Abstract
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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5066-5073 |
| Number of pages | 8 |
| Journal | Geophysical Research Letters |
| Volume | 42 |
| Issue number | 12 |
| DOIs | |
| State | Published - Jun 28 2015 |
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Keywords
- global climate models
- model evaluation
- numerical approximation
- uncertainty quantification
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
Cite this
Quantitative characterization of spurious numerical oscillations in 48 CMIP5 models. / Geil, Kerrie L.; Zeng, Xubin.
In: Geophysical Research Letters, Vol. 42, No. 12, 28.06.2015, p. 5066-5073.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Quantitative characterization of spurious numerical oscillations in 48 CMIP5 models
AU - Geil, Kerrie L.
AU - Zeng, Xubin
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
UR - http://www.scopus.com/inward/record.url?scp=84948717347&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84948717347&partnerID=8YFLogxK
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 -