气候变化领域集成服务门户(CCPortal): The impact of performance filtering on climate feedbacks in a perturbed parameter ensemble

CCPortal

DOI	10.1007/s00382-020-05281-8
	The impact of performance filtering on climate feedbacks in a perturbed parameter ensemble
	Rostron J.W.; Sexton D.M.H.; McSweeney C.F.; Yamazaki K.; Andrews T.; Furtado K.; Ringer M.A.; Tsushima Y.
发表日期	2020
ISSN	0930-7575
起始页码	521
结束页码	551
卷号	55
英文摘要	A key contribution to the latest generation of climate projections for the UK (UKCP18) was a perturbed parameter ensemble (PPE) of global coupled models based on HadGEM3-GC3.05. Together with 13 CMIP5 simulations, this PPE provides users with a dataset that samples modelling uncertainty and is ideal for use in impacts studies. Evaluations of global mean surface temperatures for this PPE have shown twenty-first century warming rates consistently at the top end of the CMIP5 range. Here we investigate one potential contributory factor to this lack of spread: that the methodology to select plausible members from a larger, related PPE of atmosphere-only experiments preferentially ruled out those predicted to have more negative climate feedbacks (i.e. lower climate sensitivities). We confirm that this is indeed the case. We show that performance in extratropical long-wave cloud forcing played a key role in this by constraining ice cloud parameters, which in turn constrained the feedback distribution (though causal links are not established). The relatively weak relationship driving this constraint is shown to arise from stronger relationships for the long-wave and short-wave cloud feedback components, which largely cancel out due to changes in tropical high clouds. Moreover, we show that the strength of these constraints is due to a structural bias in extratropical long-wave cloud forcing across the PPE. We discuss how choices made in the methodology to pick the plausible PPE members may result in an overly strong constraint when there is a structural bias and possible improvements to this methodology for the future. © 2020, The Author(s).
英文关键词	Climate feedbacks; Emergent constraints; Perturbed parameter ensembles; Sensitivity analysis
语种	英语
scopus关键词	climate modeling; computer simulation; ensemble forecasting; feedback mechanism; future prospect; numerical model; parameter estimation
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/145384
作者单位	Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, United Kingdom
推荐引用方式 GB/T 7714	Rostron J.W.,Sexton D.M.H.,McSweeney C.F.,et al. The impact of performance filtering on climate feedbacks in a perturbed parameter ensemble[J],2020,55.
APA	Rostron J.W..,Sexton D.M.H..,McSweeney C.F..,Yamazaki K..,Andrews T..,...&Tsushima Y..(2020).The impact of performance filtering on climate feedbacks in a perturbed parameter ensemble.Climate Dynamics,55.
MLA	Rostron J.W.,et al."The impact of performance filtering on climate feedbacks in a perturbed parameter ensemble".Climate Dynamics 55(2020).