Nonstationary Teleconnection Between the Pacific Ocean and Arctic Sea Ice

Over the last 40 years observations show a teleconnection between summertime Pacific Ocean sea surface temperatures and September Arctic sea ice extent. However, the short satellite observation record has made it difficult to further examine this relationship. Here, we use 30 fully coupled general c...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Bonan, D. B., Blanchardâ€Wrigglesworth, E.
Format: Article in Journal/Newspaper
Language:unknown
Published: American Geophysical Union 2020
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Online Access:https://doi.org/10.1029/2019gl085666
Description
Summary:Over the last 40 years observations show a teleconnection between summertime Pacific Ocean sea surface temperatures and September Arctic sea ice extent. However, the short satellite observation record has made it difficult to further examine this relationship. Here, we use 30 fully coupled general circulation models (GCMs) participating in Phase 5 of the Coupled Model Intercomparison Project to assess the ability of GCMs to simulate this teleconnection and analyze its stationarity over longer timescales. GCMs can temporarily simulate the teleconnection in continuous 40â€year segments but not over longer, centennial timescales. Each GCM exhibits considerable teleconnection variability on multidecadal timescales. Further analysis shows that the teleconnection depends on an equally nonstationary atmospheric bridge from the subequatorial Pacific Ocean to the upper Arctic troposphere. These findings indicate that the modulation of Arctic sea ice loss by subequatorial Pacific Ocean variability is not fixed in time, undermining the assumption of teleconnection stationarity as defined by the satellite record. © 2020 American Geophysical Union. Received 2 OCT 2019; Accepted 1 JAN 2020; Accepted article online 6 JAN 2020. This work benefited from insightful discussions with C. M. Bitz and J. M. Wallace. The authors are grateful for helpful comments from D. S. Battisti and F. Lehner and thank L. A. Parsons for a detailed review on a draft of this manuscript. The authors also thank the climate modeling groups for producing and making available their model output, which is accessible at the Earth System Grid Federation (ESGF) Portal (https://esgf-node.llnl.gov/search/cmip5/). E. B. W. was supported by NOAA MAPP Grant NA18OAR4310274. Published - 2019GL085666.pdf Supplemental Material - grl60083-sup-0001-figure_si-s01.pdf