Using SEP Pitch Angle Distributions to Estimate the Scale Size of Magnetic Switchbacks: Observations Through the Parker Solar Probe

Abstract

One of the major discoveries made by the Parker Solar Probe (PSP) was the ubiquity of S-shaped reversals in the interplanetary magnetic field called magnetic switchbacks. The structure of the magnetic field affects the acceleration and transport of solar energetic particles across the interplanetary medium. Understanding the interaction between these particles and magnetic switchbacks can help clarify how these processes work. To that end, this thesis aims to use energetic particle pitch angle distribution (PAD) data from PSP, and consequently estimate the scale size of magnetic switchbacks. From 8 years of PSP data, 25 switchback events were identified, out of which 23 could be resolved (i.e., had sufficient associated PAD data). The gyroradii of these particles were calculated and used to estimate the average switchback scale size, which was found to lie between 10000 km and 20000 km. Additionally, it was discovered that the size of switchbacks scales as a power of heliocentric distance (scale size proportional to R^{1.83}).