The anisotropies of galactic cosmic rays: 3-dimensional modeling Original Research Article

We report on model calculations for the anisotropies of galactic cosmic rays at the orbit of the Earth. We consider the 5 – 25 GV range where the diffusion approximation is still applicable. The predicted ecliptic and North-South components of the anisotropy in various 2-dimensional (2-D) and 3-dimensional (3-D) models are discussed. Our 3-D numerical code, including large-scale particle drifts in a model heliosphere with a wavy current sheet and corotating interaction regions (CIRs), is extended to calculate anisotropies. Simulation results obtained for the two opposite magnetic cycles are presented for 3-D models with uniform solar wind speed as well as for those with CIRs included. Recurrent 27-day variations are discussed.