Models of solar energetic particle fluxes: The main requirements and the development prospects

The models of solar energetic particles (SEP) are intended for calculating the proton fluences and peak fluxes, which are expected to occur for a given period at any known or predicted solar activity level and to exceed their calculated sizes within a given probability. Any SEP model should reflect the objective reality, including the regular features inherent to the particles. The requirements are formulated, which have to be met by the present-day models aimed at predicting the SEP fluxes in the spacecraft trajectories as accurately as possible. Particular attention is paid to analyzing the factors that cause the most frequent deficiencies of the present-day solar energetic particle flux models.