|dc.contributor.author||Shay, Lynn K.||
|dc.contributor.author||Chang, Simon W.||
|dc.contributor.author||Elsberry, Russell L.||
|dc.identifier.citation||Journal of Physical Oceanography, Vol. 20, September 1990, pp. 1405-1424.||en_US
|dc.description.abstract||During the passage of hurricane Frederic in 1979, four ocean current meter arrays in water depths of 100-
950 m detected both a barociinic and a depth-independent response in the near-inertial frequency band. Although
the oceanic response was predominately barociinic, the hurricane excited a depth-independent component of
5-11 cm S-I.
The origin and role of the depth-independent component of velocity is investigated using a linear analytical
model and numerical simulations from a 17-level primitive equation model with a free surface. Both models
are forced with an idealized wind stress pattern based on the observed storm parameters in hurricane Frederic.
In an analytical model, the Green's function (Ko) is convolved with the wind stress curl to predict a sea surface
depression of approximately 20 cm from the equilibrium position. The near-inertial velocities are simulated by
convolving the slope of the sea surface depression with a second Green's function. The barotropic current
velocities rotate inertially with periods shifted above the local inertial period by I %-2% and the maximum
amplitude of II cm S-I is displaced to the right of the track at x = 2Rmax (radius of maximum winds).
The free surface depression simulated by the primitive-equation model is also about 18-20 cm. The primitive
equation model simulations indicate that the vertical mean pressure gradient excites 10-11 cm S-I depthaveraged
currents atx = 3Rmax . The net divergence and convergence of the horizontal velocities induces vertical
deflections of the sea surface. The spatial pattern of the barotropic amplitudes simulated by the numerical and
analytical models differ by less than 2 cm S-I in the region 0 < x < 4Rmax> which suggests that the barotropic
response to the passage of a moving hurricane is governed by linear processes.||en_US
|dc.rights||This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.||en_US
|dc.title||Free Surface Effects on the Near-Inertial Ocean Current Response to a Hurricane||en_US