| dc.description.abstract | Several numerical experiments are carried out using the Bryan-Cox Ocean General Circulation
Model to investigate the variability of the North Atlantic thermohaline circulation
under steady, non-zonal, surface forcing and realistic geometry. To this end the annual
mean surface forcing fields were derived from the climatological data sets of Levitus (1982),
Hellerman and Rosenstein (1983) and, Schmitt et al. (1989). Further, Arctic freshwater
flux, an important part of the hydrological cycle within the North Atlantic Deep Water
formation region, is taken into account.
It is found that under present-day climatological surface forcing the system may oscillate
at interdecadal period. The mechanism driving the oscillations is linked to changes in both
the horizontal and vertical extent of convection in the northern "Labrador Sea". The
structure of the surface freshwater flux forcing plays a major role in both the initiation and
sustenance of the interdecadal oscillations. Allowing for a freshwater flux into the northern
region of tM4-abrador Sea" inhibits the interdecadal "'visibility. The oscillations, however,
appear, relatively insensitive to Arctic fresh water transport.into the "Greenland Sea".
A detailed three-dimensional discussion of the physics behind the interdecadal oscillations
is presented | en |
