  The quasigeostrophic equation is a prototypical geophysical fluid model. In
this paper, we consider time-periodic motions of this model under dissipation
and time-dependent wind forcing. We show that when the wind forcing is
time-periodic and the spatial square-integral of the wind forcing is bounded in
time, the full nonlinear quasigeostrophic model has time-periodic motions,
under some conditions on $\beta$ parameter, Ekman number, viscousity and the
domain size.
