Particle transport and acceleration at corotating interaction regions

Abstract

The transport and acceleration of energetic nuclei associated with corotating interaction regions is discussed with emphasis on its importance relative to global heliospheric phenomena such as anomalous cosmic rays, the distant heliosphere, and propagation to high latitudes. We will discuss aspects of particle acceleration at the forward and reverse shocks bounding CIRs which support the idea that accelerated pickup ions are important contributors to energetic ions in the heliosphere. We will outline our current understanding of the source of CIR-associated energetic nuclei based on multispacecraft observations of the spatial variation of low-energy cosmic rays, as well as that of freshly ionized pickup ions. We will also discuss the propagation of CIR-associated energetic particles to high heliographic latitudes. We will present a model of the interplanetary magnetic field and show results from a numerical simulation which suggest that particles undergo significant latitudinal diffusion.