Transition region, corona, and solar wind in coronal holes: Some two-fluid models
Abstract
We consider the possibility that the heating of the corona and the heating and acceleration of the solar wind can be described by a single process, namely, the turbulent dissipation of solar-generated Alfven waves at the Kolmogorov rate. The model assumes that Te=Tp in r<=2 RS but drops electron-proton coupling in r>2 Rs. The dissipated wave energy is assumed to heat only the protons. Classical heat conduction is used in r>10 RS, and an electron polytrope is used in r>10 RS. The models have the right qualitative features: a steep temperature rise to T>106 K and acceleration to supersonic speeds. But models with base pressures neT>2×1014 (cgs) are too slow: v(1 AU)<280 kms-1. Models with v(1 AU)>400 kms-1 have lower base pressures: 1014<neT<2×1014 (cgs). A difficulty with the model is that line-of-sight proton random velocities (thermal plus wave) are larger than values deduced from Lyman α resonant scattering observations in 1.5<=r/RS<=4, and they do not fall off with r to the extent observed. Large random velocities are due in part to a proton temperature peak at r~3-4 Rs. On the whole, this model seems unsatisfactory, but several possible resolutions are discussed.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- September 1988
- DOI:
- 10.1029/JA093iA09p09547
- Bibcode:
- 1988JGR....93.9547H
- Keywords:
-
- Coronal Holes;
- Magnetohydrodynamic Waves;
- Plasma Heating;
- Solar Wind;
- Two Fluid Models;
- Wave Attenuation;
- Energy Dissipation;
- Particle Acceleration;
- Plasma Turbulence;
- Stellar Models;
- Interplanetary Physics: Sources of the solar wind;
- Interplanetary Physics: MHD waves and turbulence;
- Solar Physics;
- Astrophysics;
- and Astronomy: Corona;
- Interplanetary Physics: Solar wind plasma