On the theoretically predicted flux profiles over polar caps and their comparison with observations

Abstract

A method for constructing theoretical latitudinal profiles of solar proton fluxes over polar caps is proposed. It is based on transfer functions between the interplanetarv medium and the detector in polar orbiting satellite and on information obtained from simulation of 2 to 500 MeV proton orbits in magnetospheric models. The method takes into account the dependence of flux profiles on local time of observation, on seasonal or storm changes in tail topology and on the whole spectrum of energies registered by detector's channel. Comparison with observations allow a more rigorous analysis than the one achieved by methods used in the past, permits a more detailed identification of regions of entry and an interpretation of some fine features of the observed flux structures.Theoretical profiles for higher energy channels constructed for th anisotropic phase of February 25, 1968 and November 18, 1969 events agree satisfactorily with the observations and with our model of uneven illumination and leads to postulate a turning mechanism that operates in the tail boundary region. For lower energies the comparison between predicted and observed structures indicates the influence of strong modulating mechanisms. The method when applied to a large number of selected observations in different energy channels allows an improved sensitivity of the technique of tracing the topology of the geomagnetic cavity and of its boundary region by means of solar protons.