Does ocean coupling matter for the northern extratropical response to projected Arctic sea ice loss?
Tomas, Robert A.
Screen, James A.
Geophysical Research Letters
American Geophysical Union (AGU)
©2016. The Authors.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivsLicense, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modiﬁcation sor adaptations are made.
The question of whether ocean coupling matters for the extratropical Northern Hemisphere atmospheric response to projected late 21st century Arctic sea ice loss is addressed using a series of experiments with Community Climate System Model version 4 at 1° spatial resolution under different configurations of the ocean model component: no interactive ocean, thermodynamic slab ocean, and full-depth (dynamic plus thermodynamic) ocean. Ocean-atmosphere coupling magnifies the response to Arctic sea ice loss but does not change its overall structure; however, a slab ocean is inadequate for inferring the role of oceanic feedbacks. The westerly winds along the poleward flank of the eddy-driven jet weaken in response to Arctic sea ice loss, accompanied by a smaller-magnitude strengthening on the equatorward side, with largest amplitudes in winter. Dynamical and thermodynamic oceanic feedbacks amplify this response by approximately 50%. Air temperature, precipitation, and sea level pressure responses also show sensitivity to the degree of ocean coupling.
R. Tomas and L. Sun gratefully acknowledge support from the Ofﬁce of Polar Programs at the National Science Foundation. J. Screen is supported by the Natural Environment Research Council. NCAR is sponsored by NSF.We appreciate the comments from the two anonymous reviewers.
This is the final version of the article. Available from the publisher via the DOI in this record.
Vol: 43, doi:10.1002/2016GL067792.