HESS Opinions "Should we apply bias correction to global and regional climate model data?"
Top Cited Papers
Open Access
- 21 September 2012
- journal article
- Published by Copernicus GmbH in Hydrology and Earth System Sciences
- Vol. 16 (9), 3391-3404
- https://doi.org/10.5194/hess-16-3391-2012
Abstract
Despite considerable progress in recent years, output of both global and regional circulation models is still afflicted with biases to a degree that precludes its direct use, especially in climate change impact studies. This is well known, and to overcome this problem, bias correction (BC; i.e. the correction of model output towards observations in a post-processing step) has now become a standard procedure in climate change impact studies. In this paper we argue that BC is currently often used in an invalid way: it is added to the GCM/RCM model chain without sufficient proof that the consistency of the latter (i.e. the agreement between model dynamics/model output and our judgement) as well as the generality of its applicability increases. BC methods often impair the advantages of circulation models by altering spatiotemporal field consistency, relations among variables and by violating conservation principles. Currently used BC methods largely neglect feedback mechanisms, and it is unclear whether they are time-invariant under climate change conditions. Applying BC increases agreement of climate model output with observations in hindcasts and hence narrows the uncertainty range of simulations and predictions without, however, providing a satisfactory physical justification. This is in most cases not transparent to the end user. We argue that this hides rather than reduces uncertainty, which may lead to avoidable forejudging of end users and decision makers. We present here a brief overview of state-of-the-art bias correction methods, discuss the related assumptions and implications, draw conclusions on the validity of bias correction and propose ways to cope with biased output of circulation models in the short term and how to reduce the bias in the long term. The most promising strategy for improved future global and regional circulation model simulations is the increase in model resolution to the convection-permitting scale in combination with ensemble predictions based on sophisticated approaches for ensemble perturbation. With this article, we advocate communicating the entire uncertainty range associated with climate change predictions openly and hope to stimulate a lively discussion on bias correction among the atmospheric and hydrological community and end users of climate change impact studies.Keywords
This publication has 61 references indexed in Scilit:
- On the contribution of statistical bias correction to the uncertainty in the projected hydrological cycleGeophysical Research Letters, 2011
- The ERA‐Interim reanalysis: configuration and performance of the data assimilation systemQuarterly Journal of the Royal Meteorological Society, 2011
- Predictive skill of a subset of models participating in D-PHASE in the COPS regionQuarterly Journal of the Royal Meteorological Society, 2011
- Seasonal characteristics of the relationship between daily precipitation intensity and surface temperatureJournal of Geophysical Research: Atmospheres, 2009
- Bayesian multi-model projection of climate: bias assumptions and interannual variabilityClimate Dynamics, 2009
- Land‐Surface‐Atmosphere Coupling in Observations and ModelsJournal of Advances in Modeling Earth Systems, 2009
- On the need for bias correction of regional climate change projections of temperature and precipitationGeophysical Research Letters, 2008
- A summary of the PRUDENCE model projections of changes in European climate by the end of this centuryClimatic Change, 2007
- Expanded downscaling for generating local weather scenariosClimate Research, 1996
- Scale issues in hydrological modelling: A reviewHydrological Processes, 1995