Source Energy Spectrum of the 17 May 2012 GLE

Abstract

AbstractAmong the several GLEs (ground level enhancements) that have presumptuously occurred in the period 2012–2015, the 17 May 2012 is that which is more widely accepted to be a GLE, in view of the high number of high‐latitude neutron monitor stations that have registered it. In spite of the small amplitude, it was more prominent of the predicted GLE's of the present decade (Pérez‐Peraza & Juárez‐Zuñiga, 2015, https://doi.org/10.1088/0004-637X/803/1/27). However, the lack of latitude effect makes it difficult to study the characteristics of this event in the high‐energy extreme of the spectrum. Nevertheless, several outstanding works have been able to derive observational spectra at the top of the Earth atmosphere for this peculiar GLE. Some of these works find that the flow of protons is characterized by two components. Quite a great number of works have been published in relation with observational features obtained with different instrumentation, but the source phenomena, regarding the generation processes and source physical parameters, have not been scrutinized. The main goal of this work is to look at such aspects by means of the confrontation of the different approaches of the observational spectra with our analytical theoretical spectra based on stochastic acceleration and electric field acceleration from reconnection processes. In this way, we derive a set of parameters which characterize the sources of these two GLE components, leading us to propose possible scenarios for the generation of particles in this particular GLE event.