Wave dissipation by ion cyclotron resonance in the solar corona

It has recently been suggested that small-scale reconnection occurring in t he chromospheric network creates high-frequency Alfven waves, and that thes e waves may represent the main energy source for the heating of the solar c orona and generation of the solar wind. However, if these waves exist, they will be absorbed preferentially by the minor heavy ions with low gyrofrequ encies, and thus it is unclear whether there is actually enough wave energy left over for the heating and acceleration of the major solar wind ions, n amely protons and alpha particles, in the extended corona after the absorpt ion by heavy ions (Cranmer 2000). We have studied this problem with the mul ti-fluid model presented by Tu & Marsch (2001), which includes the self-con sistent treatment of the damping of the waves as well as the associated acc eleration and heating of the ions. We found that if the wave power density is sufficiently large, say about 1000 nT(2) Hz(-1) at 160 Hz and 2.5 R-circ le dot, then the wave absorption by a prominent minor ion such as O+5 is sm all, and most of the wave energy is left for absorption by protons. This oc curs because the minor ions are quickly (within several gyroperiods) accele rated and then are induced to partially surfing the waves. However, if the wave power is too low, say lower than 10 nT(2) Hz(-1) at 160 Hz and 2.5 R-c ircle dot, then the damping of the wave power by the O+5 ions is severe, an d little wave energy is left for protons.