Monday

Energetic ions and electrons, accelerated during flares and at Coronal Mass Ejection driven shocks, may be detected by spacecraft instrumentation at various locations within the heliosphere. Such Solar Energetic Particle (SEP) measurements can be used to obtain information about the associated energy release processes at or near the Sun. Traditional interpretations of SEP data rely on assuming that heliospheric propagation can be described by kinetic equations that retain a single spatial variable, the distance travelled along a Parker spiral magnetic field line. In this presentation we show how two key processes taking place in interplanetary space make the classical 1D approximation invalid, so that a 3D modelling approach is required. The first is drift associated with curvature and gradient of the interplanetary magnetic field, and with the heliospheric current sheet. The second is meandering of magnetic field lines caused by turbulence. We model the former by means of a test particle code and the latter through a kinetic approach. We discuss implications for interpretation of SEP data.