非均匀饱和广义湿位涡在暴雨分析与预测中的应用

Application of Generalized Moist Potential Vorticity in Non-uniformly Saturated Atmosphere to Torrential Rain Forecast

考虑实际大气非均匀饱和特性,通过引入广义位温及广义湿位涡方程,对华北暴雨和江淮梅雨锋暴雨的发生及落区进行了广义湿位涡异常的诊断分析,表明暴雨形成时大气低层有广义湿位涡的异常出现。对广义湿位涡倾向的计算表明:它对暴雨的发生有一定指示作用,因而可利用广义湿位涡的异常来识别暴雨的出现。

The introduction of generalized potential temperature and tendency equation of generalized moist potential vorticity into the thermodynamic framework is based on the non-uniform saturation of real atmosphere. The generalized moist potential vorticity （GMPV） equation is deduced by absorbing the generalized potential temperature. The water vapor and its gradient effect can be manifested in the GMPV equation, which indicates the convergence mechanism of water vapor at lower levels when torrential rain occurs. The GMPV anomaly is used in diagnostic studies of torrential rain both in North China and Yangtze River Basin. The results show that dynamic identification and forecasting of torrential rain from the perspective of generalized moist potential vorticity and its anomaly are effective, which maybe provide a new thought for the operational application of the GMPV.