Wave motions and wave heating in the upper solar atmosphere
Abstract
The experimental and theoretical evidence favoring the wave heating mechanism in the low chromosphere is briefly reviewed, and the possibility of maintaining this mechanism, with proper modifications, in the higher layer is studied. Wave mode candidates for heating at high levels are analyzed, including gravity waves and Alfven waves. Waves in the upper chromosphere and the transition region are considered, showing power spectra of oscillations in lines forming at increasing heights in the solar atmosphere, fluctuations in UV line intensity, the predicted relationship between velocity and intensity modulation for acoustic waves, and sample results from UV spectrometer and polarimeter observations. It is concluded that in the upper chromosphere and transition regions, observations fail to reveal an acoustic flux adequate to compensate for the energy losses in these layers. Alfven waves, observed in the solar wind, could supply the required energy flux, but their presence cannot either be confirmed or ruled out.
- Publication:
-
Memorie della Societa Astronomica Italiana
- Pub Date:
- 1982
- Bibcode:
- 1982MmSAI..53..411P
- Keywords:
-
- High Temperature Plasmas;
- Plasma Heating;
- Plasma Waves;
- Solar Atmosphere;
- Wave Propagation;
- Atmospheric Heating;
- Chromosphere;
- Gravity Waves;
- Ion Acoustic Waves;
- Magnetohydrodynamic Waves;
- Power Spectra;
- Propagation Modes;
- Solar Corona;
- Solar Temperature;
- Temperature Profiles;
- Solar Physics