Addressing the impact of solar modulation systematic uncertainties on cosmic-ray propagation models

While remarkable progress has been made to understand the propagation of cosmic rays, a variety of astrophysical uncertainties persists. At energies below about 20 GeV, the cosmic-ray flux is significantly modulated by solar activity, a process that is not precisely understood. Using the recently published AMS-02 data for the time-dependent cosmic-ray fluxes, we study the effects of solar modulation using force-field and extended force-field models and derive improved cosmic-ray propagation models. We find that simple solar modulation models are likely to underestimate the complexity of comic-ray propagation in the solar system and present limitations in describing the time-dependent fluxes consistently.