Physical Mechanisms of Solar Irradiance and Luminosity Variations
Abstract
The solar irradiance and luminosity changes observed over the last two decades measure distinct physical mechanisms, each triggered differently by solar magnetic fields. The irradiance fluctuations, associated with sunspots and bright faculae, are more aptly described as extremes from a range of magnetic perturbations which includes the magnetic network. We use accurate photometry from the ground and space to illustrate this and to show how proxy measurements using CaII K or magnetic flux density data can go awry while trying to identify the mechanisms of solar variability. Very precise, spatially resolved, solar surface brightness observations are a critical tool for understanding stellar convection, and in particular how the base of the convection zone evolves with the solar magnetic cycle. It is likely that our understanding and ability to predict the importance of solar irradiance variations, for example, for the terrestrial climate system, will depend on future surface brightness data of similar and improved accuracy.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2001
- Bibcode:
- 2001AGUSM..SP31B05K
- Keywords:
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- 1650 Solar variability;
- 7536 Solar activity cycle (2162);
- 7537 Solar and stellar variability;
- 7538 Solar irradiance