Observations of Energetic-Particle Population Enhancements along Intermittent Structures near the Sun from Parker Solar Probe

TL;DR

This study uses Parker Solar Probe data to analyze the correlation between energetic particle enhancements and intermittent magnetic structures near the Sun, revealing non-Poissonian, power-law waiting time distributions that suggest complex particle transport and acceleration processes.

Contribution

It provides the first analysis of energetic particle correlations close to the Sun, showing power-law waiting time distributions and potential new behaviors, advancing understanding of solar energetic particle origins.

Findings

Power-law distribution of waiting times indicates correlated processes.

Results are consistent with previous 1 au studies but show hints of unexpected behavior.

Insights into particle transport and acceleration mechanisms near the Sun.

Abstract

Observations at 1 au have confirmed that enhancements in measured energetic particle fluxes are statistically associated with "rough" magnetic fields, i.e., fields having atypically large spatial derivatives or increments, as measured by the Partial Variance of Increments (PVI) method. One way to interpret this observation is as an association of the energetic particles with trapping or channeling within magnetic flux tubes, possibly near their boundaries. However, it remains unclear whether this association is a transport or local effect; i.e., the particles might have been energized at a distant location, perhaps by shocks or reconnection, or they might experience local energization or re-acceleration. The Parker Solar Probe (PSP), even in its first two orbits, offers a unique opportunity to study this statistical correlation closer to the corona. As a first step, we analyze the separate correlation properties of the energetic particles measured by the \isois instruments during the first solar encounter. The distribution of time intervals between a specific type of event, i.e., the waiting time, can indicate the nature of the underlying process. We find that the \isois observations show a power-law distribution of waiting times, indicating a correlated (non-Poisson) distribution. Analysis of low-energy \isois data suggests that the results are consistent with the 1 au studies, although we find hints of some unexpected behavior. A more complete understanding of these statistical distributions will provide valuable insights into the origin and propagation of solar energetic particles, a picture that should become clear with future PSP orbits.