The Global Teleconnection Signature of the Madden‐Julian Oscillation and Its Modulation by the Quasi‐Biennial Oscillation
The Global Teleconnection Signature of the Madden‐Julian Oscillation and Its Modulation by the Quasi‐Biennial Oscillation
复制标题
马登朱利安振荡的全球遥相关特征及其准两年振荡的调制
DOI：
10.1029/2020jd032653
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
S. C. Heever
中科院分区：
文献类型：
--
作者：
B. Toms;E. Barnes;E. Maloney;S. C. Heever
最近的研究表明，马登-朱利安振荡（MJO）的热带和热带外特征取决于平流层准两年振荡（QBO）的状态。考虑到这一点，我们使用再分析和全球气候模式（CESM 2-WACCM）来分析与MJO相关的对流层上部-平流层下部位势高度异常的全球特征，并量化这些遥相关对QBO状态的依赖性。我们发现，全球遥相关签名的MJO依赖于QBO的状态。在全球范围内，在再分析中，与MJO相关的20至90天250 hPa高度场方差的比例在北方冬季和夏季的东风QBO阶段最大，在北方冬季的西风QBO阶段最小。QBO相位之间的差异主要是由MJO的热带签名的变化，虽然在北方冬季的北方半球的遥相关是特别突出的东风QBO阶段。另外，赤道外MJO遥相关的QBO调制主要是通过遥相关位置的变化来实现的。QBO-MJO关系在CESM 2-WACCM中也很明显，但比观察到的要弱。这种大气外调制意味着，受益于增加的亚季节的可预测性，由于MJO的地区也可能会改变作为QBO的函数。从更广泛的意义上说，这些发现强调，知识的热带平流层状态，特别是因为它涉及到QBO，是重要的了解之间的联系MJO和热带外。
Recent research has suggested that the tropical and extratropical character of the Madden‐Julian oscillation (MJO) depends on the state of the stratospheric quasi‐biennial oscillation (QBO). With this in mind, we use both reanalysis and a global climate model (CESM2‐WACCM) to analyze the global character of upper tropospheric‐lower stratospheric geopotential height anomalies connected with the MJO and quantify dependencies of these teleconnections on the state of the QBO. We find that the global teleconnection signature of the MJO depends upon the state of the QBO. Globally, within reanalysis the fraction of 20‐ to 90‐day 250‐hPa geopotential height variance linked to the MJO is largest during boreal winter and summer for easterly QBO phases and smallest during westerly QBO phases of boreal winter. The difference between QBO phases is mostly driven by changes in the tropical signature of the MJO, although during boreal winter the Northern Hemispheric teleconnections are particularly more prominent during easterly QBO phases. Otherwise, the QBO modulation of extratropical MJO teleconnections is mainly realized through changes in the locations of the teleconnections. A QBO‐MJO relationship is also apparent within CESM2‐WACCM but is weaker than that observed. This extratropical modulation implies that the regions that benefit from increased subseasonal predictability due to the MJO may also change as a function of the QBO. In a broader sense, these findings emphasize that knowledge of the tropical stratospheric state, particularly as it relates to the QBO, is important for understanding the connections between the MJO and the extratropics.
马登朱利安涛动对厄尔尼诺南方涛动期间高纬度冬季阻塞的影响
影响因子：
4.9
作者：
Henderson, Stephanie A.;Maloney, Eric D.
通讯作者：
Maloney, Eric D.
影响因子：
6.8
作者：
Lauritzen, P. H.;Nair, R. D.;Tribbia, J. J.
通讯作者：
Tribbia, J. J.