HR: 17:20h
AN: OS14B-02    [Abstracts]
TI: Wave Force on an Ocean Current
AU: * Sheres, D
EM: dsheres@cox.net
AF: none, 4604 E.Talmadge Dr., San Diego, CA 92116
AU: Kenyon, K E
EM: Kernken@aol.com
AF: none, 4632 North Lane, Del Mar, CA 92014
AB: Waves have linear momentum. During refraction by a shear current that momentum changes; the time rate of change of the momentum represents a force by the shear on the waves. According to Newton's third law, an equal and opposite force is applied by the waves on the shear current. We calculated the force applied by small amplitude wave on a linear shear current, uniform in depth, and find it to be proportional to the magnitude of the wave momentum multiplied by the shear; it also depends on the angle between the waves and the shear current. These results suggest that in equatorial waters, where the Coriolis force is small, wave refraction can play a role in the dynamics of large scale currents. In mid latitudes, waves with amplitudes of near 5 meters are required to apply a maximum force that will equal the Coriolis force in a current such as the Gulf Stream. In all cases the wave force will be largest at the surface and practically vanish at the depth of half a wavelength. Thus this force may affect the surface extent of ocean currents seen by remote sensing instruments. This in turn may bias estimates of transport of such currents that are based on the surface extent of their temperature signature.
DE: 4512 Currents
DE: 4560 Surface waves and tides (1222)
DE: 4572 Upper ocean and mixed layer processes
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005