ANOMALOUS COSMIC-RAYS AND SOLAR MODULATION

We review aspects of anomalous cosmic rays (ACRs) that bear on the sol ar modulation of energetic particles in the heliosphere. We show that the latitudinal and radial gradients of these particles exhibit a 22-y ear periodicity in concert with the reversal of the Sun's magnetic fie ld. The power-law index of the low energy portion of the energy spectr um of ACRs at the shock in 1996 appears to be less than or equal to -1 .3, suggesting that the strength of the solar wind termination shock a t the helioequatorial plane is relatively weak, with s less than or eq ual to 2.8. The rigidity dependence of the perpendicular interplanetar y mean free path in the outer heliosphere for particles with rigiditie s between similar to 0.2 and 0.7 GV varies approximately as R-2, where R is particle rigidity. There is evidence that ACR oxygen is primaril y multiply charged above similar to 20 MeV/nuc and primarily singly-ch arged below similar to 16 MeV/nuc. The location of the termination sho ck was at similar to 65 AU in 1987 and similar to 85 AU in 1994.