Distribution of solar energetic particles in 3-dimensional coronal and interplanetary magnetic fields

Wednesday, 16 December 2015: 11:35
2009 (Moscone West)
Ming Zhang, Florida Institute of Technology, Melbourne, FL, United States and Tilaye Tadesse Asfaw, NASA Goddard Space Flight Center, Greenbelt, MD, United States
Solar energetic particles (SEPs) are produced either in solar flares or by coronal mass ejection (CME) shocks. While a strong CME shock can be large enough to cover a significant fraction of the solar surface, a typical solar flare must be very narrow. Many SEP events with the impulsive flare signature of an enhanced He3/He4 ratio can be seen simultaneously by several spacecraft located over a wide range of longitudes and latitudes. Also, as indicated by EUV waves appearing on the solar surface, CME shock waves expand at a finite speed in the corona. All these suggest that SEP source is not uniformly injected and distributed on the sun. However, SEP often can reach a nearly uniform distribution known as SEP reservoir throughout the inner heliosphere within less than a few days. To understand these, we use our 3-d model of SEP coronal and interplanetary propagation including perpendicular diffusion to investigate the behavior of SEP intensity and anisotropy seen at 1 AU. We examine how various possible scenarios of magnetic connections to a CME or flare site and particle injection profiles on the sun might affect the results.