The aurora as an electrical discharge phenomenon

Abstract:

Auroral substorms are basically an electrical discharge phenomenon. Thus, it is natural to study them in terms of a chain of processes which consist of power supply (a dynamo), currents/circuits and dissipation (auroral substotms). Based mainly a ground-based magnetometer network, it was found: (1) the magnetosphere responds (in terms of the AE index) to the power ε when it exceeds10¹¹w, (2) the aurora does not show any significant activity for about one hour after ε exceeds 10¹¹w (the growth phase), (3) thus, it is likely that the power is accumulated as magnetic energy (5x10¹¹w x one hour= 2x10¹⁵ J), (4) the dissipation rate during the expansion phase is about 5x10¹¹ w, (5) the total energy dissipated during the expansion phase is 2x10¹⁵J (2x10¹⁵J÷5x10¹¹= one hour). Based on these preliminary results, it is concluded: (a) the magnetotail cannot hold the energy (2x10¹⁵J) for a single substorm, (b) thus, the main part of the energy must be accumulated in the main body (within 10 Re) of the magnetosphere, (c) even the main body cannot hold the amount 2x10¹⁵J (or at most 10¹⁶J), (d) thus, the magnetosphere becomes unstable and release it impulsively, (e) this process is manifested as auroral substorm.