DOI: 10.1002/2016MS000740
Scopus记录号: 2-s2.0-85006810877
论文题名: Coupling between lower-tropospheric convective mixing and low-level clouds: Physical mechanisms and dependence on convection scheme
作者: Vial J ; , Bony S ; , Dufresne J ; -L ; , Roehrig R
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2016
卷: 8, 期: 4 起始页码: 1892
结束页码: 1911
语种: 英语
英文关键词: Boundary layers
; Climate models
; Heat flux
; Latent heat
; Mixing
; Troposphere
; Boundary layer clouds
; Cloud feedbacks
; Convective mixing
; Convective parameterization
; Marine boundary layer clouds
; Physical mechanism
; Single-column model
; Surface latent heat fluxes
; Heat convection
; climate modeling
; cloud radiative forcing
; convective boundary layer
; convective cloud
; cooling
; latent heat flux
; marine environment
; mixing
; troposphere
英文摘要: Several studies have pointed out the dependence of low-cloud feedbacks on the strength of the lower-tropospheric convective mixing. By analyzing a series of single-column model experiments run by a climate model using two different convective parametrizations, this study elucidates the physical mechanisms through which marine boundary-layer clouds depend on this mixing in the present-day climate and under surface warming. An increased lower-tropospheric convective mixing leads to a reduction of low-cloud fraction. However, the rate of decrease strongly depends on how the surface latent heat flux couples to the convective mixing and to boundary-layer cloud radiative effects: (i) on the one hand, the latent heat flux is enhanced by the lower-tropospheric drying induced by the convective mixing, which damps the reduction of the low-cloud fraction, (ii) on the other hand, the latent heat flux is reduced as the lower troposphere stabilizes under the effect of reduced low-cloud radiative cooling, which enhances the reduction of the low-cloud fraction. The relative importance of these two different processes depends on the closure of the convective parameterization. The convective scheme that favors the coupling between latent heat flux and low-cloud radiative cooling exhibits a stronger sensitivity of low-clouds to convective mixing in the present-day climate, and a stronger low-cloud feedback in response to surface warming. In this model, the low-cloud feedback is stronger when the present-day convective mixing is weaker and when present-day clouds are shallower and more radiatively active. The implications of these insights for constraining the strength of low-cloud feedbacks observationally is discussed. © 2016. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75856
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Laboratoire de Météorologie Dynamique, Université Pierre et Marie Curie (UPMC), Paris, France; Centre National de Recherches Météorologiques - UMR 3583 Météo France/CNRS, Toulouse, France
Recommended Citation:
Vial J,, Bony S,, Dufresne J,et al. Coupling between lower-tropospheric convective mixing and low-level clouds: Physical mechanisms and dependence on convection scheme[J]. Journal of Advances in Modeling Earth Systems,2016-01-01,8(4)