A note on Bjerknes' hypothesis for North Atlantic variability
In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573, more
Also appears in:Nihoul, J.C.J. (Ed.) (1990). Coupled ocean-atmosphere modeling: proceedings of the 21th International Liège Colloquium on Ocean Hydrodynamics, Liège, May 8-12, 1989. Journal of Marine Systems, 1(1-3). Elsevier Scientific: Amsterdam. 313 pp., more
| |
Abstract |
On decadal time-scales the historical surface temperature record over land in the Northern Hemisphere is dominated by polar amplified variations. These variations are coherent with SST anomalies concentrated in the Northwest Atlantic, but extending with lesser amplitude into the North Pacific as well. Bierknes suggested that multi-year SST anomalies in the subpolar North Atlantic were due to irregular changes in the intensity of the thermohaline circulation. In support of the Bjerknes hypothesis there is evidence that winter overturning in the Labrador Sea was suppressed for a brief period from 1967–1969 by a cap of relative fresh water at the surface. Cause and effect are unclear, but this event was associated with a marked cooling of the entire Northern Hemisphere. |
|