Uncertainty quantification and global sensitivity analysis of the Los Alamos sea ice model
Journal Article
·
· Journal of Geophysical Research. Oceans
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Changes in the high-latitude climate system have the potential to affect global climate through feedbacks with the atmosphere and connections with midlatitudes. Sea ice and climate models used to understand these changes have uncertainties that need to be characterized and quantified. We present a quantitative way to assess uncertainty in complex computer models, which is a new approach in the analysis of sea ice models. We characterize parametric uncertainty in the Los Alamos sea ice model (CICE) in a standalone configuration and quantify the sensitivity of sea ice area, extent, and volume with respect to uncertainty in 39 individual model parameters. Unlike common sensitivity analyses conducted in previous studies where parameters are varied one at a time, this study uses a global variance-based approach in which Sobol' sequences are used to efficiently sample the full 39-dimensional parameter space. We implement a fast emulator of the sea ice model whose predictions of sea ice extent, area, and volume are used to compute the Sobol' sensitivity indices of the 39 parameters. Main effects and interactions among the most influential parameters are also estimated by a nonparametric regression technique based on generalized additive models. A ranking based on the sensitivity indices indicates that model predictions are most sensitive to snow parameters such as snow conductivity and grain size, and the drainage of melt ponds. Lastly, it is recommended that research be prioritized toward more accurately determining these most influential parameter values by observational studies or by improving parameterizations in the sea ice model.
- Research Organization:
- Los Alamos National Laboratory (LANL)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1325643
- Report Number(s):
- LA-UR-15-29485
- Journal Information:
- Journal of Geophysical Research. Oceans, Journal Name: Journal of Geophysical Research. Oceans Journal Issue: 4 Vol. 121; ISSN 2169-9275
- Publisher:
- American Geophysical UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
CICE, The Los Alamos Sea Ice Model
CICE, The Los Alamos Sea Ice Model
Reducing Uncertainty in High-Resolution Sea Ice Models
Software
·
Fri May 12 00:00:00 EDT 2017
·
OSTI ID:1364126
CICE, The Los Alamos Sea Ice Model
Software
·
Wed Jun 07 20:00:00 EDT 2017
·
OSTI ID:code-5455
Reducing Uncertainty in High-Resolution Sea Ice Models
Technical Report
·
Mon Jul 01 00:00:00 EDT 2013
·
OSTI ID:1090226