| Abstract: | A physical model of the solar transition region and corona is presented, in which plasma flows in rapidly-diverging coronal
funnels and holes are described within the framework of a two-fluid model including wave-particle interactions. The ions are
heated by wave dissipation and accelerated by the pressure gradient of high-frequency Alfvén waves, which are assumed to originate
at the bottom of the magnetic network by small-scale reconnection. The heating is assumed to be due to cyclotron-resonant
damping of the waves near the local ion gyrofrequency. The EUV emission lines observed by the SUMER spectrometer on SOHO show
very strong broadenings, which seem to be ordered according to the ion charge-per-mass ratio and thus to indicate cyclotron-resonant
heating by waves. Based on quasilinear theory, a closure scheme for anisotropic multi-component fluid equations is developed
for the wave-particle interactions of the ions with Alfvén waves. The acceleration and heating rates are calculated.
This revised version was published online in July 2006 with corrections to the Cover Date. |
