夏季江淮气旋的准地转诊断分析

本文通过实例计算,讨论了包含潜热的淮地转ω方程在夏季江淮气旋活动及梅雨暴雨预报中的适用性,并分析了绝热因子和非绝热因子的贡献。主要结论有:(1)上述方程可以较准确地确定上升、下沉区及其主要中心的位置;(2)垂直运动的符号基本上可由绝热因子确定,潜热加热对上升运动起增辐作用;(3)稳定性降水对地面低压中心的生成起主要作用;(4)可以通过计算500hPa Q矢量散度来预报降水区、暴雨区及气旋波活动的位置。

A QUASI-GEOSTROPHIC DIAGNOSIS OF THE SUMMER CYCLONES OVBR THE CHANGJIANG-HUAIHE VALLEY

In this paper the quasi-geostrophic omega equation involvingcondensational heating is solved to discuss its aplicabilitv to summercyclones over the Changjiang-Huaihe Valley. The contributions of theadiabatic and diabatic processes arealso analysed. The following conclu-sions are thus deduced: (1) The equation can accurately determinethe ascending and descending regions and the locations of their maincentres; (2) The direction of the vertical motion is generally decidedby the adiabatic process while the condensational heating amplifies theupward velocity; (3) Stable precipitation is more important than convec-tion to the formation of the surface depression; (4) Calculation of500-hPa Q divergence can be used to predict the rain belt, area ofheavy rain and the most possible location of cyclogenesis.