Summary: | A simple linear reduced-gravity ocean model is developed to simulate the North Water polynya located in northern Baffin Bay. The model is an extension of Pease (1987) latent-heat model for a coastal polynya. Both northerly surface wind forcing and coastal upwelling processes are taken into account in modelling the steady state and time-dependent water velocities, upper layer depth, and polynya width measured southward from its northern boundary. Also, both uniform and variable wind forcing are considered. In most of this thesis a semi-infinite domain model is used in which upwelling occurs along the eastern boundary (the Greenland coast). It is found that the steady state polynya width is a strong function of the air temperature, but a weak function of the wind speed. The model results show that in the upwelling region near the Greenland coast, the polynya width is larger than further offshore (distance $>$ 2 Rossby radii), where it is a constant (the limiting Pease width). For a variable wind forcing, the southern ice edge of the North Water has a form that is similar to that of the wind forcing. In a channel, upwelling occurs in the eastern part and downwelling in the western part. Thus the polynya is much wider near Greenland and narrower near the Canadian Islands.
|