Quantitative forecast of relativistic electron flux at geosynchronous orbit based on low-energy electron flux

[1] A strong correlation between the behavior of low-energy (tens to hundreds of keV) and high-energy (>1 MeV) electron fluxes measured at geosynchronous orbit has been discussed, and this correlation is further enhanced when a time offset is taken into account. A model has been developed incorporating this delay time between similar features in lowand high-energy electron fluxes to forecast the logarithm of daily averaged, 1.1--1.5 MeV electron flux at geosynchronous orbit several days in advance. The model uses only the current and previous days’ daily averaged fluxes of lowand high-energy electrons as input. Parameters in the model are set by optimizing prediction efficiency (PE) for the years 1995--1996, and the optimized PE for these 2 years is 0.81. The model is run for more than one full solar cycle (1995--2006), and it consistently performs significantly better than a simple persistence model, where tomorrow’s forecasted flux is simply today’s value. Model results are also compared with an inward radial diffusion forecast model, in which the diffusion coefficient is a function of solar wind parameters. When the two models are combined, the resulting model performs better overall than each does individually.