The Astrophysical Journal (Jan 2024)
Observations of the 2022 September 5 Solar Energetic Particle Event at 15 Solar Radii
- C. M. S. Cohen,
- R. A. Leske,
- E. R. Christian,
- A. C. Cummings,
- G. A. de Nolfo,
- M. I. Desai,
- J. Giacalone,
- M. E. Hill,
- A. W. Labrador,
- D. J. McComas,
- R. L. McNutt Jr.,
- R. A. Mewaldt,
- D. G. Mitchell,
- J. G. Mitchell,
- G. D. Muro,
- J. S. Rankin,
- N. A. Schwadron,
- T. Sharma,
- M. M. Shen,
- J. R. Szalay,
- M. E. Wiedenbeck,
- Z. G. Xu,
- O. Romeo,
- A. Vourlidas,
- S. D. Bale,
- M. Pulupa,
- J. C. Kasper,
- D. E. Larson,
- R. Livi,
- P. Whittlesey
Affiliations
- C. M. S. Cohen
- ORCiD
- California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- R. A. Leske
- ORCiD
- California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- E. R. Christian
- ORCiD
- Goddard Space Flight Center , Greenbelt, MD 20771, USA
- A. C. Cummings
- ORCiD
- California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- G. A. de Nolfo
- ORCiD
- Goddard Space Flight Center , Greenbelt, MD 20771, USA
- M. I. Desai
- ORCiD
- Southwest Research Institute , San Antonio, TX 78228, USA; University of Texas at San Antonio , San Antonio, TX 78249, USA
- J. Giacalone
- ORCiD
- University of Arizona , Tucson, AZ 85721, USA
- M. E. Hill
- ORCiD
- Johns Hopkins University Applied Physics Laboratory , Laurel, MD 20723, USA
- A. W. Labrador
- ORCiD
- California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- D. J. McComas
- ORCiD
- Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA
- R. L. McNutt Jr.
- ORCiD
- Johns Hopkins University Applied Physics Laboratory , Laurel, MD 20723, USA
- R. A. Mewaldt
- ORCiD
- California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- D. G. Mitchell
- ORCiD
- Johns Hopkins University Applied Physics Laboratory , Laurel, MD 20723, USA
- J. G. Mitchell
- ORCiD
- Goddard Space Flight Center , Greenbelt, MD 20771, USA
- G. D. Muro
- California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- J. S. Rankin
- ORCiD
- Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA
- N. A. Schwadron
- ORCiD
- Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA; University of New Hampshire , Durham, NH 03824, USA
- T. Sharma
- Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA
- M. M. Shen
- ORCiD
- Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA
- J. R. Szalay
- ORCiD
- Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA
- M. E. Wiedenbeck
- Jet Propulsion Laboratory, California Institute of Technology , Pasadena, CA 91109, USA
- Z. G. Xu
- ORCiD
- California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- O. Romeo
- ORCiD
- University of California at Berkeley , Berkeley, CA 94720, USA
- A. Vourlidas
- ORCiD
- Johns Hopkins University Applied Physics Laboratory , Laurel, MD 20723, USA
- S. D. Bale
- ORCiD
- University of California at Berkeley , Berkeley, CA 94720, USA
- M. Pulupa
- ORCiD
- University of California at Berkeley , Berkeley, CA 94720, USA
- J. C. Kasper
- ORCiD
- University of Michigan , Ann Arbor, MI 48109, USA
- D. E. Larson
- ORCiD
- University of California at Berkeley , Berkeley, CA 94720, USA
- R. Livi
- ORCiD
- University of California at Berkeley , Berkeley, CA 94720, USA
- P. Whittlesey
- ORCiD
- University of California at Berkeley , Berkeley, CA 94720, USA
- DOI
- https://doi.org/10.3847/1538-4357/ad37f8
- Journal volume & issue
-
Vol. 966,
no. 2
p. 148
Abstract
On 2022 September 5, Parker Solar Probe (Parker) observed a large solar energetic particle (SEP) event at the unprecedented distance of only 15 R _S from the Sun. The observations from the Integrated Science Investigation of the Sun (IS⊙IS) obtained over the course of this event are remarkably rich, and an overview is presented here. IS⊙IS is capable of measuring ions from 20 keV to over 100 MeV nuc ^−1 and electrons from 30 keV to 6 MeV; here, we primarily focus on the proton and helium measurements above 80 keV. Among the surprising results are evidence of inverse velocity dispersion at energies above 1 MeV during the onset of the event, a sharp decrease in the energetic particle intensities at all energies at the interplanetary shock crossing, and repeated short durations of highly anisotropic sunward flow. Many changes in the SEP intensities, anisotropy, and spectral steepness are coincident with solar wind structure boundaries identified using the Parker solar wind magnetic field and plasma data. However, there are significant changes that are not correlated with any clearly visible solar wind variation. The observations presented here serve as an introduction to a complex event with numerous opportunities for future, more in-depth studies.
Keywords
