By‐dependent prompt penetrating electric fields at the magnetic equator

Abstract

We propose a new type of prompt penetrating electric field effect which seems to be related to the y‐component of the interplanetary magnetic field and the NBZ current system. We report an equatorial electric field pattern which is not consistent with present understanding of prompt penetrating electric fields. The associated unbalanced excess NBZ current in one hemisphere partially flows across the nighttime equatorial zone. We find that a current system closes perpendicular to the ecliptic plane in the solar wind with a direction opposite to the interplanetary electric field. This is required for an MHD generator located in the solar wind.