Magnetic field line transport in the solar wind anisotropic turbulence

The transport of energetic particles in the heliosphere is strongly influenced by the magnetohydrodynamic turbulence found in the solar wind. The analysis of the variance matrix of the magnetic perturbations observed in the solar wind shows that magnetic turbulence can be well represented by anisotropic power law spectra for the Alfvenic and magnetosonic polarizations. The random walk of magnetic field lines is studied by means of a numerical realization of such turbulence, by varying the level of magnetic fluctuations and the degree of anisotropy. For high fluctuation levels, transport is faster in the direction where the correlation length is larger. In the solar wind, the largest correlation length appears to be in the direction normal to the B(IMF)-V(SW) plane, thus allowing fast latitudinal transport. The implications for energetic particle transport are discussed and compared to the observation of energetic particle events at high solar latitudes by the Ulysses spacecraft.