大气层结和中尺度位温扰动对锋区多重垂直运动带形成的影响  

THE INFLUENCES OF STRATIFICATION AND MESOSCALE POTENTIAL TEMPERATURE DISTURBANCES ON THE FORMATION OF MULTIPLE BAND OF VERTICAL MOTION IN THE FRONTOGENESIS AREA

作　　者：吕克利[1] H.R.Cho 

机构地区：[1]南京大学大气科学系 [2]加拿大多伦多大学物理系

出　　处：《气象学报》1991年第3期278-287,共10页Acta Meteorologica Sinica

摘　　要：文中利用半地转锋生模式讨论了大气层结,天气尺度位温场和中尺度位温扰动对锋区多重垂直运动带形成的影响,给出了垂直运动场的演变图。结果显示,大气层结和中尺度位温扰动对锋区垂直运动带的形成有重要影响,在合适的大气层结下,垂直伸展较高的低空中尺度位温扰动是形成锋前暖区多重雨带的可能驱动机制之一;不同高度上的中尺度位温扰动以低层扰动影响最大,中层次之;天气尺度位温扰动场的水平温差对锋生速度和锋区垂直运动带都有重要影响;中尺度位温扰动对锋生速度没有什么作用。A frontogenesis model is studied, which includes three kinds of stratification profiles and synoptic-scale potential temperature field with different amplitudes, as well as mesoscale potential temperature disturbances fields placed at different heights. The time changes of vertical motion field are shown. The results show that atmospheric stratification and mesoscale potential temperature disturbances play important roles in the formation of multiple band of vertical motion. The mesoscale disturbance which has considerable vertical extent and is located at lower-level has the most important influence, and may be a possible mechanism triggering the formation of multiple rainbands in the warm-sector ahead of the cold front if the stratification is suitable, and that located at upper-level is unimportant. The amplitude of synoptic-scale potential temperature field is of great importance to the speed of frontogenesis and vertical motion field, but the effect of mesoscale disturbance on the speed of frontogenesis is very little.

关 键 词：大气 层结 中尺度 位温 锋区 运动 

分 类 号：P434.5[天文地球—大气科学及气象学]