inertial oscillation

A periodic motion in which the fluid inertia is balanced purely by the Coriolis force.
Fluid parcel motions are typically horizontal and circular, with constant speed and a velocity vector that constantly veers to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The inertial period, the period of an inertial oscillation, is 2π/f, where f is the Coriolis parameter.

Any function of time f(t) is periodic with period t if f(t) = f(t + τ) for all times t, where τ is the smallest number for which this equality holds.