Sunward Strahl in Rapid Magnetic Field Reversals: Solar Connectivity and Magnetic Topology During Switchbacks in Parker Solar Probe's Early Encounters
Abstract
The SWEAP/SPAN-Electron sensors on Parker Solar Probe (PSP) measure the 3D distributions of solar wind electrons, including total flux, velocity, and temperature, in the inner heliosphere. Strahl electrons, which are the high energy, beam-like component of the solar wind electron population, flow outward from the sun along magnetic field lines, and thus serve as excellent tracers of magnetic topology and magnetic solar connectivity. Comparing strahl electron pitch angle distributions (PADs) to PSP/FIELDS magnetic field data, we find that, during the numerous intervals in PSP's first and second encounters where the sense of the magnetic field briefly reverses, the strahl electrons likewise reverse direction and briefly flow sunward. The strahl PADs, in agreement with measurements from the Solar Probe Cup (SPC) and SPAN-Ion instruments, therefore indicate that these intervals, termed "switchbacks", are likely not related to large-scale solar magnetic field polarity reversals, but are kinks in the magnetic field originating elsewhere and propagating outward from the sun. This work also characterizes the strahl electron population during switchback intervals compared to non-switchback periods.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH11A..06W
- Keywords:
-
- 7509 Corona;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7513 Coronal mass ejections;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7845 Particle acceleration;
- SPACE PLASMA PHYSICS;
- 7867 Wave/particle interactions;
- SPACE PLASMA PHYSICS