Direct Evidence of Non-Ideal Dissipative Dynamics in Solar Wind Magnetic Switchbacks

TL;DR

This study uses Parker Solar Probe data to demonstrate that solar wind magnetic switchbacks are non-ideal Hall-MHD structures with active energy dissipation, resolving longstanding controversies about their physics and origin.

Contribution

The paper provides direct electric field measurements showing switchbacks are Hall-MHD structures with active evolution, challenging ideal MHD models and clarifying their solar wind origin.

Findings

Switchbacks have non-zero electric fields in the plasma frame.

Enhanced Poynting vectors exist only inside switchbacks.

Switchbacks are non-MHD, actively evolving structures.

Abstract

Magnetic switchbacks, large-amplitude, localized Alfvenic like rotations of the solar wind magnetic field, have been the subject of intensive investigation, with approximately 200 refereed papers published in the last decade. Yet, fundamental controversies persist regarding whether switchbacks can be described with Ideal MHD (magnetohydrodynamic) physics or Hall-MHD physics and whether their origin is at the solar surface or in the solar wind. To settle these controversies, we present Parker Solar Probe electric field measurements between 13 and 40 solar radii, which show that switchbacks have non-zero electric fields in the plasma frame, a finding that definitively settles the physics controversy by proving that switchbacks are Hall-MHD, not Ideal MHD, structures. Along with these electric fields, there are enhanced Poynting vectors having three components with similar magnitudes that exist only inside the switchbacks. These facts contradict the view of switchbacks as simple outward-propagating pulses. Together, they resolve one controversy by showing that switchbacks in the young solar wind are a non-MHD process. They contribute to the second (source) controversy by identifying switchbacks as sites of active, in-situ, evolution. These findings provide a new framework for understanding energy transport and dissipation in astrophysical plasmas.