| DOI: | 10.1007/s00382-017-3771-1
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| Scopus记录号: | 2-s2.0-85021182442
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| 论文题名: | Understanding Rossby wave trains forced by the Indian Ocean Dipole |
| 作者: | McIntosh P.C.; Hendon H.H.
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| 刊名: | Climate Dynamics
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| ISSN: | 9307575
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| 出版年: | 2018
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| 卷: | 50, 期:2018-07-08 | | 起始页码: | 2783
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| 结束页码: | 2798
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| 语种: | 英语
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| Scopus关键词: | convective system
; El Nino-Southern Oscillation
; Indian Ocean Dipole
; jet flow
; Rossby wave
; Southern Hemisphere
; storm track
; vorticity
; wave dispersion
; wave force
; wave propagation
; wave reflection
; Australia
; Indian Ocean
; Indian Ocean (East)
; Pacific Ocean
; Pacific Ocean (West)
; Southern Ocean
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| 英文摘要: | Convective variations over the tropical Indian Ocean associated with ENSO and the Indian Ocean Dipole force a Rossby wave train that appears to emanate poleward and eastward to the south of Australia and which causes climate variations across southern Australia and more generally throughout the Southern Hemisphere extratropics. However, during austral winter, the subtropical jet that extends from the eastern Indian Ocean into the western Pacific at Australian latitudes should effectively prohibit continuous propagation of a stationary Rossby wave from the tropics into the extratropics because the meridional gradient of mean absolute vorticity goes to zero on its poleward flank. The observed wave train indeed exhibits strong convergence of wave activity flux upon encountering this region of vanishing vorticity gradient and with some indication of reflection back into the tropics, indicating the continuous propagation of the stationary Rossby wave train from low to high latitudes is inhibited across the south of Australia. However, another Rossby wave train appears to emanate upstream of Australia on the poleward side of the subtropical jet and propagates eastward along the waveguide of the eddy-driven (sub-polar) jet into the Pacific sector of the Southern Ocean. This combination of evanescent wave train from the tropics and eastward propagating wave train emanating from higher latitudes upstream of Australia gives the appearance of a continuous Rossby wave train propagating from the tropical Indian Ocean into higher southern latitudes. The extratropical Rossby wave source on the poleward side of the subtropical jet stems from induced changes in transient eddy activity in the main storm track of the Southern Hemisphere. During austral spring, when the subtropical jet weakens, the Rossby wave train emanating from Indian Ocean convection is explained more traditionally by direct dispersion from divergence forcing at low latitudes. © 2017, Springer-Verlag GmbH Germany. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/109348
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| Appears in Collections: | 影响、适应和脆弱性
气候变化事实与影响
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作者单位: | CSIRO, GPO Box 1538, Hobart, 7001, Australia; Bureau of Meteorology, GPO Box 1289, Melbourne, 3001, Australia
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| Recommended Citation: | |
McIntosh P.C.,Hendon H.H.. Understanding Rossby wave trains forced by the Indian Ocean Dipole[J]. Climate Dynamics,2018-01-01,50(2018-07-08)
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