EGU21-7879
https://doi.org/10.5194/egusphere-egu21-7879
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Discontinuity analysis and evolution of magnetic switchbacks

Mojtaba Akhavan-Tafti1, Justin Kasper1, Jia Huang1, and Stuart Bale2
Mojtaba Akhavan-Tafti et al.
  • 1Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
  • 2Department of Physics and Space Sciences Laboratory, University of California, Berkeley, California 94720, USA

Magnetic switchbacks are Alfvénic structures characterized as intervals of intermittent reversals in the radial componentof magnetic field. Switchbacks comprise of magnetic spikes preceded/succeeded by quiet, pristine solar wind. Determining switch-back generation and evolution mechanisms will further our understanding of the global circulation and transportation of Sun’s openmagnetic flux. Here, we investigate switchback transition regions using measurements from fields and plasma suites aboard the Parker SolarProbe (PSP). Minimum variance analysis (MVA) is applied on switchback transition region magnetic signatures. Discontinuity analysesare performed on 273 switchback transition regions with robust MVA solutions. Our results indicate that switchbacks are rotational discontinuities (RD) in 214 (or 78%) of the cases. 21% of the switchbacktransition regions are categorized as "either" discontinuity (ED), defined as small relative changes in both magnitude and the normalcomponent of magnetic field. RD-to-ED event count is found to reduce with increasing distance from the Sun. On average, plasmabeta falls by −28% across RD-type switchback transition regions and magnetic shear angle is 60 [deg], therefore making switchbacktransition regions theoretically favorable to local magnetic reconnection. The evolution of switchbacks away from the Sun may involve increasing mass flux across RD-type switchback transition regions. The evolution mechanism(s) remain to be discovered. Our results indicate negligible magnetic curvature across switchback transition regions which may inhibit local magnetic reconnection.

How to cite: Akhavan-Tafti, M., Kasper, J., Huang, J., and Bale, S.: Discontinuity analysis and evolution of magnetic switchbacks, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7879, https://doi.org/10.5194/egusphere-egu21-7879, 2021.

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