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Sunday, August 26, 2012

"Trends in Arctic sea ice extent from CMIP5, CMIP3 and observations," Julienne C. Stroeve et al., GRL 39 (2012); doi: 10.1029/2012GL052676

Geophysical Research Letters, 39 (2012) L16502; doi: 10.1029/2012GL052676
Trends in Arctic sea ice extent from CMIP5, CMIP3 and observations
Key Points
  • CMIP5 models continue to underestimate rate of sea ice loss
  • CMIP5 models are more consistent with observations than CMIP3
  • CMIP5 suggests 60% of 1979-2011 rate of decline is externally forced
Julienne C. Stroeve (National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, U.S.A.), Vladimir Kattsov (Voeikov Main Geophysical Observatory, Roshydromet, St. Petersburg, Russia) and  Andrew Barrett and Mark Serreze (National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, U.S.A.),  Tatiana Pavlova (Voeikov Main Geophysical Observatory, Roshydromet, St. Petersburg, Russia), Marika Holland (National Center for Atmospheric Research, Boulder, CO, U.S.A.) and Walter N. Meier (National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, U.S.A.)

Abstract

The rapid retreat and thinning of the Arctic sea ice cover over the past several decades is one of the most striking manifestations of global climate change. Previous research revealed that the observed downward trend in September ice extent exceeded simulated trends from most models participating in the World Climate Research Programme Coupled Model Intercomparison Project Phase 3 (CMIP3). We show here that as a group, simulated trends from the models contributing to CMIP5 are more consistent with observations over the satellite era (1979–2011). Trends from most ensemble members and models nevertheless remain smaller than the observed value. Pointing to strong impacts of internal climate variability, 16% of the ensemble member trends over the satellite era are statistically indistinguishable from zero. Results from the CMIP5 models do not appear to have appreciably reduced uncertainty as to when a seasonally ice-free Arctic Ocean will be realized.
Received 7 June 2012; accepted 17 July 2012; published 25 August 2012.
Stroeve, J. C., V. Kattsov, A. Barrett, M. Serreze, T. Pavlova, M. Holland, and W. N. Meier (2012), Trends in Arctic sea ice extent from CMIP5, CMIP3 and observationsGeophys. Res. Lett.39, L16502, doi: 10.1029/2012GL052676.

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