Different ENSO teleconnections and their effects on the stratospheric polar vortex
Different ENSO teleconnections and their effects on the stratospheric polar vortex
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DOI：
10.1029/2008jd009920
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发表时间：
2008-09-30
影响因子：
4.4
通讯作者：
Hartmann, D. L.
中科院分区：
文献类型：
--
作者：
Garfinkel, C. I.;Hartmann, D. L.
再分析资料被用来研究厄尔尼诺南方涛动（ENSO）信号在对流层和平流层在晚秋至仲冬期间。与冷ENSO相比，温暖的ENSO事件具有对流层外的遥相关，增加了波1涡，减少了波2涡。波1的增加抵消了波2的减少，因此净效应是减弱的涡旋。冬季阿留申低压通过太平洋-北美型（PNA）加深引起对流层波强迫的这种修改。模式结果也被用来验证PNA是ENSO调制涡旋的主要机制。在东风准两年振荡（EQBO）期间，暖ENSO在观测记录中没有显示出PNA响应。因此，在EQBO条件下，极涡对ENSO的不同位相没有很强的响应，在WENSO条件下，极涡对QBO的不同位相也没有很强的响应。目前尚不清楚在EQBO期间缺乏PNA对温暖ENSO的反应是一个真实的物理现象还是我们有限的数据记录的一个特征。
Reanalysis data are used to study the El Nino-Southern Oscillation (ENSO) signal in the troposphere and stratosphere during the late fall to midwinter period. Warm ENSO events have extratropical tropospheric teleconnections that increase the wave 1 eddies and reduce the wave 2 eddies, as compared to cold ENSO. The increase in wave 1 overwhelms the decrease in wave 2, so the net effect is a weakened vortex. This modification in tropospheric wave forcing is induced by a deepening of the wintertime Aleutian low via the Pacific-North America pattern (PNA). Model results are also used to verify that the PNA is the primary mechanism through which ENSO modulates the vortex. During easterly Quasi-Biennial Oscillation (EQBO), warm ENSO does not show a PNA response in the observational record. Consequently, the polar vortex does not show a strong response to the different phases of ENSO under EQBO, nor to the different phases of QBO under WENSO. It is not clear whether the lack of a PNA response to warm ENSO during EQBO is a real physical phenomenon or a feature of the limited data record we have.