Local generation of internal soliton packets in the central bay of Biscay

Abstract

Large-amplitude internal solitary waves (solitons) near the shelf break in the Bay of Biscay are now well documented and understood. A similar phenomenon recently has been reported in the central Bay, about 150 km from the nearest shelf topography. By making several transects with the ship's acoustic Doppler current profiler, we present convincing evidence that these solitons, instead of having travelled along the thermocline from the shelf break, are generated locally at about the position where the beam of internal tidal energy, originating from the shelf break, reflects from the ocean surface.