North Atlantic Subtropical Gyre: SOFAR Floats Tracked by Moored Listening Stations

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Science  24 Jul 1981:
Vol. 213, Issue 4506, pp. 435-437
DOI: 10.1126/science.213.4506.435


In 1980, SOFAR (sound fixing and ranging) floats were tracked acoustically in the western North Atlantic entirely by means of moored autonomous listening stations. During a 5-month period 17 float trajectories were obtained in the eastern (45° to 65°W) Gulf Stream and subtropical gyre interior at depths of 700 and 2000 meters. These mid-depth trajectories suggest a time-varying Gulf Stream with instances of both a narrow, swift, westward recirculation south of the stream and a northeastward penetration into the Newfoundland Basin. A hundredfold increase of eddy kinetic energy was observed at 2000 meters from the gyre interior (south of 30°N) to the Gulf Stream.