Abstract
AbstractThe 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.
Highlights
The continued loss of Arctic sea ice is one of the most anticipated consequences of global warming, with projections for a seasonally ice-free Arctic Ocean by 2100 if current rates of greenhouse gas (GHG) emissions continue unabated [Intergovernmental Panel on Climate Change, 2013]
For the remainder of this study, we focus on the wintertime (DJF) extratropical Northern Hemisphere (NH) atmospheric response to projected Arctic sea ice loss
We have examined the NH extratropical atmospheric response to projected Arctic sea ice loss using a hierarchy of model configurations in which oceanic feedbacks are either suppressed entirely, limited to thermodynamic processes, or represented in full
Summary
The continued loss of Arctic sea ice is one of the most anticipated consequences of global warming, with projections for a seasonally ice-free Arctic Ocean by 2100 if current rates of greenhouse gas (GHG) emissions continue unabated [Intergovernmental Panel on Climate Change, 2013]. The weakened westerlies occur in association with a reduced north-south temperature gradient due to enhanced warming of the Arctic lower troposphere [Deser et al, 2010; Peings and Magnusdottir, 2014; Deser et al, 2015; Harvey et al, 2013, 2015; Sun et al, 2015]. For example, central Eurasia, Arctic sea ice loss may paradoxically lead to surface cooling as a result of an enhanced Siberian anticyclone and associated cold-air advection [Honda et al, 2009; Mori et al, 2014; Sun et al, 2015; Kug et al, 2015], this dynamical cooling is not expected to outweigh warming due to other atmospheric circulation changes in the future [Mori et al, 2014]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
