The roles of the atmosphere and ocean in driving Arctic warming due to European aerosol reductions

Clean air policies can have significant impacts on climate in remote regions. Previous modeling studies have shown that the temperature response to European sulfate aerosol reductions is largest in the Arctic. Here, we investigate the atmospheric and ocean roles in driving this enhanced Arctic warmi...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Krishnan, Srinath, Ekman, Annica M. L., Hansson, Hans-Christen, Riipinen, Ilona, Lewinschal, Anna, Wilcox, Laura J., Dallafior, Tanja
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 2020
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Online Access:https://centaur.reading.ac.uk/89854/
https://centaur.reading.ac.uk/89854/3/2019GL086681.pdf
https://centaur.reading.ac.uk/89854/10/GRL_EuropeanSulfArctic_submitted.pdf
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Summary:Clean air policies can have significant impacts on climate in remote regions. Previous modeling studies have shown that the temperature response to European sulfate aerosol reductions is largest in the Arctic. Here, we investigate the atmospheric and ocean roles in driving this enhanced Arctic warming using a set of fully‐coupled and slab‐ocean simulations (specified ocean heat convergence fluxes) with the Norwegian Earth system model (NorESM), under scenarios with high and low European aerosol emissions relative to year 2000. We show that atmospheric processes drive most of the Arctic response. The ocean pathway plays a secondary role inducing small temperature changes mostly in the opposite direction of the atmospheric response. Important modulators of the temperature response patterns are changes in sea‐ice extent and subsequent turbulent heat flux exchange, suggesting that a proper representation of Arctic sea‐ice and turbulent changes are key to predicting the Arctic response to mid‐latitude aerosol forcing.