Study of interaction between acoustic-Alfven waves in solar magnetic flux tubes

Solar acoustic oscillations are actually the same 5 minute oscillations that appear in the photosphere. These oscillations appear to be unable to penetrate into the solar corona due to the acoustic cut off of stratified atmosphere and the sharp temperature gradient in the transition region. The 5 minute acoustic oscillations may resonantly convert into Alfven waves in the region of the solar atmosphere. By perturbing the equilibrium state of the magnetised plasma, we showed that the acoustic and Alfven waves can interact through the nonlinear terms of the ideal MHD equations. We found that Alfven waves with twice the period of acoustic waves may propagate to upper layers when the speeds of sound and Alfven waves are equal, . This condition is obtained when, .