On the effects of ion-neutral interactions in solar plasmas

TL;DR

This paper reviews how ion-neutral interactions and non-ideal MHD effects influence the dynamics and energetics of the solar atmosphere, especially in the photosphere and chromosphere.

Contribution

It provides a comprehensive overview of multi-fluid MHD modeling approaches addressing ion-neutral interactions in the solar atmosphere.

Findings

Ion-neutral interactions significantly affect wave propagation and damping.

Non-ideal MHD effects influence magnetic reconnection and flux emergence.

Multi-fluid models improve understanding of solar atmospheric phenomena.

Abstract

Solar photosphere and chromosphere are composed of weakly ionized plasma for which collisional coupling decreases with height. This implies a breakdown of some hypotheses underlying magnetohydrodynamics at low altitudes and gives rise to non-ideal MHD effects such as ambipolar diffusion, Hall effect, etc. Recently, there has been progress in understanding the role of these effects for the dynamics and energetics of the solar atmosphere. There are evidences that such phenomena as wave propagation and damping, magnetic reconnection, formation of stable magnetic field concentrations, magnetic flux emergence, etc. can be affected. This paper reviews the current state-of-the-art of multi-fluid MHD modeling of the coupled solar atmosphere.