Low-Frequency Free Wave and Wind-Driven Motions Over a Submarine Bank

Abstract

Abstract This study attempts to isolate the physics peculiar to a submarine bank. The particular model is barotropic and contains an infinitely long straight bank within an unbounded ocean basin. The low-frequency, free wave solutions consist of two infinite sets of model analogous to barotropic continental shelf waves, one set trapped to each side of the bank. In addition, a severely distorted double Kelvin wave is associated with the net depth difference across the bank. Inclusion of bottom friction representative of Georges Bank suggests that only one free wave (westward propagating on the South side) will have a sufficiently long decay time to be likely to be observed in nature. The spatial variation in local spindown time also causes the lines of constant wave phase to be no longer perpendicular to the isobaths. Steady, forward motions are considered for winds which vary slowly in the alongbank direction. When the Ekman scale depth is the same order as the minimal depth over the bank, the primary dri...