Excitation of ion-acoustic waves by non-linear finite-amplitude standing Alfvén waves

We investigate, using a multi-fluid approach, the main properties of standing ion-acoustic modes driven by nonlinear Alfv\'en waves. The character Alfv\'enic pump is because we study superposition two identical circularly polarised counter-propagating consider parallel propagation along constant magnetic field and find that left right-handed generate via ponderomotive forces second harmonic demonstrate parametric instabilities are not relevant in present problem secondary waves attenuate Landau damping absence any other dissipative process. Kinetic effects included our model where ions considered as particles electrons massless fluid, hybrid simulations used to complement theoretical results. Analytical expressions obtained for time evolution different physical variables damping. From attenuation generated follows predictions even under presence driver pump. Due induced system develops density cavities an electric field. Theoretical this fluctuations derived. implications these results context slow mode oscillations coronal loops discussed.