Flare triggering by coherent oscillations.

The coherent oscillations observed by Tanaka (1972) are shown to carry very high mechanical-energy fluxes of the order of 9.5 to 45 gigaergs/sq cm per sec. This energy can provide all of the energy expended in a large flare, or at least can be used to trigger a flare. The oscillations are assumed to be free modes of the sun, as described by Wolff (1972), and they are expected to be preferentially excited in the plages where large magnetic fields provide conditions favorable to rapid growth times. The energy driving the coherent oscillations may be derived from the flux deficit of sunspots in the plage.