Abstract

Magnetic reconnection has long been considered as the power for solar flares and auroral substorms. It is based on a presumption that an anti-parallel magnetic configuration annihilates itself explosively to produce the power. However, even after extensive theoretical and satellite studies, this presumptive theory is expressed as “illusive”. On the other hand, it can be shown that a photospheric dynamo for solar flares and the auroral dynamo (the solar wind-magnetospheric interaction) can generate the necessary power, 1018 W for solar flares and 1011 W for auroral substorms, based on observed value of speed and the magnetic field intensity. An explosive feature occurs, in general, as a result of a sudden release of accumulate energy. The energy can be accumulated in 5 hours in the loop current for solar flares (1024 J) and 100 minutes for auroral substorms (1017 J). The release of the accumulated energy may be caused by instability of electric current involved, for example the kink instability for solar flares and the cross-tail current instability for auroral substorms. Thus, it will be very useful to study both together, in spite of the difference of 1010 of the power and the total energy.

Keywords

magnetic reconnection, solar flare, auroral substorm, photospheric dynamo, auroral dynamo