DOI: 10.1002/2014GL062210
论文题名: Quantifying barotropic and baroclinic eddy feedbacks in the persistence of the Southern Annular Mode
作者: Nie Y. ; Zhang Y. ; Chen G. ; Yang X.-Q. ; Burrows D.A.
刊名: Geophysical Research Letters
ISSN: 0094-9525
EISSN: 1944-9256
出版年: 2014
卷: 41, 期: 23 起始页码: 8636
结束页码: 8644
语种: 英语
英文关键词: barotropic/baroclinic eddy feedback
; eddy-mean flow interactions
; finite amplitude wave activity diagnostic
; SAM
Scopus关键词: Mechanical waves
; Mixing
; Wave propagation
; Barotropic
; Eddy-mean flow interaction
; Effective diffusivities
; Eulerian-lagrangian
; Finite amplitude waves
; Potential vorticity mixing
; SAM
; Southern Annular Mode
; Feedback
; baroclinic wave
; barotropic wave
; diffusivity
; Lagrangian analysis
; persistence
; vorticity
; wave action
; wave propagation
; zonal flow
英文摘要: Understanding the persistence of the Southern Annular Mode (SAM) is important for the intraseasonal and decadal predictability of SAM. Using the ERA-40 and ERA-Interim reanalysis data, this study introduces a new method to quantify the relative roles of barotropic and baroclinic eddy feedbacks in the SAM persistence. Through a hybrid Eulerian-Lagrangian Finite Amplitude Wave Activity diagnostic, it is found that (i) transient wave activity is important in driving the SAM, but it provides a negative feedback to the SAM persistence. (ii) Irreversible potential vorticity mixing, through barotropic processes in the upper troposphere, plays an important role in driving and sustaining the SAM variability. Particularly, following the poleward shift of the eddy-driven jet, the reduction/enhancement in effective diffusivity on the jet's poleward/equatorward flank can be understood by a stronger/weaker zonal jet acting as a robust/leaky mixing barrier. (iii) Baroclinic eddy generation and vertical wave propagation mainly act to sustain the SAM variability. Key PointsA new method quantifying baroclinic/barotropic eddy feedback in SAM introducedBarotropic processes drive and sustain SAM; baroclinic ones extend SAM persistenceWave activity drives SAM variability but feedbacks negatively for SAM persistence ©2014. The Authors. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921597344&doi=10.1002%2f2014GL062210&partnerID=40&md5=40e8ad73563d482e43c261bcb4fa2d16
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6789
Appears in Collections: 气候减缓与适应
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作者单位: Institute for Climate and Global Change Research, School of Atmospheric Sciences, Nanjing University, Nanjing, China
Recommended Citation:
Nie Y.,Zhang Y.,Chen G.,et al. Quantifying barotropic and baroclinic eddy feedbacks in the persistence of the Southern Annular Mode[J]. Geophysical Research Letters,2014-01-01,41(23).