【摘要】 利用原始方程模式探讨了高空西风急流和低空南风急流中锢囚锋环流的演变和增强机制。数值结果显示 ,在干大气中 ,高空西风急流的存在使锢囚锋非地转环流和锋区上升速度迅速变化、增强 ,并有利于重力内波的垂直传播 ;低空南风急流对锋区环流型的变化影响较大 ,但环流较为平直 ,对锋区上升速度的增强作用不大 ,产生的锋区上升速度比高空西风急流中小得多 ;高低空急流的同时存在 ,对锢囚锋环流的作用比较复杂 ,其影响比高低空急流各自作用的叠加要大。更多还原

【Abstract】 The evolution and enhancement of occluded frontal circulation in upper level westerly jet and lower level southerly jet are discussed by using a dry primitive equation model. The numerical results show that the upper level jet intensifies greatly the occluded frontal circulation and vertical velocity in frontal zone, and it is advantageous to propagate vertically internal gravity waves excited in frontal zone. The calculations also show that the effects of lower level southerly jet on occluded front are much smaller than upper level jet, and it causes smaller enhancement of upward velocity and smooth frontal circulation. The combination of upper and lower level jets has more complex influences on occluded frontal circulation.更多还原