Medium-Term Oscillations of the Solar Activity
Abstract
Besides the well-known 11-year cycle, longer and shorter characteristic periods can be isolated in variations of the parameters of helio-geophysical activity. In geomagnetic variations, one can also isolate oscillations with characteristic periods of 5-6 years (QSO) and 2-3 years (QBO). Periods of ~36 and ~60 years were revealed in geomagnetic activity variations and a ~60-year periodicity, in correlation between the pressure in the lower atmosphere and the solar activity. We have considered 5-6-year periodicities observed in variations of the sunspot numbers and the intensity of the dipole component of the solar magnetic field. Comparison with different magnetic dynamo models allowed us to conjecture the origin of these oscillations. As a result of the study, we conclude that the 5-6-year activity variations are related to the processes of nonlinear saturation of the dynamo in the solar interior. Quasi-biennial oscillations are actually separate pulses related little to each other. Therefore, the methods of the spectral analysis do not reveal them over large time intervals. They are a direct product of local fields, are generated in near-surface layers, and are reliably recorded only in the epochs of high solar activity.
- Publication:
-
Thirteenth Workshop on Solar Influences on the Magnetosphere, Ionosphere and Atmosphere
- Pub Date:
- September 2021
- DOI:
- 10.31401/WS.2021.proc
- Bibcode:
- 2021simi.conf...66O