大暴雨过程中与急流相关气块的三维运动分析

用４８ｈ三维轨迹分析和物理量诊断分析相结合的方法研究了１９９１年７月上旬的一次大暴雨过程及其与高低空急流的联系。结果表明，暴雨区高空的气块来自高空急流的入口区，并穿过急流中心到达急流的出口区。雨区上空的辐散和２００ｈＰａ高空急流出口区气块的减速运动相联系。低层的暖湿空气来自于ＳＳＷ气流，并在低空急流中心的前方辐合上升。高空辐散所引起的低层减压使低空急流加强和低层暖湿空气的加速运动。

3-D TRAJECTORY ANALYSIS OF AIR PARCEL ASSOCIATED WITH HIGH AND LOW LEVEL JETS IN HEAVY RAIN

A case of heavy rain in July 1991 was diagnosed with 48-hour three dimensional trajectory of air parcel associated with the high and low level jets. The high level air parcel over the rainfall area is coming from the entrance of high level jet and passing the core of the jet to the exit region. The high level divergence over the rainfall area is related to the deceleration of air motion. The low level warm and moist air is coming from the SSW current,which is convergence and asscending at the front of the core of low level jet. The acceleration of low level air and the intensification of low level jet are associated with the high level divergence due to the reduction of low level pressure.