Are Switchback Boundaries Observed by Parker Solar Probe Closed?
Switchbacks are sudden and large deflections in the magnetic field that Parker Solar Probe frequently observes in the inner heliosphere. Their ubiquitous occurrence has prompted numerous studies to determine their nature and origin. Our goal is to describe the boundary of these switchbacks using a s...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acf99a |
| _version_ | 1797633799899578368 |
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| author | Nina Bizien Thierry Dudok de Wit Clara Froment Marco Velli Anthony W. Case Stuart D. Bale Justin Kasper Phyllis Whittlesey Robert MacDowall Davin Larson |
| author_facet | Nina Bizien Thierry Dudok de Wit Clara Froment Marco Velli Anthony W. Case Stuart D. Bale Justin Kasper Phyllis Whittlesey Robert MacDowall Davin Larson |
| author_sort | Nina Bizien |
| collection | DOAJ |
| description | Switchbacks are sudden and large deflections in the magnetic field that Parker Solar Probe frequently observes in the inner heliosphere. Their ubiquitous occurrence has prompted numerous studies to determine their nature and origin. Our goal is to describe the boundary of these switchbacks using a series of events detected during the spacecraft’s first encounter with the Sun. Using FIELDS and SWEAP data, we investigate different methods for determining the boundary normal. The observed boundaries are arc-polarized structures with a rotation that is always contained in a plane. Classical minimum variance analysis gives misleading results and overestimates the number of rotational discontinuities. We propose a robust geometric method to identify the nature of these discontinuities, which involves determining whether or not the plane that contains them also includes the origin ( B = 0). Most boundaries appear to have the same characteristics as tangential discontinuities in the context of switchbacks, with little evidence for having rotational discontinuities. We find no effect of the size of the Parker spiral deviation. Furthermore, the thickness of the boundary is within MHD scales. We conclude that most of the switchback boundaries observed by Parker Solar Probe are likely to be closed, in contrast to previous studies. Our results suggest that their erosion may be much slower than expected. |
| first_indexed | 2024-03-11T11:59:38Z |
| format | Article |
| id | doaj.art-62f078a01b1141d081bcf3fbb22d0bf5 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-11T11:59:38Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-62f078a01b1141d081bcf3fbb22d0bf52023-11-08T09:16:02ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0195812310.3847/1538-4357/acf99aAre Switchback Boundaries Observed by Parker Solar Probe Closed?Nina Bizien0https://orcid.org/0000-0001-6767-0672Thierry Dudok de Wit1https://orcid.org/0000-0002-4401-0943Clara Froment2https://orcid.org/0000-0001-5315-2890Marco Velli3https://orcid.org/0000-0002-2381-3106Anthony W. Case4https://orcid.org/0000-0002-3520-4041Stuart D. Bale5https://orcid.org/0000-0002-1989-3596Justin Kasper6https://orcid.org/0000-0002-7077-930XPhyllis Whittlesey7https://orcid.org/0000-0002-7287-5098Robert MacDowall8https://orcid.org/0000-0003-3112-4201Davin Larson9https://orcid.org/0000-0001-5030-6030LPC2E, CNRS/University of Orléans/CNES , Orléans, France ; nina.bizien@cnrs-orleans.frLPC2E, CNRS/University of Orléans/CNES , Orléans, France ; nina.bizien@cnrs-orleans.fr; International Space Science Institute , 3012, Bern, SwitzerlandLPC2E, CNRS/University of Orléans/CNES , Orléans, France ; nina.bizien@cnrs-orleans.frDepartment of Earth, Planetary, and Space Sciences, University of California , Los Angeles, CA 90095, USABWX Technologies, Inc. , Lynchburg, VA 24501, USAPhysics Department, University of California , Berkeley, CA 94720-7300, USA; Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USABWX Technologies, Inc. , Washington, DC 20002, USA; Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USASpace Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USASolar System Exploration Division, NASA/Goddard Space Flight Center , Greenbelt, MD 20771, USASpace Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USASwitchbacks are sudden and large deflections in the magnetic field that Parker Solar Probe frequently observes in the inner heliosphere. Their ubiquitous occurrence has prompted numerous studies to determine their nature and origin. Our goal is to describe the boundary of these switchbacks using a series of events detected during the spacecraft’s first encounter with the Sun. Using FIELDS and SWEAP data, we investigate different methods for determining the boundary normal. The observed boundaries are arc-polarized structures with a rotation that is always contained in a plane. Classical minimum variance analysis gives misleading results and overestimates the number of rotational discontinuities. We propose a robust geometric method to identify the nature of these discontinuities, which involves determining whether or not the plane that contains them also includes the origin ( B = 0). Most boundaries appear to have the same characteristics as tangential discontinuities in the context of switchbacks, with little evidence for having rotational discontinuities. We find no effect of the size of the Parker spiral deviation. Furthermore, the thickness of the boundary is within MHD scales. We conclude that most of the switchback boundaries observed by Parker Solar Probe are likely to be closed, in contrast to previous studies. Our results suggest that their erosion may be much slower than expected.https://doi.org/10.3847/1538-4357/acf99aSolar windInterplanetary magnetic fieldsInterplanetary discontinuities |
| spellingShingle | Nina Bizien Thierry Dudok de Wit Clara Froment Marco Velli Anthony W. Case Stuart D. Bale Justin Kasper Phyllis Whittlesey Robert MacDowall Davin Larson Are Switchback Boundaries Observed by Parker Solar Probe Closed? The Astrophysical Journal Solar wind Interplanetary magnetic fields Interplanetary discontinuities |
| title | Are Switchback Boundaries Observed by Parker Solar Probe Closed? |
| title_full | Are Switchback Boundaries Observed by Parker Solar Probe Closed? |
| title_fullStr | Are Switchback Boundaries Observed by Parker Solar Probe Closed? |
| title_full_unstemmed | Are Switchback Boundaries Observed by Parker Solar Probe Closed? |
| title_short | Are Switchback Boundaries Observed by Parker Solar Probe Closed? |
| title_sort | are switchback boundaries observed by parker solar probe closed |
| topic | Solar wind Interplanetary magnetic fields Interplanetary discontinuities |
| url | https://doi.org/10.3847/1538-4357/acf99a |
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