Record Details

Observations of the semidiurnal internal tide on the southern California slope and shelf

ScholarsArchive at Oregon State University

Field Value
Title Observations of the semidiurnal internal tide on the southern California slope and shelf
Names Lerczak, James A. (creator)
Winant, C. D. (creator)
Hendershott, M. C. (creator)
Date Issued 2003-03-12 (iso8601)
Note Copyrighted by American Geophysical Union.
Abstract We give a detailed description of the semidiurnal-band current and temperature
variability observed during the Internal Waves on the Continental Margin (IWAVES) field
experiments of 1996 and 1997 off of Mission Beach, California. This variability was
dominated by the internal tide, and the structure of the internal tide on the slope and
shelfbreak region was different from that on the narrow shelf. On the slope and shelfbreak,
the internal tide was dominated by alongshore propagating coastal-trapped waves. In this
region, semidiurnal-band currents were predominantly oriented in the alongshore
direction. In the lower half of the water column at a water depth H of 350 m, current
and temperature variability were consonant with a short wavelength (~8 km) bottom
trapped wave propagating in the alongshore direction to the north. In the upper 120 m of
the water column (above the depth of the shelfbreak), slope and shelfbreak currents were
highly coherent with a zero phase lag; that is, there was no phase propagation in the cross-shore
direction. On the narrow (~10 km) shelf, cross-shore currents u were much more
energetic than on the slope and had the structure of a mode-one internal wave. The
alongshore currents v decreased monotonically from the surface to the bottom of the water
column with a phase that did not change with depth. The near-bottom u signal propagated
toward the coast during all mooring deployments, faster in the summer than in the fall.
The near-bottom u and mid-column temperature relative phase was neither consistent with
a purely progressive nor a purely standing mode-one internal wave. We conclude that
the internal tide on the shelf was partially reflected.
Genre Article
Topic internal tide
Identifier Lerczak, J. A., C. D. Winant, and M. C. Hendershott, Observations of the semidiurnal internal tide on the southern California slope and shelf, J. Geophys. Res., 108(C3), 3068, 2003.

© Western Waters Digital Library - GWLA member projects - Designed by the J. Willard Marriott Library - Hosted by Oregon State University Libraries and Press