Wave damping in Hall plasmas: Application to the solar wind

The present study focusses on the damping of nonlinear magnetoacoustic waves in Hall viscous plasmas. Special attention is paid to solitary waves and their effect in the solar wind. In particular, the plasma acceleration by an obliquely propagating soliton is investigated. The results show that the solitons originating from the nonlinear steepening of slow waves can accelerate the plasma; the fast sotitons obtained from fast waves can decelerate the plasma. For certain propagation angles, the solitons evolve into shock waves. The results are consistent with the observed non-thermal Doppler broadening of the ion emission line, observed by SoHO UVCS telescope in the acceleration region of the solar wind.