Model of energy spectrum parameters of ground level enhancement events in solar cycle 23

TL;DR

This paper develops a model for the energy spectrum parameters of ground level enhancement events during solar cycle 23, based on fitting observational data and classifying events by solar conditions, aiming to improve future predictions.

Contribution

It introduces a novel model that predicts energy spectrum parameters of GLEs based on solar event conditions, differentiating between events with and without strong interplanetary shock acceleration.

Findings

Model accurately fits GLE energy spectra using double power-law parameters.

Distinct parameter models for GLEs with and without strong IP shock acceleration.

Potential application in forecasting future GLE events.

Abstract

Mewaldt et al. 2012 fitted the observations of the ground level enhancement (GLE) events during solar cycle 23 to the double power-law equation to obtain the four energy spectra parameters, the normalization parameter $C$, low-energy power-law slope $\gamma_1$, high-energy power-law slope $\gamma_2$, and break energy $E_0$. There are 16 GLEs from which we select $13$ for study by excluding some events with complicated situation. We analyze the four parameters with conditions of the corresponding solar events. According to solar event conditions we divide the GLEs into two groups, one with strong acceleration by interplanetary (IP) shocks and another one without strong acceleration. By fitting the four parameters with solar event conditions we obtain models of the parameters for the two groups of GLEs separately. Therefore, we establish a model of energy spectrum of solar cycle 23 GLEs which may be used in prediction in the future.