DOI: 10.1002/2013GL058187
论文题名: Realistic initiation and dynamics of the Madden-Julian Oscillation in a coarse resolution aquaplanet GCM
作者: Ajayamohan R.S. ; Khouider B. ; Majda A.J.
刊名: Geophysical Research Letters
ISSN: 0094-8329
EISSN: 1944-8060
出版年: 2013
卷: 40, 期: 23 起始页码: 6252
结束页码: 6257
语种: 英语
英文关键词: GCM
; MJO
Scopus关键词: GCM
; Global climate model
; Initiation and propagation
; Initiation mechanism
; Madden-Julian oscillation
; MJO
; Model parameterization
; Sea surface temperatures
; Climatology
; Flow patterns
; Lakes
; Dynamics
; air-sea interaction
; climate modeling
; flow pattern
; general circulation model
; Madden-Julian oscillation
; numerical model
; resolution
; Rossby wave
; sea surface temperature
; wave propagation
; Pacific Ocean
; Pacific Ocean (West)
英文摘要: The main mechanisms for the initiation and propagation of the Madden-Julian Oscillation (MJO) are still widely debated. The capacity of operational global climate models (GCMs) to correctly simulate the MJO is hindered by the inadequacy of the underlying cumulus parameterizations. Here we show that a coarse resolution GCM, coupled to a simple multicloud model parameterization mimicking the observed dynamics and physical structure of organized tropical convection, simulates the MJO in an idealized setting of an aquaplanet without ocean dynamics. We impose a fixed nonhomogeneous sea-surface temperature replicating the Indian Ocean/Western Pacific warm pool. This results in a succession of MJOs with realistic phase speed, amplitude, and physical structure. Each MJO event is initiated at a somewhat random location over the warm pool and dies sometimes near the eastern boundary of the warm pool and sometimes at a random location way beyond the warm pool. Also occasionally the MJO events stall at the center of maximum heating. This is reminiscent of the fact that in nature some MJOs stall over the maritime continent while others reach the central Pacific Ocean and beyond. The initiation mechanism in the model is believed to be a combination of persistent intermittent convective events interacting with observed large-scale flow patterns and internal tropical dynamics. The large-scale flow patterns are associated with planetary-scale dry Kelvin waves that are triggered by preceding MJO events and circle the globe, while congestus cloud decks on the flanks of the warm pool are believed to force Rossby gyres which then funnel moisture toward the equatorial region. Key Points Realistic MJO initiation and dynamics in a GCM Used a simple three layer multicloud convection scheme in the simulation A different initiation mechanism for the MJO as opposed to the existing theory ©2013. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84889826764&doi=10.1002%2f2013GL058187&partnerID=40&md5=f8ea1c047a7e87b933bff718b55815d2
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/5593
Appears in Collections: 气候减缓与适应
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作者单位: Center for Prototype Climate Modelling, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
Recommended Citation:
Ajayamohan R.S.,Khouider B.,Majda A.J.. Realistic initiation and dynamics of the Madden-Julian Oscillation in a coarse resolution aquaplanet GCM[J]. Geophysical Research Letters,2013-01-01,40(23).