Particle transport in the solar wind

Energetic Particles in the inner heliosphere are accelerated at a variety sources such as Co-rotating Interaction Regions (CIRs), flares and CME-driven shocks. They propagate to 1 AU along interplanetary magnetic field, experiencing scattering by turbulent magnetic field along their way. Recently Ulysses observations of these high energy particles in the high latitudes showed that the interplanetary field are likely non-Parker or else strong cross field diffusion must be present. Concerning non-Parker field, there have been many attempts to introduce new models for interplanetary magnetic field that extend to high latitudes. Since the magnetic field lines are shaped by the footpoint motion in the photosphere which is not static and there are many different surface flows, footpoints can undergo random walk and cause the meandering of the field lines. Indeed, it is believed that because granules and supergranules have short lifetime, the position of the new born granules or supergranules cause the random walk of the footpoints which in turn leads to field meandering that make the fields access different latitudes. In this study, we consider realistic field lines that are caused by the random walk of the footpoints and follow the trajectories of test particles and drifts from the initial Parker line for different latitudes and different surface flow parameters. Our goal is to examine to what extend can the field line meandering be responsible for the latitudinal spreading of SEPs in, e.g., impulsive SEP events.