Quasi-geostrophic wave-activity conservation law
= Quasi-geostrophic wave-activity conservation law
For linear perturbations about a uniform zonal flow, multiplying the forced quasi-geostrophic potential-vorticity equation by the PV anomaly gives a local conservation law for quadratic wave activity. Its flux is the <Eliassen–Palm flux>, and forcing or damping appears as a wave-activity source or sink.