热带基本气流对冬季北半球中高纬度准定常行星波的影响

INFLUENCE OF THE BASIC FLOW IN THE TROPICS ON STATIONARY PLANETARY WAVES AT MIDDLE AND HIGH LATITUDES DURING THE NORTHERN HEMISPHERE WINTER

中文摘要:

      本文利用一个包括Rayleigh摩擦、Newton冷却及水平涡旋热力扩散的准地转34层球坐标模式来研究冬季北半球地形与热源强迫所产生的准定常行星波与热带基本气流的关系。计算结果表明,冬季热带平流层基本气流是西风时,其北半球中高纬度平流层波数2准定常行星波的振幅偏大;而当冬季热带平流层基本气流是东风时,其北半球中高纬度平流层波数2准定常行星波的振幅偏小,这与实际结果比较一致。计算结果还表明冬季热带对流层基本气流对中高纬度准定常波的影响要比平流层基本气流的影响大。

英文摘要:

      The relationship between the quasi-stationary planetary waves forced by topography and heat source during the Northern Hemisphere is investigated by means of a quasi-geostrophic,34-level spherical model with Rayleigh frictipn,Newlonian cooling and the horizontal eddy thermal diffusivity.The computed results show that when the basic flow in the tropical stratosphere is the westerly,the amplitude of quasi-stationary,planetary wave for zonal wave number 2 at middle and high latitudes during the Northern Hemispheric winter is larger;while when the basic flow in the tropical stratosphere is the easterly,It is smaller.This is in agreements with the actual observed results.The compted results also show that influence of the basic flow in the tropical troposphere on the quasi-stationary planetary waves,is larger than that of the basic flow in the tropical stratosphere on the quasi-stationary planetary waves