North Atlantic climate variability in coupled models and data
Kravtsov, Sergey K.
Dewar, William K.
Berloff, Pavel S.
McWilliams, James C.
MetadataShow full item record
We show that the observed zonally averaged jet in the Northern Hemisphere atmosphere exhibits two spatial patterns with broadband variability in the decadal and inter-decadal range; these patterns are consistent with an important role of local, mid-latitude ocean–atmosphere coupling. A key aspect of this behaviour is the fundamentally nonlinear bi-stability of the atmospheric jet's latitudinal position, which enables relatively small sea-surface temperature anomalies associated with ocean processes to affect the large-scale atmospheric winds. The wind anomalies induce, in turn, complex three-dimensional anomalies in the ocean's main thermocline; in particular, they may be responsible for recently reported cooling of the upper ocean. Both observed modes of variability, decadal and inter-decadal, have been found in our intermediate climate models. One mode resembles North Atlantic tri-polar sea-surface temperature (SST) patterns described elsewhere. The other mode, with mono-polar SST pattern, is novel; its key aspects include interaction of oceanic turbulence with the large-scale oceanic flow. To the extent these anomalies exist, the interpretation of observed climate variability in terms of natural and human-induced changes will be affected. Coupled mid-latitude ocean-atmosphere modes do, however, suggest some degree of predictability is possible.
© 2008 The Authors. This work is licensed under a Creative Commons Attribution License. The definitive version was published in Nonlinear Processes in Geophysics 15 (2008): 13-24, doi:10.5194/npg-15-13-2008
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-ShareAlike 2.5 Generic
Showing items related by title, author, creator and subject.
The Subduction experiment : cruise report RRS Charles Darwin cruise number 73 subduction 3 mooring deployment and recovery cruise, 30 September-26 October 1992 Trask, Richard P.; Jenkins, William J.; Sherman, Jeffrey; McPhee, Neil M.; Ostrom, William M.; Payne, Richard E. (Woods Hole Oceanographic Institution, 1993-03)Subduction is the mechanism by which water masses formed in the mixed layer and near the surface of the ocean find their way into the upper thermocline. The subduction process and its underlying mechanisms were studied ...
Proshutinsky, Andrey; Krishfield, Richard A.; Timmermans, Mary-Louise; Toole, John M.; Carmack, Eddy C.; McLaughlin, Fiona A.; Williams, William J.; Zimmermann, Sarah; Itoh, Motoyo; Shimada, Koji (American Geophysical Union, 2009-06-24)We investigate basin-scale mechanisms regulating anomalies in freshwater content (FWC) in the Beaufort Gyre (BG) of the Arctic Ocean using historical observations and data collected in 2003–2007. Specifically, the mean ...
Whitmore, Paul; ten Brink, Uri S.; Caropolo, Michael; Huerfano-Moreno, Victor; Knight, William; Sammler, William; Sandrik, Al (Tsunami Society, 2009)West Coast/Alaska Tsunami Warning Center (WCATWC) response criteria for earthquakes occurring in the Atlantic and Caribbean basins are presented. Initial warning center decisions are based on an earthquake’s location, ...