用线性模式分析形成相当正压性的物理因子

AN ANALYSIS OF THE PHYSICAL FACTORS IN FORMING THE EQUIVALENT BAROTROPICITY WITH A LINEAR MODEL

中文关键词:  相当正压性  波数  热成风  β效应

英文关键词:Equivalent barotropicity  Wave number  Thermal wind  β-effect

中文摘要:

      用两层的线性准地转模式讨论了形成大气环流异常的相当正压性的物理因子。指出大气扰动的水平尺度、β效应和热成风,即平均西风在垂直方向上的梯度,是形成相当正压性的三个最主要的因子。另外还讨论了相当正压性所造成的对流层中层的流函数和厚度场的同相关系。最后指出了线性模式的缺陷。

英文摘要:

      In this paper, the physical factors related to the formation of the equivalent barotropicity of atmospheric circulation anomalies are studied using a two-layer linear quasi-geostrophical model. It is pointed out that the horizontal scales of disturbances, the β-effect and the thermal wind which is the vertical gradient of the mean westly wind are three major factors in maintaining the atmospheric equivalent barotropicity. The in-phase relationship between the stream function and the thickness field in the mid-troposphere resulted from the equivalent barotropicity is also discussed. At the end of this paper. the deficiencies of the linear model are pointed out.