HR: 14:50h
AN: OS13C-05    [Abstracts]
TI: Observations of a semi-permanent rip current system during NCEX
AU: * Chickadel, C
EM: cchickad@coas.oregonstate.edu
AF: College of Oceanic and Atmospheric Sciences Oregon State University, 104 COAS Admin Bldg, Corvallis, OR 97331
AU: Holman, R
EM: holman@coas.oregonstate.edu
AF: College of Oceanic and Atmospheric Sciences Oregon State University, 104 COAS Admin Bldg, Corvallis, OR 97331
AB: During the 2003 Nearshore Canyon Experiment (NCEX) a recurring rip, located at the southern end of the study site, was visually observed in video images by the traces of offshore advected residual foam during larger wave events. Additional evidence of this rip was inferred from measured convergences of longshore currents from an array of 24 optical current meters, centered on the rip location. Preliminary examination of the alongshore current time series revealed interesting time and spatial variability during rip activity, including significant oscillations of the alongshore current magnitude with periods of hundreds of seconds. Our main objectives of this study are to provide quantifiable observations on the time and spatial variability of this rip current system and to examine forcing mechanisms that may control observed rip variability. Particularly, we will address how this rip's occurrence and configuration changes with wave conditions through the NCEX study. We also plan to examine the extent of direct forcing of observed rip current variability in the infragravity frequency band by surf zone pumping. We will use the optical signature of time varying surf zone width as a proxy for wave group forcing.
DE: 4275 Remote sensing and electromagnetic processes (0689)
DE: 4546 Nearshore processes
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting