Solar energetic particle events in the heliosphere: event on 2013 April 11

Abstract

Particle radiation during large solar energetic particle (SEP) events may constitute a hazard for space missions. Interplanetary shock waves driven by coronal mass ejections are the largest SEP sources in the inner solar system. We focus on the study of the SEP event on 2013 April 11 by using in-situ particle and solar wind plasma measurements from the Solar Terrestrial Relations Observatory (STEREO) A and B and near-Earth spacecraft. Using the Velocity Dispersion Analysis (VDA) method we estimated the release time of the particles, allowing us to identify the associated parent solar activity, and the distance traveled by the particles. In addition, we determined the energy spectra of the proton intensities at the shock crossing by Earth. Our results agree with predictions from theoretical models.