DOI: 10.1175/JCLI-D-14-00575.1
Scopus记录号: 2-s2.0-84942928215
论文题名: Roles of barotropic convective momentum transport in the intraseasonal oscillation
作者: Liu F. ; Wang B. ; Kang I.-S.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 12 起始页码: 4908
结束页码: 4920
语种: 英语
Scopus关键词: Atmospheric movements
; Boundary layers
; Climatology
; Clouds
; Momentum
; Momentum transfer
; Shear flow
; Analysis and modeling
; General circulation model
; Intraseasonal oscillations
; Madden-Julian oscillation
; Moisture convergence
; Planetary boundary layers
; Short-wave instability
; Theoretical modeling
; Tropical engineering
; atmospheric general circulation model
; atmospheric modeling
; atmospheric moisture
; atmospheric transport
; atmospheric wave
; barotropic mode
; boundary layer
; climate oscillation
; convective system
; Ekman pumping
; mixing
; parameterization
; wave propagation
; wind shear
英文摘要: Both observational data analysis and model simulations suggest that convective momentum transport (CMT) by cumulus convection may play a significant role in the intraseasonal oscillations (ISO) by redistributing atmospheric momentum vertically through fast convective mixing process. The authors present a simple theoretical model for the ISO by parameterizing the cumulus momentum transport process in which the CMT tends to produce barotropic wind anomalies that will affect the frictional planetary boundary layer (PBL). In the model with equatorial easterly vertical wind shear (VWS), it is found that the barotropic CMT tends to select most unstable planetary-scale waves because CMT suppresses the equatorial Ekman pumping of short waves, which reduces the shortwave instability from the PBL moisture convergence and accelerates the shortwave propagation. The model with subtropical easterly VWS has behavior that can be qualitatively different from the model with equatorial easterly VWS and has robust northward propagation. The basic mechanism of this northward propagation is that the CMT accelerates the barotropic cyclonic wind to the north of ISO, which will enhance the precipitation by PBL Ekman pumping and favor the northward propagation. The simulated northward propagation is sensitive to the strength and location of the seasonal-mean easterly VWS. These results suggest that accurate simulation of the climatological-mean state is critical for reproducing the realistic ISO in general circulation models. © 2015 American Meteorological Society. 资助项目: NOAA, National Research Foundation
; NRF, National Research Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50413
Appears in Collections: 气候变化事实与影响
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作者单位: Earth System Modelling Center and Climate Dynamics Research Center, Nanjing University of Information Science and Technology, Nanjing, China; International Pacific Research Center, Department of Meteorology, University of Hawai'i at Mānoa, Honolulu, HI, United States; School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
Recommended Citation:
Liu F.,Wang B.,Kang I.-S.. Roles of barotropic convective momentum transport in the intraseasonal oscillation[J]. Journal of Climate,2015-01-01,28(12)