Interaction of Surface Heating, the Tibetan Plateau Vortex, and a Convective System: A Case Study

Using the National Centers for Environmental Prediction Final Analyses (NCEP-FNL) reanalysis data, the temperature of black body (TBB) data from the Fengyun-2E (FY-2E) satellite, and the Climate Prediction Center morphing technique (CMORPH) precipitation data, the effects of surface heating on the genesis and development of a convective system over the Tibetan Plateau (TP) in late June 2012 are analyzed on the basis of thermodynamic and dynamic diagnosis and numerical simulation by employing the WRF model. Results indicate that surface heating over the western and central Tibetan Plateau plays an important role in the genesis, enhancement, and eastward propagation of the TP Vortex (TPV). During the development phase, the TPV triggers the genesis of a convective system over the eastern TP by strengthening the convergence belt between the northerly and southerly flows. Meanwhile, strong condensation heating, released by the convective precipitation, reinforces the TPV. Therefore, a positive feedback mechanism exists between the surface heating, the TPV, and the convective system. Results from numerical simulations further reveal that, in addition to the appropriate background circulation, the surface latent heat flux over the eastern TP can induce an unstable state in the low level atmosphere. This provides energy for the development of convective systems, which can then generate a suitable thermal environment for organized convective precipitation.