Observation of wavelike motion of the Gaspe current.

Abstract

An unusual pattern of movement of the Gaspe Current was identified in the summer of 1978 . The axis of the current moved offshore and the deep current reversed its normal seaward direction. In satellite pictures, a wavelike structure of the Gaspe Current began to appear when the current was moving toward its normal nearshore position after a several-day excursion offshore. In a few days, it developed into a form resembling an overgrown wave, which eventually broke. Results of calculations based on Niiler and Mysak 's model of barotropic instability for a coastal jet suggest that the wavelike motion may be triggered by the increased instability of the Gaspe Current when it is away from the coast, since the effect of the coast is stabilizing.