Magnetic field line transport in the heliosphere and energetic particle propagation from corotating interaction regions to high heliographic latitudes

A numerical model of magnetic turbulence allows us to compute the diffusion coefficients for different degrees of anisotropy, and in particular for th e cases corresponding to the solar wind. We consider here the problem of th e propagation of the energetic particles accelerated by corotating interact ion regions (CIRs) and observed by Ulysses at high heliographic latitudes. The excursion in latitude of a magnetic field line located at large heliosp heric distance is evaluated with a Monte Carlo simulation. In the calculati ons, the random `force' terms are proportional to the square root of the di ffusion coefficient in each direction. By tracing a large number of field l ines, we can devise how the particles would be seen by Ulysses. Good agreem ent with the actual observations is found.