The influence of several factors controlling the interactions between Prince William Sound, Alaska, and the northern Gulf of Alaska

Interactions between the circulation of Prince William Sound (PWS), Alaska, and that of the continental shelf region of the northern Gulf of Alaska are studied numerically. The focus is on the flow structure at Hinchinbrook Entrance (HE) and Montague Strait (MS) and the associated PWS interior circulation under various initial state and forcing configurations. Bottom topography inhibits flow into PWS under barotropic conditions, while stratification very much facilitates flow into PWS. Layered flow develops at HE and MS under baroclinic conditions, with two (four) layers under March (September) stratification conditions. In both baroclinic cases, the top layer transports inflow and a cyclonic eddy develops over the central basin of PWS. Westward wind (the predominant direction) enhances this upper-layer inflow and the lower-layer outflow. Eastward wind completely reverses the flow direction not only at HE but also inside PWS. Remarkably, the total outflow through MS is consistently less than the total inflow through HE; thus, there is a significant outflow through HE. Therefore, the simple throughflow-driven circulation (inflow at HE and outflow at MS) previously thought dominant needs to be re-examined.