nerc.ac.uk

On the robustness of emergent constraints used in multimodel climate change projections of Arctic warming

Bracegirdle, Thomas J.; Stephenson, David B.. 2013 On the robustness of emergent constraints used in multimodel climate change projections of Arctic warming. Journal of Climate, 26 (2). 669-678. 10.1175/JCLI-D-12-00537.1

Before downloading, please read NORA policies.
[img]
Preview
Text
JCLI-D-12-00537.pdf - Published Version

Download (3MB) | Preview

Abstract/Summary

Statistical relationships between future and historical model runs in multimodel ensembles (MMEs) are increasingly exploited to make more constrained projections of climate change. However, such emergent constraints may be spurious and can arise because of shared (common) errors in a particular MME or because of overly influential models. This study assesses the robustness of emergent constraints used for Arctic warming by comparison of such constraints in ensembles generated by the two most recent Coupled Model Intercomparison Project (CMIP) experiments: CMIP3 and CMIP5. An ensemble regression approach is used to estimate emergent constraints in Arctic wintertime surface air temperature change over the twenty-first century under the Special Report on Emission Scenarios (SRES) A1B scenario in CMIP3 and the Representative Concentration Pathway (RCP) 4.5 scenario in CMIP5. To take account of different scenarios, this study focuses on polar amplification by using temperature responses at each grid point that are scaled by the global mean temperature response for each climate model. In most locations, the estimated emergent constraints are reassuringly similar in CMIP3 and CMIP5 and differences could have easily arisen from sampling variation. However, there is some indication that the emergent constraint and polar amplification is substantially larger in CMIP5 over the Sea of Okhotsk and the Bering Sea. Residual diagnostics identify one climate model in CMIP5 that has a notable influence on estimated emergent constraints over the Bering Sea and one in CMIP3 that that has a notable influence more widely along the sea ice edge and into midlatitudes over the western North Atlantic

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1175/JCLI-D-12-00537.1
Programmes: BAS Programmes > Polar Science for Planet Earth (2009 - ) > Climate
ISSN: 0894-8755
Additional Information. Not used in RCUK Gateway to Research.: © Copyright 2013 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyright@ametsoc.org.
Additional Keywords: Arctic, regression analysis, climate models, general circulation models, model comparison, model/evaluation performance
Date made live: 02 Apr 2013 12:36
URI: http://nora.nerc.ac.uk/id/eprint/500803

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...