广西一次暴雨过程中准静止中尺度涡旋的位涡反演诊断

Potential vorticity inversion and diagnosis of quasi-stationary mesoscale vortex in a rainstorm process in Guangxi

利用分片位涡反演方法,对影响2008年6月广西一次暴雨过程的准静止中尺度低涡(简称"广西涡")进行反演计算,诊断分析不同物理性质的位涡扰动对广西涡的贡献。结果表明:与潜热释放有关的湿的位涡扰动(Qh)对广西涡有直接作用,并对广西涡发展有主要正贡献,其影响主要集中在对流层中低层;与潜热释放无关的干位涡扰动(Qd)对广西涡的贡献集中在对流层中高层,有利于广西涡向高层扩展和加深;Qh和Qd均对广西涡路径有影响。

In this paper, piecewise potential vortieity （PV） inversion method is used to carry out inversion on the quasi-stationary mesoscale vortex （hereinafter called Guangxi vortex） in the process of Guangxi flashflood rainstorm in June 2006, and contributions of various PV pertur- bations with different physical properties on the Guangxi vortex are diagnostically analyzed. The results show that the wet PV perturbation Qhrelated to latent heat release had direct effect on the Guangxi vortex and it played as the major positive contribution on the development of the vortex. Its contribution was concentrated on low-to-mid troposphere. While the contribution of dry PV perturbation Qh, no relation with la- tent release, was mainly concentrated on mid-to-high troposphere. It was favorable for the Guangxi vortex to extend to high level and deepen. Both Qh and Q~ had influence on the tracks of the vortex.