On the Semiannual Variation in the Northern Hemisphere Extratropical Height Field
On the Semiannual Variation in the Northern Hemisphere Extratropical Height Field
复制标题
北半球温带高度场的半年变化
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
Tsing‐Chang Chen
中科院分区：
文献类型：
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作者：
C. Wikle;Tsing‐Chang Chen
对北半球温带500 hpa高度场最大半年振荡（SAO）振幅的空间分布进行了定性分析，表明SAO具有非常明显的纬向不对称东西向结构。NH静止涡旋和NH SAO的比较表明，NH中纬度SAO几乎完全可以解释为静止涡旋年变化的时空不对称性的结果。西伯利亚和阿拉斯加的极海SAO极大值与东西方向的静止涡旋分布有关。这表明，最终，北半球温带的SAO机制仅仅是陆海对比的结果，类似于van Loon提出的南半球（SH）温带SAO的机制。然而，主要的区别在于，由于北半球大陆块较大，北半球温带以东西陆海对比为主，而北半球温带以东西向陆海对比为主。
Abstract A qualitative examination of the spatial distribution of the maximum semiannual oscillation (SAO) amplitudes in the Northern Hemisphere (NH) extratropical 500-hPa height field suggests that the SAO has a very dominant zonally asymmetric east-west structure. A comparison between the NH stationary eddies and the NH SAO shows that the NH midlatitude SAO can be explained almost entirely as being a result of the spatial and temporal asymmetries in the annual variation of the stationary eddies. It is also shown that the polar sea SAO maxima over Siberia and Alaska are related to the east-west stationary eddy distribution. It is suggested that, ultimately, the mechanism for the SAO in the NH extratropics is simply a result of land-sea contrasts, similar to the mechanism proposed by van Loon for the Southern Hemisphere (SH) extratropical SAO. The chief difference, however, is that the NH extratropics are dominated by east-west land-sea contrasts due to the larger continental land masses in the NH, while ...