The relation of the cusp precipitating electron flux to the solar wind and interplanetary magnetic field

Abstract

The temporal variation of the precipitating electron flux in the 47‐eV to 1‐keV energy range, detected in the low‐altitude cusp, is studied as a function of the solar‐wind parameters and the Bz component of the interplanetary magnetic field (IMF). It is found that the electron flux intensity in the polar cusp region depends nonlinearly on the density of the solar‐wind plasma and that it is higher in the negative IMF Bz period than in the positive IMF Bz period. Both these facts are consistent with the predictions of the existing models of magnetic field‐line merging at the magnetopause; however, the possibility that non‐linear diffusion processes predominate cannot be eliminated.