Global impacts of recent Southern Ocean cooling
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Since the beginning of the satellite era, Southern Ocean sea surface temperatures (SSTs) have cooled, despite global warming. While observed Southern Ocean cooling has previously been reported to have minimal impact on the tropical Pacific, the efficiency of this teleconnection has recently shown to be mediated by subtropical cloud feedbacks that are highly model-dependent. Here, we conduct a coupled model intercomparison of paired ensemble simulations under historical radiative forcing: one with freely evolving SSTs and the other with Southern Ocean SST anomalies constrained to follow observations. We reveal a global impact of observed Southern Ocean cooling in the model with stronger (and more realistic) cloud feedbacks, including Antarctic sea–ice expansion, southeastern tropical Pacific cooling, northward-shifted Hadley circulation, Aleutian low weakening, and North Pacific warming. Our results therefore suggest that observed Southern Ocean SST decrease might have contributed to cooler conditions in the eastern tropical Pacific in recent decades.
Date Issued
2023-07-25
Date Acceptance
2023-06-06
Citation
Proceedings of the National Academy of Sciences, 2023, 120 (30), pp.1-10
ISSN
0027-8424
Publisher
Proceedings of the National Academy of Sciences
Start Page
1
End Page
10
Journal / Book Title
Proceedings of the National Academy of Sciences
Volume
120
Issue
30
Copyright Statement
Copyright © 2023 the Author(s). Published by PNAS.
This open access article is distributed under Creative
Commons Attribution-NonCommercial-NoDerivatives
License 4.0 (CC BY-NC-ND).
This open access article is distributed under Creative
Commons Attribution-NonCommercial-NoDerivatives
License 4.0 (CC BY-NC-ND).
Identifier
http://dx.doi.org/10.1073/pnas.2300881120
Publication Status
Published
Article Number
e2300881120
Date Publish Online
2023-07-17