Energy-transfer processes in flares

Existing solar chromospheric UV and X-ray data which tend to support models for electron beam and conduction heated flares are discussed. SMM satellite X-ray data have revealed that beam heating alone is too weak to account for chromospheric heating. Thermal conduction, possibly of dissipating beam energy, has been associated with the onset of hard X-ray bursts. Furthermore, the UV output of flares is insufficient for the total flare energy to arise from electron beams and the outward bound velocities of H-alpha particles have been only a third those predicted by computer simulations of flare events initiated by electron beam evaporation of the chromosphere. It is suggested that electron beams have a negligible effect on the upper chromosphere. 38 references