高低空位涡扰动、非绝热加热与气旋的发生发展

GENESIS AND DEVELOPMENT OF CYCLONE WITH UPPER/LOWER POTENTIAL VORTICITY(PV) ANOMALY、DIABATIC HEATING

关键词:  低层位涡扰动  位涡扰动柱  最大加热层

Key words:  low-level PV anomaly  PV anomaly column  maximum heating level

摘要:

从湿位涡的扰动量出发,来分析气旋发展过程中高低空位涡的变化,结果表明:低层位涡扰动先于气旋并孤立于高层位涡扰动而存在,在气旋发生过程中,低层正值位涡扰动发展上伸,与高层下传的位涡相接,形成一条正值位涡扰动柱,而湿位涡扰动柱的形成正是气旋发生的重要标志。江南暴雨期的非绝热加热主要由降水产生的凝结潜热造成,最大加热层的出现,是低层位涡扰动产生和向上发展的一个重要原因,对气旋的发展起着促进作用。

Abstract:

The character of upper/lower PV are analyzed based on PV anomaly with the genesis and development of cyclone, with results that low-level PV anomaly (LPVA), which is isolated from upper PV anomaly and has a leading/simultaneous current relative to cyclone, will grow upward, join with upper level downward PV anomaly, form PV anomaly column (PVAC) under available conditions. Thus the conclusion is obtains that the forming of PVAC is a remarkable symbol of cyclogenesis. Further study shows that diabetic heating during a torrential rain period in the South of Changjiang River is mainly produced by condensation latent heat from precipitation and the appearance of maximum heating level brings an increased PV beneath it, which, accelerating the development of the cyclone, is another important cause of rising and developing of LPVA.