Magnetic explosions: role of the inductive electric field

TL;DR

This paper explores the role of the inductive electric field in magnetic explosions, especially solar flares, highlighting its influence on energy release, magnetic reconnection, particle acceleration, and emission phenomena.

Contribution

It introduces a comprehensive framework incorporating the inductive electric field into magnetic explosion models, offering new insights into flare dynamics and resolving the long-standing 'number problem.'

Findings

Inductive electric field drives the explosion's EMF.

E_ind x B drift facilitates magnetic reconnection inflow.

Parallel E_ind accelerates energetic electrons causing emissions.

Abstract

Inclusion of the inductive electric field, ${\bf E}_{\rm ind}$ due to the temporally changing ${\bf B}$, in magnetic explosions is discussed, with emphasis on solar flares. Several roles played by ${\bf E}_{\rm ind}$ are identified: on a global scale, ${\bf E}_{\rm ind}$ produces the EMF that drives the explosion; the associated ${\bf E}_{\rm ind}\times{\bf B}$ drift is identified with the inflow of magnetic field lines into a reconnection region; the polarization current, associated with $\partial{\bf E}_{\rm ind}/\partial t$, implies a ${\bf J}\times{\bf B}$ force that accelerates this inflow; and the component of ${\bf E}_{\rm ind}$ parallel to ${\bf B}$ accelerates the energetic electrons that cause hard X-ray emission and type III radio bursts. Some simple models that describe these effects are presented. A resolution of the long-standing "number problem" in solar flares is suggested.