Non-Stationary Fast-Driven Self-Organized Criticality in Solar Flares

Abstract

The original concept of self-organized criticality (Bak et al.~1987), applied to solar flare statistics (Lu and Hamilton 1991), assumed a slow-driven and stationary flaring rate, which warrants time scale separation (between flare durations and inter-flare waiting times), it reproduces power-law distributions for flare peak fluxes and durations, but predicts an exponential waiting time distribution. In contrast to these classical assumptions we observe: (i) multiple energy dissipation episodes during most flares, (ii) violation of the principle of time scale separation, (iii) a fast-driven and non-stationary flaring rate, (iv) a power law distribution for waiting times $\Delta t$, with a slope of ${\alpha }_{\Delta t}\approx 2.0$, as predicted from the universal reciprocality between mean flaring rates and mean waiting times; and (v) pulses with rise times and decay times of the dissipated magnetic free energy on time scales of $12\pm 6$ min, up to 13 times in long-duration ($\lapprox 4$ hrs) flares. These results are inconsistent with coronal long-term energy storage (Rosner and Vaiana 1978), but require photospheric-chromospheric current injections into the corona.

19 p, 8 Figs

References in corpus (11)

• Optimization code with weighting function for the reconstruction of coronal magnetic fields
• Preprocessing of vector magnetograph data for a non-linear force-free magnetic field reconstruction
• 25 Years of Self-Organized Criticality: Solar and Astrophysics
• Automated Solar Flare Statistics in Soft X-rays over 37 Years of GOES Observations - The Invariance of Self-Organized Criticality during Three Solar Cycles
• Global Energetics of Solar Flares: I. Magnetic Energies
• On the reliability of magnetic energy and helicity computations based on nonlinear force-free coronal magnetic field models
• The Energetics of a Flaring Solar Active Region, and Observed Flare Statistics
• Time-energy correlations in solar flare occurrence
• Global Energetics of Solar Flares. IX. Refined Magnetic Modeling
• Monte-Carlo Simulation of Solar Active-Region Energy
• Statistical Models for Solar Flare Interval Distribution in Individual Active Regions

Cited by in corpus (4)

• The Poissonian Origin of Power Laws in Solar Flare Waiting Time Distributions
• The Solar Memory From Hours to Decades
• Correlation of the sunspot number and the waiting time distribution of solar flares, coronal mass ejections, and solar wind switchback events observed with the Parker Solar Probe
• Role of the Solar Minimum in the Waiting Time Distribution Throughout the Heliosphere