Journal article

Increased Quasi Stationarity and Persistence of Winter Ural Blocking and Eurasian Extreme Cold Events in Response to Arctic Warming. Part II: A Theoretical Explanation

Dehai Luo, Yao Yao, Aiguo Dai, Ian Simmonds, Linhao Zhong

JOURNAL OF CLIMATE | AMER METEOROLOGICAL SOC | Published : 2017

Abstract

In 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 ..

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Grants

Awarded by National Natural Science Foundation of China


Awarded by National Key Research and Development Program of China


Awarded by U.S.National Science Foundation


Awarded by U.S.Department of Energy's Office of Science


Awarded by U.S. National Oceanic and Atmospheric Administration


Awarded by Australian Research Council


Awarded by Directorate For Geosciences


Funding Acknowledgements

The first two authors acknowledge the support from the National Natural Science Foundation of China (Grants 41430533, 41375067, and 41505075) and the National Key Research and Development Program of China (2016YFA0601802).A.Dai is supported by the U.S.National Science Foundation (Grant AGS-1353740), U.S.Department of Energy's Office of Science (Award DE-SC0012602), and the U.S. National Oceanic and Atmospheric Administration (Award NA15OAR4310086).I.Simmonds was supported by Australian Research Council Grant DP 160101997.The authors thank three anonymous reviewers for their very valuable suggestions on the original submission.