Heliospheric terminal shock acceleration and modulation of the anomalous cosmic-ray component

It is shown that a non-drift, spherically-symmetric, terminal shock acceleration model gives reasonable fits to the observed anomalous oxygen spectra for 1976 and 1982 only when a compression ratio of 2 is used together with a moderate radial dependence for K_rr. Preliminary results with an axially-symmetric, terminal shock acceleration model, including drifts, show that despite a change in polarity the accelerated spectra, at 50 AU in the equatorial plane, differ negligibly. However, the calculated modulation of anomalous oxygen at 2 AU is significantly less for a qA < 0 epoch (1987) than when qA > 0 (1976).