全球500kPa角动量与EP通量的季节变化

ON THE SEASONAL TRANSITION IN GLOBAL ANGULAR MOMENTUM AND EP-FLUX AT 500HPA

中文关键词:  角动量  EP通量  季节变化

英文关键词:Angular momentum  EP-flux  Seasonal transition

中文摘要:

      利用ECMWF提供的9a(198O-1988)资料,从定性和定量角度分析500hPa全球东西风带的角动量和EP通量的季节过渡。结果发现:不仅角动量存在明显的季节性急变,而且反映波活动的EP通量也存在相应的季节性急变。另外,季节性急变的发生时间在东西风带亦有所不同。

英文摘要:

      Utilizing the daily data set from ECMWF for nine years of 1980一1988, the seasonal transition of angular momentum and EP-flux for the easterlies and westerlies in Northern and Southern Hemispheres are analyzed by qualtitative and quantitative means. The follow- ing results are found:(1) In the westerlies, there are remarkable seasonal rapid changes happened generally in April and in October. and this phenomenon in Northern Hemisphere is more obvious than that in Southern Hemisphere.(2) In the easterlies, there is a sudden change occuring in June over Northern Hemi-sphere, yet over Southern Hemisphere the seasonal transition of the easterlies is not obvious.On the basis of this evidence the difference of factors affecting the rapid changes of April and June is discussed.