Diamagnetic propulsion and energy balance of magnetic elements in the solar chromosphere and transition region

The motion and energetics of magnetic elements (plasmoids) in the solar chromosphere and transition region are considered. The magnetograph observations (Koemle, 1979) revealing an abundance of bipolar magnetic features in the network abruptly appearing and disappearing, together with the observations of Brueckner (1980) and Karpen et al. (1982) of explosive events and 'coronal bullets' as revealed in C IV, are seen as suggesting that elements of this type could be produced on a continuous basis by small-scale magnetic reconnection. It is pointed out that if this is the case and if the elements are diamagnetic with respect to the preexisting magnetic field, they would be accelerated upward in a diverging field. With these considerations in mind, the dynamics and energetics of such elements are explored for two limiting cases. The first is where the internal gas pressure of the plasmoid dominates its magnetic pressure and provides the main support against the external gas and magnetic pressure. The second is where the internal magnetic pressure dominates.