Strange currents over Saint‐Santin

Abstract

Analysis of 29 days of ionospheric current data obtained by Saint‐Santin radar, including both magnetically quiet and disturbed periods, has confirmed the existence of northward currents at all daytime hours. The postulate of field‐aligned Van Sabben currents driven by interhemispherical asymmetries seems to be able to account for the anomaly. The desirability of quantitative modeling of the Van Sabben currents on a seasonal or day‐to‐day basis is highlighted by the Saint‐Santin measurements.