HR: 0800h
AN: OS21C-1256    [Abstracts]
TI: Zonal Currents Over the Mid-Atlantic Ridge North of 50N Observed With RAFOS Floats
AU: * Bower, A S
EM: abower@whoi.edu
AF: Woods Hole Oceanographic Institution, MS #21, Woods Hole, MA 02543 United States
AU: Richardson, P L
EM: prichardson@whoi.edu
AF: Woods Hole Oceanographic Institution, MS #21, Woods Hole, MA 02543 United States
AB: In the late 1990s, over 100 acoustically-tracked RAFOS floats were deployed at the thermocline level between 45 and 55N in the North Atlantic to investigate the warm water pathways from the subtropical to subpolar regions. This was part of the U.S. WOCE Atlantic Circulation and Climate Experiment (ACCE). The trajectories of floats released upstream (west) of the Mid-Atlantic Ridge (MAR) are analyzed here to determine how and where the various branches of the North Atlantic Current cross the MAR. They show relatively strong eddy activity upstream and downstream of the ridge axis, and the presence of several long-lived, quasi-stationary meanders and eddies immediately upstream of the ridge. In spite of this, the float trajectories generally collapse into narrow bands over the ridge axis as they are funneled over several deep gaps in the MAR, especially the Charlie-Gibbs Fracture Zone and the Faraday Fracture Zone. The high-resolution trajectories also illustrate the influence of smaller-scale features of the MAR (including seamounts and the rift valley) on the current pathways, even though the floats are up to 1500 m above the ridge crest. Fewer floats drifted westward in the northern subpolar gyre, but they too appear to be directed over gaps in the Reykjanes Ridge as they crossed from the Iceland to Irminger Basins.
UR: http://www.whoi.edu/science/PO/people/abower/ACCEmain.html
DE: 4512 Currents
DE: 4520 Eddies and mesoscale processes
DE: 4528 Fronts and jets
DE: 4532 General circulation
DE: 4536 Hydrography
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting