非绝热加热对冷锋锋生过程影响的比较研究

Comparative Study of the Effects of Diabatic Heating on the Frontogenetical Process of the Cold Front

本文利用半地转模式研究了非绝热加热对冷锋锋生过程的影响。计算结果表明，非绝热加热包括大尺度凝结潜热、积云对流加热和感热都可以在加热区诱发出附加的锋生场。从而使加热区内的锋区强度得到明显加强；三种加热都能使上升速度增大，其中大尺度凝结潜热释放可在锋前出现一条宽约２００ｋｍ的强降水带．积云对流加热可使上升运动区范围缩小或在低层出现中尺度雨带，感热加热是产生中尺度雨带的一种可能机制。计算还表明，大尺度凝结潜热对锋生过程的影响最明显。它可以影响锋生过程中所有物理量。而积云对流加热和感热加热只对位温场和垂直速度场有明显影晌。但影响程度没有大尺度凝结潜热大。

A semigeostrophic model is used to study the effects of diabatic heating on thefrontogenetical process of the cold front. It is shown that the frontal strength inthe heating field is evidently strengthened by diabatic heating (including large-scalecondensational, cumulus and surface sensible heating). The upward motion of thefrontal zone is also enhanced by these three kinds of heating. The large-scale condensetional heating produces a severe rainband whose scale is about 200km in thewarm sector of the front. Cumulus heating decreases the horizontal scale of upwardmotion and produces multiple mesoscale rainbands in the lower atmosphere. Surfacesensible heatig is a possible mechanism of the formation of multiple mesoscale rainbands. The calculating results also show that large-scale condensational beating ismore effective than cumulus and surface sensible heating for frontogenesis and caninfluence all physical quantities in, the frontogenetical process. Cumulus and surfacesensible heating *Pan only affect the fields of potential temperature and verticalvelocity.