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.
From salty to fresh—salinity processes in the Upper-ocean Regional Study-2 (SPURS-2) : diagnosing the physics of a rainfall-dominated salinity minimum Schmitt, Raymond W.; Asher, William; Bingham, Frederick; Carton, James A.; Centurioni, Luca R.; Farrar, J. Thomas; Gordon, Arnold L.; Hodges, Benjamin A.; Jessup, Andrew T.; Kessler, William S.; Rainville, Luc; Shcherbina, Andrey Y. (The Oceanography Society, 2015-03)One of the notable features of the global ocean is that the salinity of the North Atlantic is about 1 psu higher than that of the North Pacific. This contrast is thought to be due to one of the large asymmetries in the ...
Fredericks, Janet J.; Trowbridge, John H.; Williams, Albert J.; Voulgaris, George; Shaw, William J. (Woods Hole Oceanographic Institution, 2001-08)To quantify and understand the role of vertical mixing processes in determining mid-shelf vertical structure of hydrographic and optical properties and particulate matter, the Office of Naval Research (ONR) funded a program ...
Mechanisms governing interannual variability of upper-ocean temperature in a global ocean hindcast simulation Doney, Scott C.; Yeager, Stephen G.; Danabasoglu, Gokhan; Large, William G.; McWilliams, James C. (American Meteorological Society, 2007-07)The interannual variability in upper-ocean (0–400 m) temperature and governing mechanisms for the period 1968–97 are quantified from a global ocean hindcast simulation driven by atmospheric reanalysis and satellite data ...