Letter to the Editor

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

¹ Johns Hopkins Univ. Applied Physics Laboratory, Laurel, MD, USA
e-mail: glenn.mason@jhuapl.edu
² California Institute of Technology, Pasadena, CA 91125, USA
³ Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
⁴ Space Research Group, Universidad de Alcalá, Alcalá de Henares, Spain
⁵ NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
⁶ University of Texas at San Antonio, San Antonio, TX 78249, USA
⁷ University of Arizona, Tucson, AZ 85721, USA
⁸ ESA-ESAC, Madrid, Spain European Space Agency (ESA/ESAC), Villafranca del Castillo, 28692 Madrid, Spain
⁹ Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
¹⁰ Max-Planck-Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
¹¹ University of Delaware, Newark, DE 19716, USA
¹² Department of Physics, George Washington University, Washington, DC 20052, USA
¹³ University of New Hampshire, Durham, NH 03824, USA
¹⁴ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA

Received: 13 May 2021
Accepted: 17 June 2021

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 Relations Observatory-A, and the recently launched Parker Solar Probe and Solar Orbiter.

Aims. Multi-point observations of a solar particle event, combined with remote-sensing imaging of flaring, shocks, and coronal mass ejections allows for a global picture of the event to be synthesized, and made available to the modeling community to test, constrain, and refine models of particle acceleration and transport according to such parameters as shock geometries and particle mass-to-charge ratios.

Methods. Detailed measurements of heavy ion intensities, time dependence, fluences, and spectral slopes provided the required test data for this study.

Results. The heavy ion abundances, timing, and spectral forms for this event fall well within the range found in prior surveys at 1 au. The spectra were well fitted by broken power law shapes; the Fe/O ratio was somewhat lower than the average of other events. In addition, ³He/⁴He was very low, with only the upper limits established here.