Two-Layer Models

The subjects covered so far in this volume have been limited to fluids with homogeneous properties. Specifically, the density has always been taken as constant, although we know this is not quite true for either the ocean or atmosphere, our main areas of study in GFD. The reader will remember that we have derived the Navier–Stokes equations for earthly fluids assumed to have well-behaved solutions with a minimum of simplifying assumptions, while possible further complications have carefully been excluded.