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How Asymmetries Between Arctic and Antarctic Climate Sensitivity Are Modified by the Ocean
Author(s) -
Singh H. A.,
Garuba O. A.,
Rasch P. J.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl079023
Subject(s) - climatology , environmental science , northern hemisphere , forcing (mathematics) , climate model , arctic sea ice decline , arctic , climate sensitivity , southern hemisphere , arctic dipole anomaly , sea ice , arctic geoengineering , albedo (alchemy) , coupled model intercomparison project , climate change , atmospheric sciences , geology , oceanography , arctic ice pack , antarctic sea ice , art , performance art , art history
We investigate how the ocean response to CO 2 forcing affects hemispheric asymmetries in polar climate sensitivity. Intermodel comparison of Phase 5 of the Coupled Model Intercomparison Project CO 2 quadrupling experiments shows that even in models where hemispheric ocean heat uptake differences are small, Arctic warming still exceeds Antarctic warming. The polar climate impact of this evolving ocean response to CO 2 forcing is then isolated using slab ocean experiments in a state‐of‐the‐art climate model. Overall, feedbacks over the Southern Hemisphere more effectively dissipate top‐of‐atmosphere anomalies than those over the Northern Hemisphere. Furthermore, a poleward shift in ocean heat convergence in both hemispheres amplifies destabilizing ice albedo and lapse rate feedbacks over the Arctic much more so than over the Antarctic. These results suggest that the Arctic is intrinsically more sensitive to both CO 2 and oceanic forcings than the Antarctic and that ocean‐driven climate sensitivity asymmetry arises from feedback destabilization over the Arctic rather than feedback stabilization over the Antarctic.