final_program_abstracts[1]

11 IMSC Session Program
Perturbed physics and multimodel ensembles: How can we
use them together to constrain future climate response?
Thursday - Plenary Session 2
Ben Sanderson
Various studies have attempted to produce constraints on future climate response
using the results of ‘Perturbed Physics Ensembles’ (PPEs), which explore the
parameter uncertainty in a particular GCM. In recent work, we have demonstrated
how constraints on future climate response based upon ensemble correlations within a
PPE may not be robust when applied to a different GCM. However, by using
additional information from a multimodel ensemble such as CMIP-3, together with a
sound understanding of the feedback processes that vary within the PPE itself, we can
create a more meaningful constraint on the likely future response of the real world.
We demonstrate how a relatively small selection of features in the base climate of a
perturbed model can be used to predict the large-scale future response of that model to
greenhouse gas forcing and how constrained regression techniques can be used to
eliminate unphysical correlations from a multivariate predictor of future climate
response.
Abstracts 235