EGU22-1809
https://doi.org/10.5194/egusphere-egu22-1809
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Correlated Magnetic Field Dropouts and Plasma Wave Activity at Switchback Boundaries as Observed by Parker Solar Probe

Anthony Rasca1, William Farrell1, Robert MacDowall1, Stuart Bale2, and Justin Kasper3
Anthony Rasca et al.
  • 1NASA/Goddard Space Flight Center, Greenbelt, MD, USA
  • 2Space Science Laboratory, University of California, Berkeley, CA, USA
  • 3Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA

The first solar encounters by the Parker Solar Probe revealed the magnetic field to be dominated by short field reversals in the radial direction referred to as "switchbacks."  While radial velocity and proton temperature were shown to increase inside the switchbacks, B exhibits very brief dropouts only at the switchback boundaries.  Brief intensifications in spectral density measurements near the electron plasma frequency, fpe, have also been observed at these boundaries, indicating the presence of plasma waves triggered by electron beams.  We perform a correlative study using observations from the Parker FIELDS Radio Frequency Spectrometer (RFS) and Fluxgate Magnetometer (MAG) to compare occurrences of spectral density intensifications at the electron plasma frequency (fpe intensifications) and B dropouts at switchback boundaries during Parker's first and second solar encounters.  We find that only a small fraction of minor B dropouts are associated with fpe intensifications.  This fraction increases with B dropout size until all dropouts are associated with fpe intensifications.  This suggests that in the presence of strong B dropouts, electron currents that create the perturbation in B along the boundaries are also stimulating plasma waves such as Langmuir waves.

How to cite: Rasca, A., Farrell, W., MacDowall, R., Bale, S., and Kasper, J.: Correlated Magnetic Field Dropouts and Plasma Wave Activity at Switchback Boundaries as Observed by Parker Solar Probe, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1809, https://doi.org/10.5194/egusphere-egu22-1809, 2022.

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