Arctic sea ice simulation in the PlioMIP ensemble

• Published in: Climate of the Past
• Main Authors: Howell, Fergus W., Haywood, Alan M., Otto-Bliesner, Bette L., Bragg, Fran, Chan, Wing-Le, Chandler, Mark A., Contoux, Camille, Kamae, Youichi, Abe-Ouchi, Ayako, Rosenbloom, Nan A., Stepanek, Christian, Zhang, Zhongshi
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2018
• Subjects: geo; envir; Arctic; Sea ice
• Online Access: https://doi.org/10.5194/cp-12-749-2016; https://cp.copernicus.org/articles/12/749/2016/

Eight general circulation models have simulated the mid-Pliocene warm period (mid-Pliocene, 3.264 to 3.025 Ma) as part of the Pliocene Modelling Intercomparison Project (PlioMIP). Here, we analyse and compare their simulation of Arctic sea ice for both the pre-industrial period and the mid-Pliocene. Mid-Pliocene sea ice thickness and extent is reduced, and the model spread of extent is more than twice the pre-industrial spread in some summer months. Half of the PlioMIP models simulate ice-free conditions in the mid-Pliocene. This spread amongst the ensemble is in line with the uncertainties amongst proxy reconstructions for mid-Pliocene sea ice extent. Correlations between mid-Pliocene Arctic temperatures and sea ice extents are almost twice as strong as the equivalent correlations for the pre-industrial simulations. The need for more comprehensive sea ice proxy data is highlighted, in order to better compare model performances.