Spectral Irradiance Variations and Magnetic Field Changes During Solar Cycle 23.
Abstract
Both total irradiance and the Mg core-to-wing ratio was high at the maximum of weak solar cycle 23. However, photometric observations from the San Fernando Observatory show that both the number and size of active regions (spots and faculae) were low at the maximum of solar cycle 23 which points to the importance of the role of weak magnetic fields in irradiance variations. The purpose of this paper is to use new SOLIS spectromagnetograph observations in conjunction with a newly developed image analysis technique to compare irradiance time series as function of wavelengths with various surface magnetic features. One major goal is to compare features derived from the SOLIS images using the new technique with well-established features from SFO. Another important goal is to determine the contribution of active regions/weak fields to irradiance variations at various wavelengths, using the SOHO/VIRGO and SORCE/SIM data. A third goal is to determine the extent of irradiance variations not explained by magnetic structures. To do this, we use a new analysis technique to evaluate SOLIS spectromagnetograph observations.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFMSH13A1504P
- Keywords:
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- 7524 Magnetic fields;
- 7529 Photosphere;
- 7536 Solar activity cycle (2162);
- 7538 Solar irradiance;
- 7594 Instruments and techniques