Effects of geometry on the circulation of a three-dimensional southern-hemisphere ocean model

Abstract

A series of numerical experiments on the circulation of the Antarctic region have been carried out in order to study the effect of baroclinicity and geometry on the circumpolar current and the Antarctic Convergence. Comparisons are made between model oceans which do and do not have barrier free zones (‘Drake Passage’). Limitations of computer storage require the parameters used to be somewhat different than those applicable to the ocean. However, certain conclusions can be drawn. The existence of the barrier free zone is offered as an explanation of the formation of Antarctic Intermediate Water in latitudes a little north of the latitude of Cape Horn. It is found that when the model ‘Drake Passage’ is as deep as the rest of the model ocean (which is of uniform depth), the circumpolar current is predominantly wind-driven. When the model ‘Drake Passage’ is only half as deep, the transport of the current is increased nearly three times and the predominant driving mechanism appears to be ‘thermal’.