Non-linear damping of visco-resistive Alfven waves in solar spicules

Interaction of Alfven waves with plasma inhomogeneities generates phase mixing which can lead to dissipate Alfven waves and to heat the solar plasma. Here we study the dissipation of Alfven waves by phase mixing due to viscosity and resistivity variations with height. We also consider nonlinear magnetohydrodynamic (MHD) equations in our theoretical model. Non-linear terms of MHD equations include perturbed velocity, magnetic field, and density. To investigate the damping of Alfven waves in a stratified atmosphere of solar spicules, we solve the non-linear MHD equations in the x-z plane. Our simulations show that the damping is enhanced due to viscosity and resistivity gradients. Moreover, energy variations is influenced due to nonlinear terms in MHD equations.Comment: Accepted for publication in Astrophysics and Space Science Journal. arXiv admin note: substantial text overlap with arXiv:1304.776