Influence of the definition of dissipative events on their statistics

Abstract

A convenient and widely used way to study the turbulent plasma in the solar corona is to do statistics of properties of events (or structures), associated with flares, that can be found in observations or in numerical simulations. Numerous papers have followed such a methodology, using different definitions of an event, but the reasons behind the choice of a particular definition (and not another one) is very rarely discussed. We give here a comprehensive set of possible event definitions starting from a one-dimensional data set such as a time-series of energy dissipation. Each definition is then applied to a time-series of energy dissipation issued from simulations of a shell-model of magnetohydrodynamic turbulence as defined in Giuliani and Carbone (1998), or from a new model of coupled shell-models designed to represent a magnetic loop in the solar corona. We obtain distributions of the peak dissipation power, total energy, duration and waiting-time associated to each definition. These distributions are then investigated and compared, and the influence of the definition of an event on statistics is discussed. In particular, power-law distributions are more likely to appear when using a threshold. The sensitivity of the distributions to the definition of an event seems also to be weaker for events found in a highly intermittent time series. Some implications on statistical results obtained from observations are discussed.

arXiv comment8 pages, 13 figures. Submitted to Astronomy&Astrophysics

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Cited by in corpus (12)

• 25 Years of Self-Organized Criticality: Solar and Astrophysics
• Shell Models of Magnetohydrodynamic Turbulence
• Reconciliation of Waiting Time Statistics of Solar Flares Observed in Hard X-Rays
• Shell-models of RMHD turbulence and the heating of solar coronal loops
• 25 Years of Self-Organized Criticality: Numerical Detection Methods
• Stochastic coupling of solar photosphere and corona
• Energetic characterisation and statistics of solar coronal brightenings
• The Energetics of a Flaring Solar Active Region, and Observed Flare Statistics
• Evidence for departure from a power-law flare size distribution for a small solar active region
• Effects of flare definitions on the statistics of derived flare distributions
• Energy Balance in Avalanche Models for Solar Flares
• Monte-Carlo Simulation of Solar Active-Region Energy