SeaSoar Observations Along the Southern Flank of Georges Bank

Lee, C.1 and K. Brink2and
1Applied Physics Laboratory, Universityi of Washington, Seattle, WA 98105-6698
2Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA 02543

SeaSoar measurements were made along the southern edge of Georges Bank during March 1997 (winter) and June-July 1997 (summer). The objective of the measurements was to observe fluxes of materials across the southern edge of the Bank, and to characterize them as to their importance. We report only on the physical aspects of the data set.

During the wintertime cruise, very severe weather conditions were encountered, so that it was not possible to develop a spatial time series as we had hoped. We did have enough information to say, however, that over the Bank (inside around the 70m isobath), heat and salt balances indicated a local balance with surface fluxes. In deeper waters, however, advective effects were clearly important.

During the summertime cruise, we observed the development of a massive (almost unprecedented) intrusion of Gulf Stream Ring water onto the Bank. This water had Gulf Stream-like properties and was found as far onto the Bank as about the 70 or 80m isobath. It appears that, once this water was established on the Bank, it remained there and dissipated in place. Although this was an extremely dramatic event, we argue that it was not actually a major contributor to shelf-edge exchanges over a seasonal time scale.