Work

Driven Phase-mixed Alfvén Waves in a Partially Ionized Solar Plasma

Year: 2025

Type: article

Abstract: Phase mixing has long been understood to be a viable mechanism for expediting the dissipation of Alfvén wave energy resulting in the subsequent heating of the solar atmosphere. To fulfill the conditions necessary for phase mixing to occur, we consider the cross-field gradient in the Alfvén speed as a free parameter in our model. Using a single-fluid description of a partially ionized chromospheric plasma, we explore the efficiency of damping of shear Alfvén waves subject to phase mixing when a pulse wave driver is employed. Our results demonstrate a strong dependence of the dissipation length of shear Alfvén waves on both the ionization degree of the plasma and the gradient of the Alfvén speed. When assessing the efficiency of phase mixing across various inhomogeneities, our findings indicate that waves originating from a pulse driver initially exhibit heating rates identical to those generated by a continuous wave driver. One key difference observed was that Alfvén pulses possess a lower overall decay rate, due to a change in damping profile from exponential to algebraic. This discrepancy arises from the absence of a consistent injection of energy into the base of the domain, which preserves longitudinal gradients of the magnetic field perturbations more effectively. These findings demonstrate the importance of understanding the relations between the wave driver, damping mechanisms, and propagation dynamics in resolving the atmospheric heating problem.

Source: The Astrophysical Journal

DOI: 10.3847/1538-4357/ade303

Authors: M. McMurdo, I. Ballai, G. Verth, V. Fedun

Institutions: KU Leuven, University of Sheffield

Language: English

Topic: Solar and Space Plasma Dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $4,499