DOI: 10.1175/JCLI-D-16-0750.1
Scopus记录号: 2-s2.0-85022319091
论文题名: Internal intraseasonal variability of the West African monsoon in WRF
作者: Alaka G.J. ; Jr. ; Maloney E.D.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 15 起始页码: 5815
结束页码: 5833
语种: 英语
Scopus关键词: Atmospheric thermodynamics
; Atmospherics
; Budget control
; Climate change
; Kinetics
; Waves
; Weather forecasting
; Africa
; Energy budget/balance
; Intraseasonal variability
; Madden-Julian oscillation
; Regional model
; Climatology
英文摘要: The West African monsoon (WAM) and its landmark features, which include African easterly waves (AEWs) and the African easterly jet (AEJ), exhibit significant intraseasonal variability in boreal summer. However, the degree to which this variability is modulated by external large-scale phenomena, such as the Madden-Julian oscillation (MJO), remains unclear. The Weather Research and Forecasting (WRF) Model is employed to diagnose the importance of the MJO and other external influences for the intraseasonal variability of the WAM and associated AEW energetics by removing 30-90-day signals from initial and lateral boundary conditions in sensitivity tests. TheWAMproduces similar intraseasonal variability in the absence of external influences, indicating that the MJO is not critical to produce WAM variability. In control and sensitivity experiments, AEW precursor signals are similar near the AEJ entrance in East Africa. For example, an eastward extension of the AEJ increases barotropic and baroclinic energy conversions in East Africa prior to a 30-90-day maximum of perturbation kinetic energy in West Africa. TheWAMappears to prefer a faster oscillation when MJO forcing is removed, suggesting that the MJO may serve as a pacemaker for intraseasonal oscillations in the WAM. WRF results show that eastward propagating intraseasonal signals (e.g., Kelvin wave fronts) are responsible for this pacing, while the role of westward propagating intraseasonal signals (e.g., MJO-induced Rossby waves) appears to be limited. Mean state biases across the simulations complicate the interpretation of results. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/48797
Appears in Collections: 气候减缓与适应 气候变化与战略
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作者单位: Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, United States; NOAA/AOML/Hurricane Research Division, Miami, FL, United States; Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States
Recommended Citation:
Alaka G.J.,Jr.,Maloney E.D.. Internal intraseasonal variability of the West African monsoon in WRF[J]. Journal of Climate,2017-01-01,30(15)