DOI: 10.1175/JCLI-D-15-0877.1
Scopus记录号: 2-s2.0-85015870069
论文题名: Soil moisture influence on seasonality and large-scale circulation in simulations of the West African monsoon
作者: Berg A. ; Lintner B. ; Findell K. ; Giannini A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 7 起始页码: 2295
结束页码: 2317
语种: 英语
Scopus关键词: Atmospheric thermodynamics
; Climatology
; Evaporative cooling systems
; Evapotranspiration
; Fighter aircraft
; Meteorology
; Moisture
; Precipitation (chemical)
; Soils
; Africa
; Atmosphere-land interactions
; Atmospheric circulation
; Land-atmosphere couplings
; Large-scale circulation
; Meridional temperature gradient
; Monsoon precipitation
; Monsoons
; Soil moisture
; air-soil interaction
; atmospheric circulation
; climate modeling
; evapotranspiration
; monsoon
; precipitation (climatology)
; seasonality
; soil moisture
; westerly
; West Africa
英文摘要: Prior studies have highlighted West Africa as a regional hotspot of land-atmosphere coupling. This study focuses on the large-scale influence of soil moisture variability on the mean circulation and precipitation in the West African monsoon. A suite of six models from the Global Land-Atmosphere Coupling Experiment (GLACE)-CMIP5 is analyzed. In this experiment, model integrations were performed with soil moisture prescribed to a specified climatological seasonal cycle throughout the simulation, which severs the two-way coupling between soil moisture and the atmosphere. Comparison with the control (interactive soil moisture) simulations indicates that mean June-September monsoon precipitation is enhanced when soil moisture is prescribed. However, contrasting behavior is evident over the seasonal cycle of the monsoon, with core monsoon precipitation enhanced with prescribed soil moisture but early-season precipitation reduced, at least in some models. These impacts stem from the enhancement of evapotranspiration at the dry poleward edge of the monsoon throughout the monsoon season, when soil moisture interactivity is suppressed. The early-season decrease in rainfall with prescribed soil moisture is associated with a delayed poleward advancement of the monsoon, which reflects the relative cooling of the continent from enhanced evapotranspiration, and thus a reduced land-ocean thermal contrast, prior to monsoon onset. On the other hand, during the core/late monsoon season, surface evaporative cooling modifies meridional temperature gradients and, through these gradients, alters the large-scale circulation: the midlevel African easterly jet is displaced poleward while the low-level westerlies are enhanced; this enhances precipitation. These results highlight the remote impacts of soil moisture variability on atmospheric circulation and precipitation in West Africa. © 2017 American Meteorological Society. 资助项目: NSF, Norsk Sykepleierforbund
; NSF, Norsk Sykepleierforbund
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49744
Appears in Collections: 气候变化事实与影响
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作者单位: International Research Institute for Climate and Society, Earth Institute, Columbia University, Palisades, NY, United States; Department of Environmental Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States; Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, United States
Recommended Citation:
Berg A.,Lintner B.,Findell K.,et al. Soil moisture influence on seasonality and large-scale circulation in simulations of the West African monsoon[J]. Journal of Climate,2017-01-01,30(7)