Compressive Instability Driven by Ion-Cyclotron Dissipation in the Solar Wind

Recent models of the heating and acceleration of the fast solar wind invoke the dissipation of relatively high-frequency waves by ion-cyclotron absorption. It is shown that modulations in the heating rate induced by compressive perturbations in the flow may drive the system unstable in the supersonic region. Therefore it is possible that density fluctuations generated by this instability and maintained at a level determined by the marginal stability condition are manifest in the wind.