Effects of various dissipation range onset models on the 26-day variations of low-energy galactic cosmic-ray electrons Original Research Article

The effect of various models presented by for the dissipation range cutoff wavenumber on the 26-day variations of galactic cosmic-ray electrons in a Fisk-Parker hybrid field is investigated, by means of a three-dimensional steady-state numerical modulation code. Analytical expressions for the mean free paths parallel and perpendicular to the heliospheric magnetic field are adapted from the works of , respectively. Note that only solar minimum conditions are considered, and that only qualitative agreement with data is sought. Effective diffusion for galactic electrons pertaining to 26-day variations is found to be dominated by the ratio of the perpendicular to parallel mean free paths at low energies, and the relationship between changes in cosmic-ray intensities and the modulation parameter postulated by is found to no longer hold when this ratio drops below a critical value. Use of ion inertial scale dependent models for the dissipation range cutoff leads to possible second linearities in the relative amplitudes as functions of latitude gradient.