Magnetospheric driving parameters to predict electron fluxes in the outer radiation belt

One of the most prominient features of the relativistic electron fluxes in the Earth's outer radiation belt is their large temporal variations. In order to define a simple model for the relativistic electron fluxes, the correlations between the flux and various geomagnetic and solar wind parameter have been studied for the case of the Strv-1b/REM measurements.

At L=4.5 the best correlation is found with Ap15 and at L=6.6 with Vsw3 (3-day averaged solar wind bulk velocity). Sophisticated functions of parameters including IMF, IMF orientation, or solar wind density do not increase the correlation. Improvements were obtained by introducing the linear combination of parameters and a correction based on Dst.

Data from CRRES/MEA have been used to build an Ap15-dependent model of the electron fluxes in the range of 47-2200 keV that can be used to extend the CRRESELE model. However a comparison with Strv-1b/REM data has shown that the parameter Ap15 is not enoughly efficient to characterize the state of the electron outer radiation belt over a whole solar cycle.