Night-time ionospheric currents

During night-time the electron density in the ionosphere is significantly reduced. As a consequence of this, it is expected that most of the currents in the ionosphere should die out. The validity of this assumption has been checked by scanning the literature for reports on current observations on the night side. The search was focused on events during magnetically quiet times as defined by the K-p index. Nighttime current observations have been published from high, middle and low latitudes. These findings demand a reconsideration of the term 'magnetically quiet condition' for field modeling purposes.