Forced Internal Waves in the Arctic Ocean.
WASHINGTON UNIV SEATTLE DEPT OF OCEANOGRAPHY
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When the surface of an ocean is disturbed by the effects of a storm, motions may be excited in the pycnocline by the action of forced internal waves. This dissertation deals with experimental and theoretical studies of such motions. During the Arctic Mixed Layer Experiment in the Spring of 1976, manifestations of forced internal waves were observed with a new profiling current meter-CTD system. The device is unique in that it is capable of producing simultaneous, accurate profiles of density and horizontal velocity, repeatedly and at high frequency. Of particular interest are measurements made with the instrument in the upper 80 m of the ocean during a small storm which occurred April 8, 1976. During the storm the isopycnals deflected downward about 2 m and then rebounded and oscillated with periods on the order of 5 to 10 hous. Horizontal velocity perturbations at about the inertial frequency were also excited by the storm. In an effort to explain the observed motions, new theories were developed which deal with the forcing of internal waves by surface stress, atmospheric pressure and buoyancy flux. Solutions are derived for the forced motions as sums of internal wave normal modes. Arbitrary stratification is allowed below the surface mixed layer and the kinematic surface boundary condition is used.
- Physical and Dynamic Oceanography