LAUSR

The self-interaction of the Alfven wave associated with the parametric interaction between the Alfven wave and longitudinal plasma motion induced by this Alfven wave is investigated in a dissipative plasma with a thermal misbalance. The thermal misbalance caused by plasma heating and radiation cooling leads to changes in the steepening rate and the resulting amplitude of Alfven waves. The characteristic times of steepening and changes of amplitude are obtained analytically and subsequently calculated for the initial stage of self-interaction of sinusoidal Alfven waves applying the upper chromosphere and coronal hole conditions. Comparison with characteristic times of viscous and Ohmic dissipation is conducted as well. It is revealed that for the chromosphere conditions there are temperature ranges where Alfven waves can steepen faster and, therefore, the nonlinear Alfven dissipation observed by Grant et al. (Nat. Phys. 14(5), 480, 2018) could be stronger. Moreover, depending on the temperature range, the steepening of the wave can occur both in front and behind. In addition, temperature ranges were found in which the Alfven wave can be strongly absorbed due to the thermal misbalance. It should be mentioned that regions of fast steepening and fast damping due to the thermal misbalance intersect. Therefore, in these regions, the damping of Alfven waves can be most significant. We also show that for coronal hole conditions the thermal misbalance only affects the Alfven wave steepening.