Geophysical fluid dynamics is the study of the atmosphere and oceans using the machinery of general fluid dynamics. Much of the interest and novelty of geophysical flows derives from the fact that they take place in a rotating reference frame. The Coriolis Force, for example, is a result of this rotation, and is a very prominent feature of large scale flows. Other factors contributing to the unique character of geophysical flows include the (thermodynamical) interaction between the atmosphere and oceans and the fact that the systems under investigation are vertically arranged in stable layers (vertical density stratification).