DOI: 10.1175/JCLI-D-16-0765.1
Scopus记录号: 2-s2.0-85018951297
论文题名: Fundamental causes of propagating and nonpropagating MJOs in MJOTF/GASS models
作者: Wang L. ; Li T. ; Maloney E. ; Wang B.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 10 起始页码: 3743
结束页码: 3769
语种: 英语
Scopus关键词: Budget control
; Earth atmosphere
; Moisture
; Troposphere
; Velocity
; Atmospheric general circulation models
; Eastward propagation
; General circulation model
; Madden-Julian oscillation
; Model inter comparisons
; Moist static energy
; Moisture/moisture budgets
; Numerical experiments
; Climatology
英文摘要: This study investigates the fundamental causes of differences in the Madden-Julian oscillation (MJO) eastward propagation among models that participated in a recent model intercomparison project. These models are categorized into good and poor groups characterized by prominent eastward propagation and nonpropagation, respectively. Column-integrated moist static energy (MSE) budgets are diagnosed for the good and the poor models. It is found that a zonal asymmetry in the MSE tendency, characteristic of eastward MJO propagation, occurs in the good group, whereas such an asymmetry does not exist in the poor group. The difference arises mainly from anomalous vertical and horizontal MSE advection. The former is attributed to the zonal asymmetry of upper-midtropospheric vertical velocity anomalies acting on background MSE vertical gradient; the latter is mainly attributed to the asymmetric zonal distribution of low-tropospheric meridional wind anomalies advecting background MSE and moisture fields. Based on the diagnosis above, a new mechanism for MJO eastward propagation that emphasizes the second-baroclinic-mode vertical velocity is proposed. A set of atmospheric general circulation model experiments with prescribed diabatic heating profiles was conducted to investigate the causes of different anomalous circulations between the good and the poor models. The numerical experiments reveal that the presence of a stratiform heating at the rear of MJO convection is responsible for the zonal asymmetry of vertical velocity anomaly and is important to strengthening lower-tropospheric poleward flows to the east of MJO convection. Thus, a key to improving the poor models is to correctly reproduce the stratiform heating. The roles of Rossby and Kelvin wave components in MJO propagation are particularly discussed. © 2017 American Meteorological Society. 资助项目: NSF, Norsk Sykepleierforbund
; NSFC, National Natural Science Foundation of China
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49668
Appears in Collections: 气候变化事实与影响
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作者单位: Key Lab. of Meteorological Disaster, Nanjing Univ. of Information Science and Technology, Ministry of Education/Joint International Research Lab. of Climate and Environmental Change, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing, China; International Pacific Research Center, University of Hawai'i at Manoa, Honolulu, HI, United States; School of Ocean and Earth Science and Technology, University of Hawai'i at Manoa, Honolulu, HI, United States; Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States
Recommended Citation:
Wang L.,Li T.,Maloney E.,et al. Fundamental causes of propagating and nonpropagating MJOs in MJOTF/GASS models[J]. Journal of Climate,2017-01-01,30(10)