DOI: 10.1175/JCLI-D-15-0327.1
Scopus记录号: 2-s2.0-84957673640
论文题名: Mechanisms of the negative shortwave cloud feedback in middle to high latitudes
作者: Ceppi P. ; Hartmann D.L. ; Webb M.J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2016
卷: 29, 期: 1 起始页码: 139
结束页码: 157
语种: 英语
Scopus关键词: Climate change
; Clouds
; Feedback
; Global warming
; Ice
; Liquids
; Oceanography
; Optical properties
; Precipitation (meteorology)
; Climate sensitivity
; Cloud microphysics
; Cloud optical depth
; Cloud water/phase
; Microphysical process
; Prognostic equations
; Sensitivity to temperatures
; Temperature dependent
; Climate models
; climate change
; cloud cover
; cloud microphysics
; cloud radiative forcing
; global warming
; optical depth
; shortwave radiation
英文摘要: Increases in cloud optical depth and liquid water path (LWP) are robust features of global warming model simulations in high latitudes, yielding a negative shortwave cloud feedback, but the mechanisms are still uncertain. Here the importance of microphysical processes for the negative optical depth feedback is assessed by perturbing temperature in the microphysics schemes of two aquaplanet models, both of which have separate prognostic equations for liquid water and ice. It is found that most of the LWP increase with warming is caused by a suppression of ice microphysical processes in mixed-phase clouds, resulting in reduced conversion efficiencies of liquid water to ice and precipitation. Perturbing the temperature-dependent phase partitioning of convective condensate also yields a small LWP increase. Together, the perturbations in large-scale microphysics and convective condensate partitioning explain more than two-thirds of the LWP response relative to a reference case with increased SSTs, and capture all of the vertical structure of the liquid water response. In support of these findings, a very robust positive relationship between monthly mean LWP and temperature in CMIP5 models and observations is shown to exist in mixed-phase cloud regions only. In models, the historical LWP sensitivity to temperature is a good predictor of the forced global warming response poleward of about 45°, although models appear to overestimate the LWP response to warming compared to observations. The results indicate that in climate models, the suppression of ice-phase microphysical processes that deplete cloud liquid water is a key driver of the LWP increase with warming and of the associated negative shortwave cloud feedback. © 2016 American Meteorological Society. 资助项目: NSF, National Science Foundation
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50215
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States; Met Office Hadley Centre, Exeter, United Kingdom
Recommended Citation:
Ceppi P.,Hartmann D.L.,Webb M.J.. Mechanisms of the negative shortwave cloud feedback in middle to high latitudes[J]. Journal of Climate,2016-01-01,29(1)