Global Energetics of Thirty-Eight Large Solar Eruptive Events

TL;DR

This study comprehensively quantifies the energetics of 38 large solar eruptive events, revealing the relationships among radiated energy, energetic particles, CMEs, and magnetic energy, providing insights into the energy distribution in solar eruptions.

Contribution

It provides the first detailed, multi-component energetic analysis of a sizable sample of solar eruptions, integrating observations across various instruments and energy forms.

Findings

SXR radiated energy exceeds thermal plasma energy by about half an order of magnitude.

Energy in flare-accelerated particles is sufficient for the total radiated energy.

SEP energy is a few percent of CME kinetic energy.

Abstract

We have evaluated the energetics of 38 solar eruptive events observed by a variety of spacecraft instruments between February 2002 and December 2006, as accurately as the observations allow. The measured energetic components include: (1) the radiated energy in the GOES 1 - 8 A band; (2) the total energy radiated from the soft X-ray (SXR) emitting plasma; (3) the peak energy in the SXR-emitting plasma; (4) the bolometric radiated energy over the full duration of the event; (5) the energy in flare-accelerated electrons above 20 keV and in flare-accelerated ions above 1 MeV; (6) the kinetic and potential energies of the coronal mass ejection (CME); (7) the energy in solar energetic particles (SEPs) observed in interplanetary space; and (8) the amount of free (nonpotential) magnetic energy estimated to be available in the pertinent active region. Major conclusions include: (1) the energy radiated by the SXR-emitting plasma exceeds, by about half an order of magnitude, the peak energy content of the thermal plasma that produces this radiation; (2) the energy content in flare-accelerated electrons and ions is sufficient to supply the bolometric energy radiated across all wavelengths throughout the event; (3) the energy contents of flare-accelerated electrons and ions are comparable; (4) the energy in SEPs is typically a few percent of the CME kinetic energy (measured in the rest frame of the solar wind); and (5) the available magnetic energy is sufficient to power the CME, the flare-accelerated particles, and the hot thermal plasma.