地面暖带附近锋生的数值试验

NUMERICAL EXPERIMENT ON FRONTOGENESIS NEAR WARM BUMP

采用半地转方程的二维锋生模式，研究了地面暖带附近锋生过程中，大尺度斜压区、地面暖带和潜热释放之间的相互作用。结果表明：变形场中的孤立暖带，当它位于大尺度斜压区暖空气一侧时．可在有限时间内形成强锋区（有潜热加热时锋生速度更快）；当暖带与大尺度斜压区配合时，可出现双锋区结构，强锋区可能先在暖带中出现。在暖带深厚并有潜热释放时表现更明显且有利于双锋区结构的维持。锋生强迫作用和位温扰动是梅雨锋附近两条中－α尺度雨带形成的可能机制。

Investigated by a two-dimensional semi-geostrophic equation frontogenesis model arethe front generation near a warm bump and the interactions among a large scale baroclinic zone,a warm bump and latent heat release,Results show that,when、a isolated warm bump in the de-formation field lies on the warm-air side of the baroclinic zone,a strong frontal zone will emergewithin a limited time;frontogenisis will be speeded up with latent beating available;if a largescalebaroclinic zone coexists with the warm bump,a bi-frontal structure will come into being,whichwill、be maintained if latent heat release continues;the strong frontal zone might appear forst in the bump.especially when the latter is deep and provided with released latent heat The frontogeneticforcing and potential temperature perturbation represent possible mechanisms for the formation ofthe two meso-α scale rainbands near the Meiyn front.