高低空急流与水汽凝结过程对暖锋环流演变的影响

INFLUENCES OF UPPER AND LOW-LEVEL JETS AND CONDENSATION PROCESS OF MOISTURE ON EVOLUTION OF WARM FRONT CIRCULATION

中文关键词:  高低空急流  凝结  暖锋

英文关键词:Upper-lower jet  Condensation  Warm front

中文摘要:

      利用包括水汽凝结过程的原始方程模式模拟了高空西风急流和低空南风急流中暖锋环流的演变以及凝结的发生。计算结果显示,水汽凝结过程对暖锋环流有非常重大的作用,是暖锋锋区产生强中尺度深对流的重要机制。与干模式大气中高空西风急流对暖锋环流的影响远大于低空南风急流的结论相反,在含有水汽凝结过程的湿大气中,低空南风急流的作用远大于高空西风急流,它是暖锋锋区中产生强中尺度降水的更重要因子;高低空急流的共同作用,对湿暖锋锋区中多重中尺度雨带的形成具有重要作用。

英文摘要:

      The evolution of warm front circulation and occurrence of condensation in the upper level westerly jet and low-level southerly jet are simulated by using a primitive equation mode1 including moisture condensation process.The calculation results show that the moisture condensation plays a very significant role on warm front circulation and may be an important mechanism to excite strong mesoscale deep convection in the warm frontal zone.In the moist atmospheric model with moisture condensation process the effects of low-level southerly jet on the warm front circulation are much larger than the upper-level westerly jet and are more important factors for exciting strong mesoscale precipitation in the warm frontal zone while in the dry case,as opposed to the moist case,the influences of upper-level westerly jet on the warm frontal circulation are much larger than the low-level southerly jet.A combination of the upper and low-level jets has important effects on formation of multiple mesoscale frontal rainbands in the moist warm frontal zone.