Effect of Atmospheric Heat Source on the Tibetan Plateau Vortex During Different Developmental Stages—A Case Study in July 2013

The Tibetan Plateau (TP) vortex (TPV) is the main precipitation system in summer over the TP and downstream regions. This study analyzes a TPV case from 19 to 21 July 2013, based on high-resolution ERA5 reanalysis, the temperature of black body (TBB) obtained from the Fengyun-2E (FY-2E) satellite, and precipitation amount from TRMM (Tropical Rainfall Measurement Mission). The TPV case keeps active on the TP for about 56 h, which can be divided into three stages: Initial, development, and moving-out. Further, the roles of atmospheric heat sources in TPV during different stages and the related mechanisms are investigated. The results show that the TPV intensity increases with fluctuations. Furthermore, by diagnosing the potential vorticity (PV) tendency equation, it was found that the vertical gradient of diabatic heating is the main factor causing TPV development, i.e., a positive (negative) PV is produced below (above) the height where the maximum center of diabatic heating is situated, strengthening the low-level cyclonic and high-level anticyclonic circulations. Further analyses indicate that the atmospheric heat source increased with fluctuations, with the maximum value appearing at noon and the strongest in the moving-out stage. Notably, the formation of TPV is related to the surface warming center driven by surface sensible heat, while its enhancement is mainly dependent on the latent heat of condensation. Furthermore, the main contributor to the latent heat is analyzed as a vertical transport of water vapor that promotes TPV development.