DOI: 10.5194/hess-22-4867-2018
论文题名: Cross-validation of bias-corrected climate simulations is misleading
作者: Maraun D. ; Widmann M.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2018
卷: 22, 期: 9 起始页码: 4867
结束页码: 4873
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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/163198
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Maraun D.,Widmann M.. Cross-validation of bias-corrected climate simulations is misleading[J]. Hydrology and Earth System Sciences,2018-01-01,22(9)