DOI: 10.1175/JCLI-D-16-0785.1
Scopus记录号: 2-s2.0-85022326316
论文题名: A moist static energy budget-based analysis of the Sahel rainfall response to uniform oceanic warming
作者: Hill S.A. ; Ming Y. ; Held I.M. ; Zhao M.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 15 起始页码: 5637
结束页码: 5660
语种: 英语
Scopus关键词: Budget control
; Climate change
; Global warming
; Oceanography
; Parameterization
; Precipitation (chemical)
; Rain
; Subsidence
; Troposphere
; Atmospheric components
; Convective parameterization
; Energy transport
; Geophysical fluid dynamics laboratories
; Horizontal advection
; Large-scale precipitation
; Monsoons
; University of Washington
; Climate models
英文摘要: Climate models generate a wide range of precipitation responses to global warming in the African Sahel, but all that use the NOAA Geophysical Fluid Dynamics Laboratory AM2.1 model as their atmospheric component dry the region sharply. This study compares the Sahel's wet season response to uniform 2-K SST warming in AM2.1 using either its default convective parameterization, relaxed Arakawa-Schubert (RAS), or an alternate, the University of Washington (UW) parameterization, using the moist static energy (MSE) budget to diagnose the relevant mechanisms. UW generates a drier, cooler control Sahel climate than does RAS and a modest rainfall increase with SST warming rather than a sharp decrease. Horizontal advection of dry, low-MSE air from the Sahara Desert-a leading-order term in the control MSE budget with either parameterization-is enhanced with oceanic warming, driven by enhanced meridional MSE and moisture gradients spanning the Sahel. With RAS, this occurs throughout the free troposphere and is balanced by anomalous MSE import through anomalous subsidence, which must be especially large in the midtroposphere where the moist static stability is small. With UW, the strengthening of the meridional MSE gradient is mostly confined to the lower troposphere, due in part to comparatively shallow prevailing convection. This necessitates less subsidence, enabling convective and total precipitation to increase with UW, although both large-scale precipitation and precipitation minus evaporation decrease. This broad set of hydrological and energetic responses persists in simulations with SSTs varied over a wide range. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/48788
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: Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, United States; NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States; University Corporation for Atmospheric Research, Boulder, CO, United States; Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, United States; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
Recommended Citation:
Hill S.A.,Ming Y.,Held I.M.,et al. A moist static energy budget-based analysis of the Sahel rainfall response to uniform oceanic warming[J]. Journal of Climate,2017-01-01,30(15)