气候变化领域集成服务门户(CCPortal): Cross-validation of bias-corrected climate simulations is misleading

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DOI	10.5194/hess-22-4867-2018
	Cross-validation of bias-corrected climate simulations is misleading
	Maraun D.; Widmann M.
发表日期	2018
ISSN	1027-5606
起始页码	4867
结束页码	4873
卷号	22 期号:9
英文摘要	We demonstrate both analytically and with a modelling example that cross-validation of free-running bias-corrected climate change simulations against observations is misleading. The underlying reasoning is as follows: a cross-validation can have in principle two outcomes. A negative (in the sense of not rejecting a null hypothesis), if the residual bias in the validation period after bias correction vanishes; and a positive, if the residual bias in the validation period after bias correction is large. It can be shown analytically that the residual bias depends solely on the difference between the simulated and observed change between calibration and validation periods. This change, however, depends mainly on the realizations of internal variability in the observations and climate model. As a consequence, the outcome of a cross-validation is also dominated by internal variability, and does not allow for any conclusion about the sensibility of a bias correction. In particular, a sensible bias correction may be rejected (false positive) and a non-sensible bias correction may be accepted (false negative). We therefore propose to avoid cross-validation when evaluating bias correction of free-running bias-corrected climate change simulations against observations. Instead, one should evaluate non-calibrated temporal, spatial and process-based aspects. . © 2018 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	Climate models; Bias correction; Calibration and validations; Climate change simulations; Climate simulation; Cross validation; Internal variability; Null hypothesis; Validation periods; Climate change; calibration; climate change; climate modeling; correction; model validation; modeling; observational method; simulation
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159915
作者单位	Maraun, D., Wegener Center for Climate and Global Change, University of Graz, Brandhofgasse 5, Graz, 8010, Austria; Widmann, M., School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
推荐引用方式 GB/T 7714	Maraun D.,Widmann M.. Cross-validation of bias-corrected climate simulations is misleading[J],2018,22(9).
APA	Maraun D.,&Widmann M..(2018).Cross-validation of bias-corrected climate simulations is misleading.Hydrology and Earth System Sciences,22(9).
MLA	Maraun D.,et al."Cross-validation of bias-corrected climate simulations is misleading".Hydrology and Earth System Sciences 22.9(2018).