Physical Oceanography in the Arctic Ocean: 1968

Résumé

The support of drifting stations and other scientific work on the pack ice by the Naval Arctic Research Laboratory is basic for the US studies of the central Arctic Ocean. A synoptic picture of temperature/salinity variables is needed, as is information on spatial variations of the currents. During the summer 1967, the satellite navigation system gave fixes of Fletcher's Ice Island T-3, from which water motion at depths of 150, 500 and 1300 m was recorded. Results of analyses are graphically shown and discussed; the technique used to smooth the track, noted. The flow is similar in the three water masses; a long-term period variation in the record probably represents the T-3 motion; there is a marked oscillation of ~semidiurnal period which undoubtedly represents an inertial or semidiurnal tidal oscillation. Tracks of drifting stations during 20 yr define the Beaufort gyre circulation, the center of which, 80 W, 140 W, coincides with that of a mean atmospheric pressure anticyclone. West of 140 W, the dominant W and N drifts are segments in the Transpolar Drift Stream; east of 140 W, where drifts are mainly E to W, they are in the eastern Beaufort gyre. Ice drifts faster in the Transpolar Stream than along the Canadian Islands by about 1/2 nautical mi/day; a marked increase in speed occurs in summer or fall; the atmospheric pressure gradient variations agree qualitatively with the drift speed variations. Three experiments needed to solve the principal remaining problems are explained.