Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability

Arctic amplification is a robust feature of climate response to global warming, with large impacts on ecosystems and societies. A long-standing mystery is that a pronounced Arctic warming occurred during the early 20th century when the rate of interdecadal change in radiative forcing was much weaker...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences
Main Authors: Tokinaga, Hiroki, Xie, Shang-Ping, Mukougawa, Hitoshi
Format: Text
Language:English
Published: National Academy of Sciences 2017
Subjects:
Online Access:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5474770/
http://www.ncbi.nlm.nih.gov/pubmed/28559341
https://doi.org/10.1073/pnas.1615880114
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Summary:Arctic amplification is a robust feature of climate response to global warming, with large impacts on ecosystems and societies. A long-standing mystery is that a pronounced Arctic warming occurred during the early 20th century when the rate of interdecadal change in radiative forcing was much weaker than at present. Here, using observations and model experiments, we show that the combined effect of internally generated Pacific and Atlantic interdecadal variabilities intensified the Arctic land warming in the early 20th century. The synchronized Pacific–Atlantic warming drastically alters planetary-scale atmospheric circulations over the Northern Hemisphere that transport warm air into the Arctic. Our results highlight the importance of regional sea surface temperature changes for Arctic climate and constrain model projections in this important region.