UPPER OCEAN VELOCITIES IN THE BEAUFORT-GYRE

A 23 month time series of upper ocean velocities in the Beaufort Gyre was obtained from an autonomous drifting buoy equipped with an Acousti c Doppler Current Profiler. The buoy was deployed in the Beaufort Sea and drifted over the Canada Basin, Chukchi Shelf, and Chukchi Plateau. Time-evolving spectral analysis was used to examine velocity variabil ity in three frequency bands: an eddy band (2-5 day periods), a diurna l band, and a semidiurnal band. The eddy band and the semidiurnal band dominated the horizontal kinetic energy. Although eddy energy was cle arly confined to the Beaufort Sea and Canada basin, eddies were found further to the south and west than in previous observations. The semid iurnal band was dominated by near-inertial motions with amplitude that varied seasonally (largest in late summer and smallest in late winter ). Diurnal tides were weak (< 1 cm s(-1)) except over a shallow portio n of the Chukchi Shelf.