HR: 10:20h
AN: OS32B-01    [Abstracts]
TI: The Western North Atlantic Shelfbreak Current System
AU: * Fratantoni, P S
EM: pfratantoni@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole, MA 02543 United States
AU: Pickart, R S
EM: rpickart@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole, MA 02543 United States
AB: Twelve years of historical hydrographic data, spanning the period 1990-2001, were analyzed to examine the alongstream evolution of the western North Atlantic shelfbreak front and current, following its path from Cape Farewell, Greenland, to its termination near Cape Hatteras, North Carolina. Over 700 synoptic sections were used to construct a mean three-dimensional description of the structure of the shelfbreak front, and quantify changes in properties, including frontal strength and grounding position. The hydrographic sections were also used to examine the evolution of the baroclinic velocity field and its associated volume transport. Our detailed view reveals that there are actually two fronts in the northern part of the domain - an inshore front located near the shelfbreak, and a deeper front centered in the core of Irminger Sea Water over the upper slope. However, we were only able to distinguish a single baroclinic velocity core. The deeper Irminger Front disappears with the erosion of the Irminger Water near the Tail of the Grand Banks while the inshore front is identifiable through the Middle Atlantic Bight. The two fronts vary differently with downstream distance but, regardless of the width of the shelf and the depth of the shelfbreak, the foot of the shelfbreak front remains within 20 km of the shelfbreak. This suggests that, although the position of the surface outcrop of the front varies substantially from region to region, the foot of the front is tied to the shelfbreak.
DE: 4528 Fronts and jets
DE: 4532 General circulation
DE: 4536 Hydrography
DE: 4576 Western boundary currents
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting