Preferential Proton over Electron heating from coherent structures during the first perihelion of Parker Solar Probe

TL;DR

This study uses Parker Solar Probe data to show that magnetic coherent structures in the solar wind preferentially heat protons over electrons, highlighting a turbulence-driven mechanism for solar wind heating.

Contribution

It provides the first observational evidence linking magnetic coherent structures to preferential proton heating in the early solar wind.

Findings

Regions with strong magnetic gradients show enhanced proton temperatures.

Electron temperatures are only slightly elevated in these regions.

Proton heating is driven by a nonlinear turbulent cascade.

Abstract

The solar wind undergoes significant heating as it propagates away from the Sun; the exact mechanisms responsible for this heating remain unclear. Using data from the first perihelion of the Parker Solar Probe mission, we examine the properties of proton and electron heating occurring within magnetic coherent structures identified by means of the Partial Variance of Increments (PVI) method. Statistically, regions of space with strong gradients in the magnetic field, $PVI \geq 1$, are associated with strongly enhanced proton but only slightly elevated electron temperatures. Our analysis indicates a heating mechanism in the nascent solar wind environment facilitated by a nonlinear turbulent cascade that preferentially heats protons over electrons.