Increased Quasi Stationarity and Persistence of Winter Ural Blocking and Eurasian Extreme Cold Events in Response to Arctic Warming. Part II: A Theoretical Explanation
Increased Quasi Stationarity and Persistence of Winter Ural Blocking and Eurasian Extreme Cold Events in Response to Arctic Warming. Part II: A Theoretical Explanation
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冬季乌拉尔阻塞和欧亚极冷事件响应北极变暖的准平稳性和持续性增加。
DOI：
10.1175/jcli-d-16-0262.1
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发表时间：
2017-04
期刊：
影响因子：
--
通讯作者：
L. Zhong
中科院分区：
文献类型：
--
作者：
D. Luo;Y. Yao;A. Dai;I. Simmonds;L. Zhong
本文的第一部分指出，与北极变暖有关的欧亚冷异常强烈地依赖于乌拉尔阻塞（UB）的准平稳性和持续性。分析表明，在弱平均西风和垂直切变（准正压）、弱天气尺度涡旋和大的行星波异常条件下，UB的增长缓慢，振幅较小。在这种情况下，可以看到一个准静态和持久的UB。在强MWW和VS（准斜压）条件下，天气尺度涡旋较强，UB发展较快，UB持续性较差，振幅较大。在这种情况下，观察到一个显着的倒退的UB. UB的运动和持久性依赖于背景条件背后的动力学机制进一步研究使用非线性多尺度模式。结果表明，在准斜压条件下，当阻塞具有较大振幅时，阻塞的发生与阻塞的强度有关。
AbstractIn Part I of this study, it was shown that the Eurasian cold anomalies related to Arctic warming depend strongly on the quasi stationarity and persistence of the Ural blocking (UB). The analysis here revealed that under weak mean westerly wind (MWW) and vertical shear (VS) (quasi barotropic) conditions with weak synoptic-scale eddies and a large planetary wave anomaly, the growth of UB is slow and its amplitude is small. For this case, a quasi-stationary and persistent UB is seen. However, under strong MWW and VS (quasi baroclinic) conditions, synoptic-scale eddies are stronger and the growth of UB is rapid; the resulting UB is less persistent and has large amplitude. In this case, a marked retrogression of the UB is observed.The dynamical mechanism behind the dependence of the movement and persistence of UB upon the background conditions is further examined using a nonlinear multiscale model. The results show that when the blocking has large amplitude under quasi-baroclinic conditions, the blocki...
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影响因子：
3.1
作者：
D. Luo
通讯作者：
D. Luo
影响因子：
3.1
作者：
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通讯作者：
Hock Lim;Chih-Pei Chang
DOI：
10.1073/pnas.1304867110
发表时间：
2013-05
期刊：
Proceedings of the National Academy of Sciences
影响因子：
--
作者：
J. Screen;I. Simmonds
通讯作者：
J. Screen;I. Simmonds
影响因子：
4.9
作者：
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通讯作者：
Vihma, Timo
影响因子：
8.9
作者：
K. Haines;A. J. Holland
通讯作者：
K. Haines;A. J. Holland