Publication Date:
2022-05-26
Description:
During July and August of 1980 our research group measured nearsurface
water velocities near the eastern coast of Lake Huron by tracking drogues
using acoustic travel time and compass sighting techniques. The velocity
fields appeared to consist of two components. These have been termed: a
sub-current, which varied slowly with depth (compared to the deepest drogue
depth of 5.2 m) and, in most cases, was apparently in geostrophic balance with
the cross shore pressure gradient; and, a surface layer-current (defined by
the relative velocity from deeper to shallower drogues) which decayed rapidly
with depth and was directed nearly parallel with the wind and waves. There
was no discernable relationship between wind speed and relative velocity.
There was, however, a direct dependence of relative velocity with estimated
surface roughness, suggesting that Stokes drift may have been primarily responsible
for the shear. The magnitudes of the observed relative velocities
were approximately equal to Stokes drift magnitudes calculated from representative
wave energy spectra. Also reported are measurements of current and
temperature structure made prior to and following a coastal upwelling.
Description:
Prepared for the Department of Energy under Contract
DE-AC02-79EV10005 and the National Oceanic and Atmospheric
Administration under Contract 03-5-022-26.
Keywords:
Ocean currents
;
Oceanographic buoys
;
Acoustic drogue measurements
;
Nearsurface water measurement
Repository Name:
Woods Hole Open Access Server
Type:
Technical Report
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