Northern Hemisphere winter atmospheric teleconnections are intensified by extratropical ocean-atmosphere coupling
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- Mori, Masato
- Research Institute for Applied Mechanics, Kyushu University
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- Kosaka, Yu
- Research Center for Advanced Science and Technology, The University of Tokyo
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- Taguchi, Bunmei
- Faculty of Sustainable Design, University of Toyama
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- Tokinaga, Hiroki
- Research Institute for Applied Mechanics, Kyushu University
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- Tatebe, Hiroaki
- Japan Agency for Marine-Earth Science and Technology
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- Nakamura, Hisashi
- Research Center for Advanced Science and Technology, The University of Tokyo
Description
The role of extratropical atmosphere-ocean coupling in generating and maintaining large-scale atmospheric low-frequency variability remains an open question owing to vigorous atmospheric internal fluctuations. Here, we use coupled and uncoupled large-ensemble global model simulations to clarify how the coupling intensifies atmospheric teleconnection patterns in the Northern Hemisphere winter.Weshowthat the extratropical coupling selectively enhances the variance of three principal modes of variability, explaining 13%, 11%, and 10% of the total variance of Pacific/North American, North Atlantic Oscillation, and Warm-Arctic Cold-Eurasian patterns, respectively. Atmosphere-ocean coupling reduces damping to lower-tropospheric available potential energy, which in turn increases kinetic energy by changing energy transfer within the mode. The extratropical ocean is overall passive (adjustable) to large-scale atmospheric variation, thus contributing to the prominence of these modes. The geographical dependence of available potential energy damping suggests the existence of mode-specific sweet spots where the influence of coupling operates efficiently, providing a clue to improving the model biases in variance and signal-to-noise ratio of these modes.
Journal
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- Communications Earth & Environment
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Communications Earth & Environment 124 (5), 1-16, 2024-03-01
Springer Nature
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Keywords
Details 詳細情報について
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- CRID
- 1050300446003799424
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- ISSN
- 26624435
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- HANDLE
- 2324/7178881
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- Text Lang
- en
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- Article Type
- journal article
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- Data Source
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- IRDB
- Crossref
- KAKEN
- OpenAIRE