TY - JOUR
T1 - Quantitative characterization of spurious numerical oscillations in 48 CMIP5 models
AU - Geil, Kerrie L.
AU - Zeng, Xubin
N1 - Publisher Copyright:
© 2015. American Geophysical Union. All Rights Reserved.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2015/6/28
Y1 - 2015/6/28
N2 - Spurious numerical oscillations (SNOs) (e.g., Gibbs oscillations) can appear as unrealistic spatial waves near discontinuities or sharp gradients in global model fields (e.g., orography) and have been a known problem in global models for decades. Multiple methods of oscillation reduction exist; consequently, the oscillations are presumed small in modern climate models and hence are rarely addressed in recent literature. Here we use two metrics to quantify SNOs in 13 variables from 48 Coupled Model Intercomparison Project Phase 5 models along a Pacific ocean transect near the Andes. Results show that 48% of nonspectral models and 95% of spectral models have at least one variable with SNO amplitude as large as, or greater than, atmospheric interannual variability. The impact of SNOs on climate simulations should be thoroughly evaluated and further efforts to substantially reduce SNOs in climate models are urgently needed.
AB - Spurious numerical oscillations (SNOs) (e.g., Gibbs oscillations) can appear as unrealistic spatial waves near discontinuities or sharp gradients in global model fields (e.g., orography) and have been a known problem in global models for decades. Multiple methods of oscillation reduction exist; consequently, the oscillations are presumed small in modern climate models and hence are rarely addressed in recent literature. Here we use two metrics to quantify SNOs in 13 variables from 48 Coupled Model Intercomparison Project Phase 5 models along a Pacific ocean transect near the Andes. Results show that 48% of nonspectral models and 95% of spectral models have at least one variable with SNO amplitude as large as, or greater than, atmospheric interannual variability. The impact of SNOs on climate simulations should be thoroughly evaluated and further efforts to substantially reduce SNOs in climate models are urgently needed.
KW - global climate models
KW - model evaluation
KW - numerical approximation
KW - uncertainty quantification
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U2 - 10.1002/2015GL063931
DO - 10.1002/2015GL063931
M3 - Article
AN - SCOPUS:84948717347
VL - 42
SP - 5066
EP - 5073
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 12
ER -