COSMIC-RAY MODULATION AND A NONSPHERICAL HELIOSPHERIC SHOCK

The influence of a non-spherically symmetric heliospheric shock on the spatial distributions of galactic as well as anomalous cosmic rays in the heliosphere is investigated. The study uses a two-dimensional mod el and includes anisotropic diffusion and drift of the cosmic rays in the heliospheric magnetic field as well as a latitude-dependent solar wind flow. The model calculations are compared with observations made with the PIONEER and VOYAGER deep space probes. It is demonstrated tha t observations of latitudinal cosmic ray pressure gradients as the cur rent solar activity cycle advances towards a minimum around 1998 might provide us with information about a poleward extension of the heliosp heric shock.