Solar energetic particle heavy ion properties in the widespread event of 2020 November 29

Abstract

Context. Following a multi-year minimum of solar activity, a solar energetic particle event on 2020 Nov. 29 was observed by multiple spacecraft covering a wide range of solar longitudes including ACE, the Solar Terrestrial Observatory-A (STEREO-A), and the recently launched Parker Solar Probe (PSP) and Solar Orbiter (SOLO). Aims. Multi-point observations of a solar particle event, combined with remote-sensing imaging of flaring, shocks and coronal mass ejections allow a global picture of the event to be synthesized, and used by the modeling community to test, constrain, and refine models of particle acceleration and transport according to parameters such as shock geometries and particle mass-to-charge ratios. Methods. Measuring detailed heavy ion intensities, time dependence, fluences, and spectral slopes provide the required test data. Results. The heavy ion abundances, timing, and spectral forms for this event fall well within the range found in prior surveys at 1 au. Spectra were well fitted by broken power law shapes; the Fe/O ratio was somewhat lower that the average of other events. 3He/4He was very low, with only upper limits established.

Publication
A&A