English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Braginskii MHD provides a more accurate description of many plasmaenvironments than classical MHD since it actively treats the stress tensorusing a closure derived from physical principles. Stress tensor effectsnonetheless remain relatively unexplored for solar MHD phenomena, especially innonlinear regimes. This paper analytically examines nonlinear damping andlongitudinal flows of propagating shear Alfv\'en waves. Most previous studiesof MHD waves in Braginskii MHD considered the strict linear limit of vanishingwave perturbations. We show that those former linear results only apply toAlfv\'en wave amplitudes in the corona that are so small as to be of littleinterest, typically a wave energy less than $10^{-11}$ times the energy of thebackground magnetic field. For observed wave amplitudes, the Braginskii viscousdissipation of coronal Alfv\'en waves is nonlinear and a factor around $10^9$stronger than predicted by the linear theory. Furthermore, the dominant dampingoccurs through the parallel viscosity coefficient $\eta_0$, rather than theperpendicular viscosity coefficient $\eta_2$ in the linearized solution. Thispaper develops the nonlinear theory, showing that the wave energy densitydecays with an envelope $(1+z/L_d)^{-1}$. The damping length $L_d$ exhibits anoptimal damping solution, beyond which greater viscosity leads to lowerdissipation as the viscous forces self-organise the longitudinal flow tosuppress damping. Although the nonlinear damping greatly exceeds the lineardamping, it remains negligible for many coronal applications.

Nonlinear Damping and Field-aligned Flows of Propagating Shear Alfv\'en Waves with Braginskii Viscosity