Century-long cooling trend in subpolar North Atlantic forced by atmosphere: an alternative explanation
Journal Article (Journal Article)
A well-known exception to rising sea surface temperatures (SST) across the globe is the subpolar North Atlantic, where SST has been declining at a rate of 0.39 (± 0.23) K century−1 during the 1900–2017 period. This cold blob has been hypothesized to result from a slowdown of the Atlantic Meridional Overturning Circulation (AMOC). Here, observation-based evidence is used to suggest that local atmospheric forcing can also contribute to the century-long cooling trend. Specifically, a 100-year SST trend simulated by an idealized ocean model forced by historical atmospheric forcing over the cold blob region matches 92% (± 77%) of the observed cooling trend. The data-driven simulations suggest that 54% (± 77%) of the observed cooling trend is the direct result of increased heat loss from the ocean induced by the overlying atmosphere, while the remaining 38% is due to strengthened local convection. An analysis of surface wind eddy kinetic energy suggests that the atmosphere-induced cooling may be linked to a northward migration of the jet stream, which exposes the subpolar North Atlantic to intensified storminess.
Full Text
Duke Authors
Cited Authors
- Li, L; Lozier, MS; Li, F
Published Date
- May 1, 2022
Published In
Volume / Issue
- 58 / 9-10
Start / End Page
- 2249 - 2267
Electronic International Standard Serial Number (EISSN)
- 1432-0894
International Standard Serial Number (ISSN)
- 0930-7575
Digital Object Identifier (DOI)
- 10.1007/s00382-021-06003-4
Citation Source
- Scopus