Abstract. The suprathermal particles, electrons and protons, coming from the Sun and precipitating into the high-latitude atmosphere are an energy source for the Earth's ionosphere. They interact with the ambient thermal gas through inelastic and elastic collisions. Most of the physical quantities perturbed by the precipitation, such as the electron production rate, may be evaluated by solving the stationary Boltzmann transport equation, which yields the particle fluxes as a function of altitude, energy, and pitch angle. This equation has been solved for the three different suprathermal species (electrons, protons and hydrogen atoms). We first compare the results of our theoretical code to a coordinated DMSP/EISCAT experiment, and to another approach. Then, we show the effects that pure proton precipitation may have on the ionosphere, through primary and secondary ionization. Finally, we compare the effects of proton precipitation and electron precipitation in some selected cases above EISCAT (Tromsø) and ESR.

Key words. Ionosphere (auroral ionosphere; ionosphere-magnetosphere interactions; particle precipitation).