INERTIAL CURRENTS IN THE BEAUFORT-SEA - OBSERVATIONS OF RESPONSE TO WIND AND SHEAR

Doppler sonar observations from the Arctic Internal Waves Experiment a nd Arctic Leads Experiment in the Beaufort Sea are used to examine cur rents below the ice during spring conditions, Following two strong win d events, the dominant fine-scale current consists of both downward an d upward propagating near-inertial internal waves. The downward propag ating waves are most evident above 100 m depth, while the upward waves are most energetic below this depth. The appearance of these waves co incides in time and depth with a westward subinertial current followin g the winds with maximum speeds of 0.05 m s(-1) at 100 m depth. Simple ray simulations show that the observed subinertial shear can signific antly refract near-inertial waves with length scales similar to those observed. In particular, waves that propagate both in the direction of the current and toward the depth of maximum current are enhanced. The se simulations suggest that the observed near-inertial wave enhancemen t is due, in part, to wave-shear effects rather than solely to surface forcing.