We present the first global simulations of the modulation of galactic cosmic rays by a three‐dimensional solar wind with corotating interaction regions. The cosmic‐ray transport equation is solved in a computed wind and magnetic‐field model. The results show both the previously‐neglected small‐scale response to CIR's and global, drift‐dominated, effects which are similar to previous models. Our model predicts a correlation between the local magnetic field and the rate of decrease of the cosmic‐ray intensity which is similar to that observed. This is found to be due to inhibited diffusion. We suggest that such small‐scale variations are local and that they do not change significantly the global cosmic‐ray structure except, perhaps, near sunspot maximum.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)