On natural oscillations of connected ocean basins

Natural barotropic modes are found for systems of two or three circular basins (each of uniform depth and Coriolis parameter) linked by narrow straits. They are related to the individual basin modes for various basin and strait dimensions and Coriolis parameter values. For two basins joined by a short strait, the mode frequencies intersperse one for one the combined sequence of individual basin mode frequencies. There is no comparable result for three basins. Possible effects of the North Atlantic's open boundaries on its natural oscillations and diurnal tides are considered, and also the lowest modes of Green Bay and Lake Michigan.