青藏高原热力作用下的非绝热Rossby波  

DIABATIC ROSSBY WAVES UNDER THERMAL EFFECTS OF TIBETAN PLATEAU

作　　者：李黎明[1] 柏晶瑜[2] 黄锋 刘式适[1] 王彰贵 

机构地区：[1]北京大学物理学院,北京100871 [2]中国气象科学研究院,北京100081 [3]国家海洋局海洋环境预报研究中心,北京100081

出　　处：《应用气象学报》2002年第4期457-468,共12页Journal of Applied Meteorological Science

基　　金：国家重点基础研究项目G1 9980 4 0 90 0;G1 9990 4 380 9;国家攀登B项目TIPEX资助

摘　　要：从含非绝热项的准地转运动方程组出发 ,分析了青藏高原大尺度热力作用下非绝热Rossby波的一些性质 ,从理论上证明当背景西风气流为正压时 ,冬季高原冷却作用有利于Rossby波的经向传播 ,夏季高原大尺度热力作用不利于波动的经向传播。非绝热Rossby波的频率方程说明冬季高原的热力作用是中纬季节内振荡的重要激发机制。同时 ,在背景西风气流为纯斜压条件下 ,求解了高原热力作用下非绝热Rossby波的频率 ,并由频率方程说明冬季高原热力作用有利于波动向不稳定方向发展 ,而夏季高原的大尺度热力作用对波动稳定性的影响存在临界值。From diabatic quasi-geostrophic equations of motion, the characteristics of diabatic Rossby waves under the thermal effects of the Tibetan Plateau are analyzed. When the basic zonal flow is barotropic, it is demonstrated that the cooling of the Tibetan Plateau in winter not only facilitates the meridional propagation of Rossby waves, but also is an important driving mechanism of the intraseasonal oscillations in the middle and high latitudes. The large-scale heating of the Tibetan Plateau in summer prevents Rossby waves from propagating meridionally. When the basic zonal flow is baroclinic, it is found that the cooling of the Tibetan Plateau in winter facilitates the instability of Rossby waves, while there is a threshold in the influence of the heating of the Tibetan Plateau in summer on the stability of Rossby waves.

关 键 词：热力作用 非绝热Rossby波 准地转 青藏高原 经向传播 低频振荡 

分 类 号：P433[天文地球—大气科学及气象学]