Energy Evolution from the Chromosphere to the Heliosphere in the 2021 October 28 Solar Eruption

TL;DR

This study analyzes the energy transfer and partitioning from the solar chromosphere to the heliosphere during a significant 2021 solar eruption, using multi-spacecraft observations and scaling laws.

Contribution

It provides a comprehensive energy budget for a major solar eruption, integrating remote sensing, in situ data, and scaling laws to quantify various energy components.

Findings

Total energy released matches pre-event magnetic energy estimates.

CME kinetic and potential energy dominate the energy partition.

Energy in the CME shock is quantitatively characterized.

Abstract

We perform a detailed study of the energetics for a well-observed solar eruption and flare that occurred on 28 October 2021. This event included a GOES class X1.0 flare, a global EUV wave, and a coronal mass ejection that reached speeds of >2000 km/s. The event was observed from a variety of spacecraft in NASA's Heliophysics System Observatory, including multiple missions near Earth, STEREO-A off the Sun-Earth line, and Solar Orbiter, near the Sun-Earth line at about 0.8 au. Using remote sensing, in situ observations, and in some cases scaling laws based on previous observations, we characterize the following quantities: free magnetic energy, energy in non-thermal electrons, energy in non-thermal ions, bolometric energy, energy deposited in the chromosphere, thermal energy radiated in the flare loops, energy dissipated by the EUV wave, CME kinetic and gravitational potential energy, CME energy flux in the heliosphere, and the energy partition in the CME shock. We find that the total energy released during the event is consistent with estimates of the pre-event stored magnetic energy, and the CME kinetic + potential energy dominates the energy partition.