes pumping action in lower troposphere which can promote the development of plateau vortex, the condensation latent heat releasing is main heat source, moisture condensation plays a decisive role.
Tibetan PlateauPlateau low vortexShear lineBudget of vorticity
NETL
NSTL
万方数据
维普
