Some Comments on the Limb Shift of Solar Lines - Part Three - Variation of Limb Shift with Solar Latitude across Plages and across Supergranules
Abstract
We searched for a variation with heliographic latitude of the solar limb effect by comparing the relative wavelengths of weak and strong Fraunhofer lines. The blue shifts associated with the limb effect appear 9%±5% larger in the polar radius vector than in an equatorial radius vector at cos θ = 0.5. This should perhaps be interpreted as an increase with latitude of either solar convection or of convective overshoot. Recent observations of poleward meridional flows of 30m s−1 should be corrected for this limb effect variation. This correction increases this flow velocity to ∼70 m s−1. A search for a similar variation in plages and in network boundaries had negative results, the variation being +1%±5% and -1%±6% respectively.
- Publication:
-
Solar Physics
- Pub Date:
- November 1980
- DOI:
- 10.1007/BF00153265
- Bibcode:
- 1980SoPh...68...41B
- Keywords:
-
- Fraunhofer Lines;
- Photosphere;
- Solar Granulation;
- Solar Limb;
- Solar Spectra;
- Spectroheliographs;
- Convective Flow;
- Meridional Flow;
- Solar Atmosphere;
- Solar Physics;
- Spectrum Analysis;
- Solar Physics;
- Convection;
- Blue Shift;
- Effect Variation;
- Similar Variation;
- Recent Observation