A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons
In this work, more than a dozen solar energetic particle (SEP) events are identified where the source region is magnetically well connected to at least one spacecraft at 1 au. The observed intensity–time profiles, for all available proton and electron energy channels, are compared to results compute...
| الحاوية / القاعدة: | The Astrophysical Journal |
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| المؤلفون الرئيسيون: | , , , , , , |
| التنسيق: | مقال |
| اللغة: | الإنجليزية |
| منشور في: |
IOP Publishing
2024-01-01
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| الموضوعات: | |
| الوصول للمادة أونلاين: | https://doi.org/10.3847/1538-4357/ad55c3 |
| _version_ | 1850296264788279296 |
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| author | J. T. Lang R. D. Strauss N. E. Engelbrecht J. P. van den Berg N. Dresing D. Ruffolo R. Bandyopadhyay |
| author_facet | J. T. Lang R. D. Strauss N. E. Engelbrecht J. P. van den Berg N. Dresing D. Ruffolo R. Bandyopadhyay |
| author_sort | J. T. Lang |
| collection | DOAJ |
| container_title | The Astrophysical Journal |
| description | In this work, more than a dozen solar energetic particle (SEP) events are identified where the source region is magnetically well connected to at least one spacecraft at 1 au. The observed intensity–time profiles, for all available proton and electron energy channels, are compared to results computed using a numerical one-dimensional SEP transport model in order to derive the parallel mean free paths (pMFPs) as a function of energy (or rigidity) at 1 au. These inversion results are then compared to theoretical estimates of the pMFP, using observed turbulence quantities with observationally motivated variations as input. For protons, a very good comparison between inversion and theoretical results is obtained. It is shown that the observed inter-event variations in the inversion pMFP values can be explained by natural variations in the background turbulence values. For electrons, there is relatively good agreement with pMFPs derived assuming the damping model of dynamical turbulence, although the theoretical values are extremely sensitive to the details of the turbulence dissipation range, which themselves display a high level of variation. |
| format | Article |
| id | doaj-art-e9905e98fe7d4b5db8e3558ea40cdd67 |
| institution | Directory of Open Access Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| spelling | doaj-art-e9905e98fe7d4b5db8e3558ea40cdd672025-08-19T23:33:04ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01971110510.3847/1538-4357/ad55c3A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and ElectronsJ. T. Lang0https://orcid.org/0000-0001-6120-7740R. D. Strauss1https://orcid.org/0000-0002-0205-0808N. E. Engelbrecht2https://orcid.org/0000-0003-3659-7956J. P. van den Berg3N. Dresing4https://orcid.org/0000-0003-3903-4649D. Ruffolo5https://orcid.org/0000-0003-3414-9666R. Bandyopadhyay6https://orcid.org/0000-0002-6962-0959Center for Space Research, North-West University , Potchefstroom, South AfricaCenter for Space Research, North-West University , Potchefstroom, South Africa; National Institute for Theoretical and Computational Sciences (NITheCS) , Potchefstroom, South AfricaCenter for Space Research, North-West University , Potchefstroom, South AfricaCenter for Space Research, North-West University , Potchefstroom, South AfricaDepartment of Physics and Astronomy, University of Turku , Turku, FinlandDepartment of Physics, Faculty of Science, Mahidol University , Bangkok, ThailandDepartment of Astrophysical Sciences, Princeton University , Princeton, USAIn this work, more than a dozen solar energetic particle (SEP) events are identified where the source region is magnetically well connected to at least one spacecraft at 1 au. The observed intensity–time profiles, for all available proton and electron energy channels, are compared to results computed using a numerical one-dimensional SEP transport model in order to derive the parallel mean free paths (pMFPs) as a function of energy (or rigidity) at 1 au. These inversion results are then compared to theoretical estimates of the pMFP, using observed turbulence quantities with observationally motivated variations as input. For protons, a very good comparison between inversion and theoretical results is obtained. It is shown that the observed inter-event variations in the inversion pMFP values can be explained by natural variations in the background turbulence values. For electrons, there is relatively good agreement with pMFPs derived assuming the damping model of dynamical turbulence, although the theoretical values are extremely sensitive to the details of the turbulence dissipation range, which themselves display a high level of variation.https://doi.org/10.3847/1538-4357/ad55c3Cosmic raysHeliosphereSolar windInterplanetary turbulenceSolar energetic particles |
| spellingShingle | J. T. Lang R. D. Strauss N. E. Engelbrecht J. P. van den Berg N. Dresing D. Ruffolo R. Bandyopadhyay A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons Cosmic rays Heliosphere Solar wind Interplanetary turbulence Solar energetic particles |
| title | A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons |
| title_full | A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons |
| title_fullStr | A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons |
| title_full_unstemmed | A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons |
| title_short | A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons |
| title_sort | detailed survey of the parallel mean free path of solar energetic particle protons and electrons |
| topic | Cosmic rays Heliosphere Solar wind Interplanetary turbulence Solar energetic particles |
| url | https://doi.org/10.3847/1538-4357/ad55c3 |
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