HR: 15:05h
AN: OS13C-06 [Abstracts]
TI: Modeling and Understanding Remotely Forced Rip Current Systems at the Nearshore Canyon Experiment
(NCEX)
AU: * Long, J W
EM: jlong@coas.oregonstate.edu
AF: College of Oceanic and Atmospheric Sciences, Oregon State University, 104 COAS Admin Bldg, Corvallis,
OR 97331-5503
United States
AU: \"{O}zkan-Haller, H T
EM: ozkan@coas.oregonstate.edu
AF: College of Oceanic and Atmospheric Sciences, Oregon State University, 104 COAS Admin Bldg, Corvallis,
OR 97331-5503
United States
AU: Holman, R A
EM: holman@coas.oregonstate.edu
AF: College of Oceanic and Atmospheric Sciences, Oregon State University, 104 COAS Admin Bldg, Corvallis,
OR 97331-5503
United States
AB:
Evaluation of data collected during the Nearshore Canyon Experiment, has shown that our time-dependent circulation model
(OK-Model; \"{O}zkan-Haller and Kirby, JGR, 1999), forced using radiation stress gradients derived from spectral wave models,
can predict the spatial location of large offshore directed flows (rip currents). The locations of these transient rip
currents, which are not controlled by the local nearshore bathymetry, are visible in remote sensing time exposure and
variance images due to the advection of foam on the water surface (Eos Trans. AGU, 84(46), Ocean Sci. Meet. Suppl., Abstract
OS21I-04, 2003). Further investigation has indicated that optical measurements of circulation patterns coincide with the
numerical predictions. With this validation, the numerical models are being used to evaluate the sensitivity of the dynamic
rip current system at the NCEX site to changes in wave conditions and nearshore bathymetry. Additionally, the walls of the
offshore submarine canyon contain an undulating pattern that may be important in generating small-scale variations in
waveheight, thereby driving rip currents where the water surface is at a local minimum, even in regions where the wave height
is generally high. Theoretical tests using bottom boundaries with anomalies in intermediate and deep water are being
performed to determine the effect these offshore contours can have in dictating nearshore circulation patterns. These
results will provide insight regarding the role of patterns along canyon walls in prescribing the spatial location of the rip
currents.
DE: 4263 Ocean prediction
DE: 4512 Currents
DE: 4546 Nearshore processes
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting