On the Claimed 5.5-year Periodicity in Solar Activity
Abstract
Recently, Djurovic and Pâquet (1996) claimed to have found an oscillation with a period of about 5.5 years in several solar and solar-terrestrial parameters, in particular in solar activity as indicated by sunspot numbers. Since the temporal evolution of the solar activity and solar-terrestrial environment is of great interest in many fields, we have examined their claim in detail. We show here that their conclusion is based on an artefact due a questionable method applied, and due to the asymmetric form of the solar cycle. Accordingly, there is no reasonable evidence for the existence of a fundamental 5.5-year periodicity in solar activity.
- Publication:
-
Solar Physics
- Pub Date:
- November 1997
- DOI:
- 10.1023/A:1004982203293
- Bibcode:
- 1997SoPh..176..201M
- Keywords:
-
- Solar Activity;
- Temporal Evolution;
- Solar Cycle;
- Sunspot Number;
- Reasonable Evidence