•The
steady equilibrium solution is not one of rest, but is a geostrophic
balance.
•The
equation determining this steady solution contains a length scale a,
called the Rossby radius of
deformation.
•The
energy analysis indicates that energy is hard to extract from a
rotating fluid. In the problem studied,
there was an infinite amount of potential energy available for
conversion into kinetic energy, but only a finite amount of this available energy
was released. The reason was that a geostrophic equilibrium was established,
and such an equilibrium retains potential energy.