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Weighting climate model ensembles for mean and variance estimates
Citation
Haughton, N and Abramowitz, G and Pitman, A and Phipps, SJ, Weighting climate model ensembles for mean and variance estimates, Climate Dynamics, 45, (11) pp. 3169-3181. ISSN 0930-7575 (2015) [Refereed Article]
Copyright Statement
Copyright 2015 Springer-Verlag Berlin Heidelberg
DOI: doi:10.1007/s00382-015-2531-3
Abstract
Projections based on climate model ensembles
commonly assume that each individual model simulation
is of equal value. When combining simulations to estimate
the mean and variance of quantities of interest, they
are typically unweighted. Exceptions to this approach usually
fall into two categories. First, ensembles may be pared
down by removing either poorly performing model simulations
or model simulations that are perceived to add little
additional information, typically where multiple simulations
have come from the same model. Second, weighting
methodologies, usually based on model performance differences,
may be applied, and lead to some improvement
in the projected mean. Here we compare the effect of three
different weighting techniques—simple averaging, performance
based weighting, and weighting that accounts for
model dependence—on three ensembles generated by different
approaches to model perturbation. We examine the
effect of each weighting technique on both the ensemble
mean and variance. For comparison, we also consider the
effect on the CMIP5 ensemble. While performance weighting
is shown to improve the estimate of the mean, it does
not appear to improve estimates of ensemble variance,
and may in fact degrade them. In contrast, the model independence
weighting approach appears to improve both the
ensemble mean and the variance in all ensembles.
Item Details
Item Type: | Refereed Article |
---|---|
Keywords: | climate models, ensembles, climate change, climate variability, CMIP5 |
Research Division: | Earth Sciences |
Research Group: | Climate change science |
Research Field: | Climate change processes |
Objective Division: | Environmental Policy, Climate Change and Natural Hazards |
Objective Group: | Understanding climate change |
Objective Field: | Climate change models |
UTAS Author: | Phipps, SJ (Dr Steven Phipps) |
ID Code: | 105017 |
Year Published: | 2015 |
Web of Science® Times Cited: | 22 |
Deposited By: | IMAS Research and Education Centre |
Deposited On: | 2015-12-02 |
Last Modified: | 2017-10-30 |
Downloads: | 0 |
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