Fall AGU Meeting (Dec. 2002) COAST abstracts:

• Allen
  
• Bane et al.
  
• Barth et al.
  
• Carney et al.
  
• Couch et al.
  
• Cowles et al.
  
• Dale et al.
  
• Durski et al.
  
• Egbert et al.
  
• Gan et al.
  
• Hales et al.
  
• Kosro et al.
  
• Kuebel et al.
  
• Kurapov et al.
  
• Perlin et al.
  
• Pierce et al.
  
• Ruttenberg et al.
  
• Samelson
  
• Spitz et al.
  
• Wheeler
  

Abstracts should be cited as:

EOS Trans. AGU, 83 (47),
Fall Meet. Suppl.,
Abstract XXXXX-XX, 2002

OS52C-0239

Three-Dimensional, Time-Dependent Flow near a Continental Shelf
Submarine Bank

J A Barth, S D Pierce, and P M Kosro

Recent advances in towed, undulating vehicle capabilities have
allowed rapid, high spatial resolution surveys of physical and
bio-optical properties to be made over the continental shelf and
slope. Together with shipboard acoustic Doppler current profiling,
this has made possible the exploration of three-dimensional,
time-dependent processes in regions with alongshore variations in
coastline geometry or bottom bathymetry. The summertime wind-driven
flow off central Oregon to the north of and over a substantial
submarine bank has been the focus of several recent studies. The
equatorward, wind-driven, mid-shelf upwelling jet flows offshore
following the isobaths as they widen around the bank. On the
downstream side of the bank, some recirculation is observed, but most
of the flow continues equatorward albeit displaced seaward of the
continental shelf break. Inshore in the ``lee'' of the bank, currents
are weaker throughout the water column and a low-temperature,
high-salinity bottom water pool is supplied from both upstream and
from recirculation. The flow-topography interaction results in an
alongshore pressure gradient that can drive northward currents on
the inner part of the shelf when winds relax. Strong northward winds
during the summertime upwelling season lead to downwelling within 15
km of the coast accompanied by significant ($\geq 0.2$~m~s$^{-1}$)
wind-driven northward currents. Seaward of this northward flow, the
equatorward jet and isopycnals sloping up toward the coast still
remain. The time-dependent and three-dimensional aspects of this
system can lead to recirculation around or retention of water on
the bank, significantly influencing the coastal ecosystem response
in this shelf region.