Long-term persistence of solar activity
Abstract
We examine the question of whether or not the non-periodic variations in solar activity are caused by a white-noise, random process. The Hurst exponent, which characterizes the persistence of a time series, is evaluated for the series of14C data for the time interval from about 6000 BC to 1950 AD. We find a constant Hurst exponent, suggesting that solar activity in the frequency range from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate,H ≈ 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process and that it is the same type of process over a wide range of time interval lengths.
- Publication:
-
Solar Physics
- Pub Date:
- February 1994
- DOI:
- 10.1007/BF00690625
- Bibcode:
- 1994SoPh..149..395R
- Keywords:
-
- Brownian Movements;
- Carbon 14;
- Dendrochronology;
- Maximum Entropy Method;
- Random Processes;
- Solar Activity;
- Sunspot Cycle;
- Time Series Analysis;
- White Noise;
- Annual Variations;
- Irradiance;
- Statistical Correlation;
- Strange Attractors;
- Solar Physics;
- Time Series;
- Solar Activity;
- Random Process;
- Periodic Variation;
- Interval Length