ENERGETIC PARTICLES AT HIGH-LATITUDES

We review work on diffusion coefficients of energetic particles with a n attempt to extract implications on their behaviour at high latitudes . In the ecliptic plane results from solar energetic particle propagat ion between the Sun and about 5 AU can be described by an effective ra dial mean free path lambda(<r>), which is approximately constant as a function of distance r. When particle propagation in three dimensions in the heliosphere is considered it is not sufficient to consider lamb da(<r>) only. Jovian electrons can be used as probes to determine the parameters of three-dimensional diffusion. In the polar regions diffus ion is dominated by its parallel component. Some predictions how lambd a(parallel to) should vary with latitude are discussed. For different choices of this variation we present expectations for intensity-time p rofiles of solar particle events during the Ulysses polar passages.