DOI: 10.1175/JCLI-D-12-00303.1
Scopus记录号: 2-s2.0-84881640451
论文题名: The role of SST structure in convectively coupled kelvin-rossby waves and its implications for MJO formation
作者: Kang I.-S. ; Liu F. ; Ahn M.-S. ; Yang Y.-M. ; Wang B.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2013
卷: 26, 期: 16 起始页码: 5915
结束页码: 5930
语种: 英语
Scopus关键词: Dominant time scale
; General circulation model
; Intraseasonal disturbances
; Madden-Julian oscillation
; Moisture convergence
; Planetary boundary layers
; Propagation characteristics
; Surface boundary conditions
; Atmospheric thermodynamics
; Boundary conditions
; Climatology
; Friction
; Moisture
; atmosphere-ocean coupling
; atmospheric general circulation model
; baroclinic motion
; boundary condition
; boundary layer
; convergence
; Kelvin wave
; Madden-Julian oscillation
; moisture flux
; oceanic general circulation model
; Rossby wave
; sea surface temperature
英文摘要: The dynamics of the Madden-Julian oscillation (MJO) are investigated using an aqua-planet general circulation model (GCM) and a simple one-and-a-half-layer model with a first-baroclinic mode and a planetary boundary layer. The aqua-planet GCM with zonally symmetric SST conditions simulates tropical intraseasonal disturbances with a dominant time scale of about 20 days, which is much faster than that of the observed MJO, although the GCM with realistic surface boundary conditions is shown to reproduce the observed MJO reasonably well. The SST with a broader meridional structure slows down the propagation speed. Several experiments done with various zonally symmetric surface boundary conditions showed that the meridional structure of the SST in fact is a control factor for the propagation characteristics of the MJO. With a simple theoretical model for the MJO, it is shown that the instability of the moist coupled Kelvin-Rossby waves depends on the SST structure, which determines the lower-level moisture field. The SST with a narrow meridional structure prefers to enhance only the fast eastward Kelvin wave, while the broader SST provides enough off-equatorial moisture for the growth of the Rossby component, which couples strongly with the Kelvin component and slows down the eastward modes. The SST influences the coupled Kelvin-Rossby waves through changes in the moist static stability of the free atmosphere and the frictional moisture convergence in the planetary boundary layer. The present results suggest that the essential dynamics of the MJO are rooted in a convectively coupled Kelvin-Rossby wave packet with frictional moisture convergenc. © 2013 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51743
Appears in Collections: 气候变化事实与影响
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作者单位: School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea; Department of Meteorology and International Pacific Research Center, University of Hawai'iat Manoa, Honolulu, HI, United States; Computational Science and Technology, Seoul National University, Seoul, South Korea
Recommended Citation:
Kang I.-S.,Liu F.,Ahn M.-S.,et al. The role of SST structure in convectively coupled kelvin-rossby waves and its implications for MJO formation[J]. Journal of Climate,2013-01-01,26(16)