EGU21-15707
https://doi.org/10.5194/egusphere-egu21-15707
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Why switchbacks may be related to solar granulation 

Naïs Fargette1, Benoit Lavraud1,2, Alexis Rouillard1, Victor Réville1, Tai Phan3, Stuart D. Bale3, Thierry Dudok De Wit4, Clara Froment4, Justin Kasper5, Jasper S. Halekas6, Philippe Louarn1, Anthony W. Case7, Kelly E. Korreck7, Davin E. Larson3, David Malaspina8,9, Marc Pulupa3, Michael L. Stevens7, Phyllis L. Whittlesey3, and Matthieu Berthomier10
Naïs Fargette et al.
  • 1Institut de Recherche en Astrophysique et Planétologie, CNRS, UPS, CNES, Toulouse, France (nais.fargette@irap.omp.eu)
  • 2Laboratoire d'Astrophysique de Bordeaux , CNRS, Bordeaux, France
  • 3Space Sciences Laboratory, University of California, Berkeley, Berkeley, CA, USA
  • 4LPC2E, CNRS and University of Orléans, Orléans, France
  • 5Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, US
  • 6Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, United States
  • 7Smithsonian Astrophysical Observatory, Cambridge, Massachusetts, US
  • 8Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO, USA
  • 9Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
  • 10Laboratoire de Physique des Plasmas, CNRS, Sorbonne Universite, Ecole Polytechnique, Observatoire de Paris, Universite Paris- Saclay, Paris, France

Parker Solar Probe data below 0.3 AU have revealed a near-Sun magnetic field dominated by Alfvénic structures that display back and forth reversals of the radial magnetic field. They are called magnetic switchbacks, they display no electron strahl variation consistent with magnetic field foldings within the same magnetic sector, and are associated with velocity spikes during an otherwise calmer background. They are thought to originate either at the photosphere through magnetic reconnection processes, or higher up in the corona and solar wind through turbulent processes.

In this work, we analyze the spatial and temporal characteristic scales of these magnetic switchbacks. We define switchbacks as a deviation from the parker spiral direction and detect them automatically through perihelia encounters 1 to 6. We analyze the solid angle between the magnetic field and the parker spiral both over time and space. We perform a fast Fourier transformation to the obtained angle and find a periodical spatial variation with scales consistent with solar granulation. This suggests that switchbacks form near the photosphere and may be caused, or at least modulated, by solar convection.

How to cite: Fargette, N., Lavraud, B., Rouillard, A., Réville, V., Phan, T., Bale, S. D., Dudok De Wit, T., Froment, C., Kasper, J., Halekas, J. S., Louarn, P., Case, A. W., Korreck, K. E., Larson, D. E., Malaspina, D., Pulupa, M., Stevens, M. L., Whittlesey, P. L., and Berthomier, M.: Why switchbacks may be related to solar granulation , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15707, https://doi.org/10.5194/egusphere-egu21-15707, 2021.

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