气候变化领域集成服务门户(CCPortal): On the Increase of Climate Sensitivity and Cloud Feedback With Warming in the Community Atmosphere Models

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DOI	10.1029/2020GL089143
	On the Increase of Climate Sensitivity and Cloud Feedback With Warming in the Community Atmosphere Models
	Zhu J.; Poulsen C.J.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:18
英文摘要	Modeling and paleoclimate proxy-based studies suggest that equilibrium climate sensitivity (ECS) depends on the background climate state, though the reason is not thoroughly understood. Here we study the state dependence of ECS over a large range of global mean surface temperature (GMST) in the Community Atmosphere Model (CAM) Versions 4, 5, and 6 by varying atmospheric CO2 concentrations. We find a robust increase of ECS with GMST in all three models, albeit at different rates, which is primarily attributed to strengthening of the shortwave cloud feedback (λcld) at both high and low latitudes. Over high latitudes, increasing GMST leads to a reduction in the cloud ice fraction, weakening the (negative) cloud-phase feedback due to the phase transition of cloud ice to liquid and thereby strengthening λcld. Over low-latitude regions, increasing GMST strengthens λcld likely through the nonlinear increase in water vapor, which causes low-cloud thinning through thermodynamic and radiative processes. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Phase transitions; Climate sensitivity; Cloud feedbacks; CO2 concentration; Community atmosphere model; Global mean surface temperature; Paleoclimate proxy; Radiative process; State dependence; Climate models; atmospheric modeling; climate change; climate feedback; cloud microphysics; global warming; paleoclimate; phase transition; proxy climate record; sensitivity analysis; surface temperature
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/169760
作者单位	Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, United States; Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, United States
推荐引用方式 GB/T 7714	Zhu J.,Poulsen C.J.. On the Increase of Climate Sensitivity and Cloud Feedback With Warming in the Community Atmosphere Models[J],2020,47(18).
APA	Zhu J.,&Poulsen C.J..(2020).On the Increase of Climate Sensitivity and Cloud Feedback With Warming in the Community Atmosphere Models.Geophysical Research Letters,47(18).
MLA	Zhu J.,et al."On the Increase of Climate Sensitivity and Cloud Feedback With Warming in the Community Atmosphere Models".Geophysical Research Letters 47.18(2020).