中文摘要：

纵贯的排水量和旋涡驱动的喷气的南方的摇摆广泛地作为观察的带平均数的带的风异例的可变性的主导的原因被接受(表示[u ]) 。在这研究，关于主要可变性的一个新想法观察[u ] 在中间的纬度，对流层被介绍。有主要可变性的二个不同的班，这被假设观察[u ] ：poleward 繁殖[u ]( 作为 PP 缩短了) 并且南方的摇摆。验证这个假设，一个点关联地图[u ] 在 200-hPa，在北方的寒冷期间，从 19572002 的每年的季节(NovemberApril ) 被用作一个标准。12 PP 年， PP 事件在可变性在是主导的[u ] ，并且 15 no_PP 年， PP 事件在是后退的和南方的摇摆在可变性是主导的[u ] ，被检验。结果证明可变性[u ] 在选择 PP 和 no_PP 年里是不同的。在 PP 年里， PP 事件统治可变性[u ] ；然而，南方的摇摆在 no_PP 年里是流行的。

英文摘要：

North-south displacements and meridional vacillations of the eddy-driven jet are widely accepted as the dominant cause of variability of the observational zonal-mean zonal wind anomalies （denoted [u]＇）. In this study, a new idea regarding the primary variability of the observational [u]＇ in the middle latitude troposphere is presented. It is hypothesized that there are two different classes of primary variability of the observational [u]＇： the poleward propagation of the [u]＇ （abbreviated as PP） and meridional vacillations. To validate this hypothesis, one-point correlation maps of [u]＇ at 200-hPa during the boreal cold season （November-April） of every year from 1957-2002 are used as a criterion. Twelve PP years, in which the PP events are dominant in the variability of [u]＇, and 15 no_PP years, in which the PP events are recessive and the meridional vacillations are dominant in the vari- ability of [u]＇, are examined. The results show that the variabilities of [u]＇ are different in the chosen PP and no_PP years. In the PP years, the PP events dominate the variability of [u]＇; however, the meridional vacillations are prevalent in the no_PP years.