DOI: 10.1175/JCLI-D-12-00314.1
Scopus记录号: 2-s2.0-84877662933
论文题名: Convective entrainment and large-scale organization of tropical precipitation: Sensitivity of the CNRM-CM5 hierarchy of models
作者: Oueslati B. ; Bellon G.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2013
卷: 26, 期: 9 起始页码: 2931
结束页码: 2946
语种: 英语
Scopus关键词: Coupled general circulation models
; Coupled global climate model
; Intertropical convergence zone
; Large-scale circulation
; Moisture-convection feedback
; Precipitation distribution
; South pacific convergence zones
; Tropical precipitation
; Climate models
; Distribution functions
; Probability distributions
; Lasers
; atmospheric moisture
; atmospheric plume
; climate feedback
; climate modeling
; convective system
; entrainment
; general circulation model
; intertropical convergence zone
; precipitation (climatology)
; vertical profile
; Pacific Ocean
; Pacific Ocean (Southeast)
英文摘要: The spurious double intertropical convergence zone (ITCZ) is a systematic bias affecting state-of-the-art coupled general circulation models (GCMs). Modeling studies show that the ITCZ structure is very sensitive to moist convection parameterization and in particular, to the vertical profile of convective heating and freetropospheric moistening. To further explore this sensitivity, the authors focus in this study on the influence of lateral entrainment in convective plumes on the simulated tropical precipitation and large-scale circulation. Sensitivity studies to the entrainment parameter were performed in a hierarchy of models (coupled ocean- atmosphere GCM, atmospheric GCM, and aquaplanet GCM), in order to mitigate the double ITCZ problem in the Centre National de Recherches Météorologiques Coupled Global Climate Model, version 5 (CNRMCM5). The sensitivity of the ITCZ structure to lateral entrainment is robust across our hierarchy of models. In response to increased entrainment, the realistic simulations exhibit a weakening of the southern side of the double ITCZ over the southeastern Pacific Ocean and a better representation of the South Pacific convergence zone (SPCZ). However, as a result of stronger moisture-convection feedbacks, precipitation is overestimated in the center of convergence zones. The change in ITCZ configuration is associated with a more realistic representation of the large-scale vertical regimes, explained by a decreased frequency of weak-tomoderate ascending regimes and an enhanced frequency of subsidence regimes. Mechanisms at play in this circulation change are examined by analyzing the vertically integrated dry static energy budget. This energetic analysis suggests that the feedback between large-scale dynamics and deep convection is crucial in controlling the probability distribution function (PDF) of midtropospheric vertical wind. This PDF, in turn, controls the precipitation distribution and, in particular, the double ITCZ bias. © 2013 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51905
Appears in Collections: 气候变化事实与影响
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作者单位: Centre National de Recherches Météorologiques, Centre National de Recherches Scientifiques/Météo-France, Toulouse, France
Recommended Citation:
Oueslati B.,Bellon G.. Convective entrainment and large-scale organization of tropical precipitation: Sensitivity of the CNRM-CM5 hierarchy of models[J]. Journal of Climate,2013-01-01,26(9)