ИСТИНА

Low-altitude fluxes are known to be dependent on solar activity levels due to the resulting heating and cooling of the upper atmosphere. However, variation of the trapped proton fluxes with the solar activity still cannot be accurately predicted. The AP8 model widely used for the practical purposes exists only in two variants for solar maximum and solar minimum. Nowadays there are an attempts to create new models (empirical, semi –empirical and theoretical) that are dependent on a solar activity. But despite on a significant progress in this work investigation of trapped proton fluxes measured on board modern satellites is still actual for the improvement of the existing models. In this work we analyze the equatorial proton flux with energy over the 70 MeV on L-shells less then 1.2 measured on board NPOES-15 satellite during the 23d solar cycle. These data were compared with the experimental data obtained in 21st and 22d solar cycles.