The pressure field along the western margin of the North Atlantic

Publisher Website
Google Scholar
Abstract
The surface elevation field over a shelf‐slope region is subject to a parabolic differential equation, the timelike coordinate being longshore distance in the direction of propagation of vorticity waves. Two source terms in this equation contain long‐isobath and cross‐isobath density gradients. In the absence of long‐isobath variations the particular solution of the equation containing the cross‐isobath density gradient source term describes a steric setup distribution, which represents a plausible extension of the dynamic height method to shallow water. When long‐isobath variations of density are also present, the steric setup solution is complemented by a residual field, which is essentially a diffusive smoothing out of the steric setup distribution. The steric setup distribution calculated for the shelf‐slope region of the Northwest Atlantic from Cape Hatteras to the Grand Banks shows two major features: a mound of water associated with the St. Lawrence outflow and a rapid drop at the shelf break associated with an upper slope mean current having a surface velocity of the order of 20 cm s−1. The effects of the St. Lawrence outflow are felt mainly over the Scotian Shelf and in the Gulf of Maine. The shelf break current is apparently a boundary layer component of the cyclonic gyre between the Gulf Stream and the North American mainland.

This publication has 12 references indexed in Scilit: