Coronal loops heated by turbulence-driven Alfven waves

Li, Xing, Habbal, S. R., 'Coronal loops heated by turbulence-driven Alfven waves', The Astrophysical Journal, (2003) 598(2) pp.L125-L128 RAE2008

A two-fluid dynamic model of long-lived coronal loops is presented, whereby heating of the confined plasma is achieved by turbulence-driven Alfv?n waves. It is assumed that the nonthermal motions inferred from spectral line observations in the transition region are due to Alfv?n waves. It is also assumed that the turbulence is already fully developed when the waves are injected at the footpoint of the loop while the wave/turbulence energy is readily absorbed by the proton gas. The Coulomb coupling between protons and electrons subsequently heats the electron gas. The model produces a fairly uniform electron temperature in the coronal segment of the loop even though the heating is nonuniform. The model also reproduces electron densities of cm?3, in the range inferred from observations, as well as a moderate flow speed around 10 km s?1 along the loop. The turbulence heating mechanism adopted in this Letter, however, cannot produce stable loops with temperatures K.

Peer reviewed