Anomalous cosmic ray spectra, observed by Voyager 1 at the solar wind terminatiuon shock crossing, were not of the form expected of first order Fermi (or shock) acceleration, but gave an indication that they were modulated relative to that form. Further data analysis reveals two other remarkable features, namely that the energy where the peak ACR intensity occurs is about four times higher than it was during the previous solar minimum in 1997, and that regression plots of low versus high energy cosmic rays, both of the anomalous and galactic species, show little or no indication of the shock crossing. These phenomena are investigated in this paper with numerical solutions of the cosmic ray transport equation. The two main conclusions are that (a) the features of cosmic ray intensities that were observed during the shock crossing were dominated by temporal variations in the intensity as the heliosphere was resetting towards solar minimum conditions, and (b) the change in spectra with solar field reversal ar not yet understood.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 1 (SH), pages 847-850