Energy Transfer by Nonlinear Alfv\'en Waves in the Solar Chromosphere, and Its Effect on Spicule Dynamics, Coronal Heating, and Solar Wind Acceleration

TL;DR

This study uses one-dimensional MHD simulations to explore how nonlinear Alfvén waves influence solar chromosphere dynamics, coronal heating, and solar wind acceleration, revealing that high nonlinearity limits energy transfer and affects solar atmospheric phenomena.

Contribution

It demonstrates how nonlinear Alfvén waves affect solar atmosphere dynamics and energy transfer, highlighting the role of wave nonlinearity in limiting coronal heating and solar wind acceleration.

Findings

High nonlinearity in Alfvén waves decouples chromospheric dynamics from photospheric energy input.

Strong shear flows in the chromosphere cause magnetic flux tube fractures and shock formations.

Nonlinear effects limit the transmission of Poynting flux into the corona.

Abstract

Alfv\'en waves are responsible for the transfer of magnetic energy in the magnetized plasma. They are involved in heating solar atmosphere and driving solar wind through various nonlinear processes. Since the magnetic field configurations directly affect the nonlinearity of Alfv\'en waves, it is important to investigate how they relate to the solar atmosphere and wind structure through the nonlinear propagation of Alfv\'en waves. In this study, we carried out the one-dimensional magnetohydrodynamic simulations to realize the above relation. The results show that when the nonlinearity of Alfv\'en waves in the chromosphere exceeds a critical value, the dynamics of the solar chromosphere (e.g., spicule) and the mass loss rate of solar wind tend to be independent of the energy input from the photosphere. In a situation where the Alfv\'en waves are highly nonlinear, the strong shear torsional flow generated in the chromosphere ``fractures'' the magnetic flux tube. This corresponds to the formation of chromospheric intermediate shocks, which limit the transmission of the Poynting flux into the corona by Alfv\'en waves and also inhibits the propagation of chromospheric slow shock.