Horizontal Velocities in the Solar Photosphere
Abstract
Horizontal macroscopic velocities Vhor in the photosphere are studied. High-resolution spectrograms of quiet regions are analyzed for center-limb variation of rms Doppler shifts. The data are treated to assure that the observed velocities refer to constant size volumes on the Sun (800 × × 3000 × 250 km), independent of μ. Using known height variation of vertical velocities and calculated line formation heights, the height dependence of «Vhor» is obtained. From a value around 450 m s−1 it decreases rapidly with increasing height. To study also small-scale velocities, the time evolution of subarcsecond size elements in the photospheric network (solar filigree) is studied on filtergrams. It is concluded that they show proper motions implying «Vhor» about 1 km s−1.
- Publication:
-
Solar Physics
- Pub Date:
- January 1975
- DOI:
- 10.1007/BF00183151
- Bibcode:
- 1975SoPh...40...53D
- Keywords:
-
- Doppler Effect;
- Flow Velocity;
- Line Spectra;
- Photosphere;
- Solar Atmosphere;
- Spectroheliographs;
- Atmospheric Models;
- Filtergrams;
- High Resolution;
- Radial Distribution;
- Solar Limb;
- Solar Spectra;
- Solar Physics;
- Assure;
- Time Evolution;
- Vertical Velocity;
- Horizontal Velocity;
- Size Element