Intensity Thresholds and the Statistics of the Temporal Occurrence of Solar Flares

TL;DR

This paper introduces a threshold-based method to analyze solar flare time series, revealing scale-invariant distributions of flare intervals that depend on the solar cycle phase, providing new insights into flare statistics.

Contribution

It presents a novel threshold-based approach to define and analyze solar flare events and their interoccurrence times, uncovering universal scaling behaviors.

Findings

Waiting and quiet time distributions follow universal scaling functions.

Scaling parameters vary with the solar cycle phase.

Standard flare definitions exhibit similar statistical behavior.

Abstract

Introducing thresholds to analyze time series of emission from the Sun enables a new and simple definition of solar flare events, and their interoccurrence times. Rescaling time by the rate of events, the waiting and quiet time distributions both conform to scaling functions that are independent of the intensity threshold over a wide range. The scaling functions are well described by a two parameter function, with parameters that depend on the phase of the solar cycle. For flares identified according to the current, standard definition, similar behavior is found.