Global Properties of Solar Flares

TL;DR

This paper reviews the global properties of solar flares, focusing on their energetics, ejection formations, and wave disturbances, emphasizing the importance of the impulsive phase and electromagnetic energy in understanding flare phenomena.

Contribution

It provides a comprehensive overview of solar flare global observables and discusses the dominance of electromagnetic energy during the impulsive phase, advancing understanding of flare energetics.

Findings

Flare radiation and CME energy are of similar magnitude (~10^32 erg).

The impulsive phase dominates the energetics of flare manifestations.

Electromagnetic fields carry most energy and momentum during the impulsive phase.

Abstract

This article broadly reviews our knowledge of solar flares. There is a particular focus on their global properties, as opposed to the microphysics such as that needed for magnetic reconnection or particle acceleration as such. Indeed solar flares will always remain in the domain of remote sensing, so we cannot observe the microscales directly and must understand the basic physics entirely via the global properties plus theoretical inference. The global observables include the general energetics -radiation in flares and mass loss in coronal mass ejections (CMEs) - and the formation of different kinds of ejection and global wave disturbance: the type II radio-burst exciter, the Moreton wave, the EIT "wave," and the "sunquake" acoustic waves in the solar interior. Flare radiation and CME kinetic energy can have comparable magnitudes, of order 10^32 erg each for an X-class event, with the bulk of the radiant energy in the visible-UV continuum. We argue that the impulsive phase of the flare dominates the energetics of all of these manifestations, and also point out that energy and momentum in this phase largely reside in the electromagnetic field, not in the observable plasma