Elemental Abundances of Energetic Particles within Magnetic Clouds Detected by Ulysses

Abstract

The study of particles from the solar wind thermal population up to higher near-relativistic energies provides a tool to analyze and characterize the internal structure of magnetic clouds (MCs). In this work, we analyze the elemental composition of energetic particles at ~1 MeV nucleon^-1. Statistically, using a data set of 40 MCs, we find that the relative abundances of the particles inside magnetic clouds are consistent with those found for gradual solar energetic particle events (SEPs). However, there are isolated cases in which flare particles are detected. We present one example of a MC, observed by Ulysses in 2001, that shows characteristics of flare-accelerated energetic particles and signs of flare interaction in the charge state distributions of solar wind ions.