Solar mean magnetic field variability: A wavelet approach to Wilcox Solar Observatory and SOHO/Michelson Doppler Imager observations
Abstract
Solar mean magnetic field (SMMF) measurements from the Wilcox Solar Observatory and with the SOHO/MDI instrument are described and analyzed. Even though two completely different methods of observation are used, the two data sets obtained show a strong similarity. Using continuous wavelet transforms, SMMF variability is found at a number of temporal scales. Detected SMMF signals with a 1-2 year period are considered to be linked to variations in the internal rotation of the Sun. Intermediate SMMF oscillations with a period of 80-200 days are probably connected to the evolution of large active regions. We also find evidence for 90 min variations with coronal mass ejections as a suggested origin.
- Publication:
-
Journal of Geophysical Research (Space Physics)
- Pub Date:
- October 2002
- DOI:
- 10.1029/2001JA009195
- Bibcode:
- 2002JGRA..107.1318B
- Keywords:
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- Solar Physics;
- Astrophysics;
- and Astronomy: Solar activity cycle (2162);
- and Astronomy: Solar and stellar variability;
- and Astronomy: Instruments and techniques;
- and Astronomy: Magnetic fields;
- Solar magnetic field;
- wavelet analysis;
- internal rotation;
- active regions;
- coronal mass ejections