Mid-latitude Pi 2 pulsations, geosynchronous substorm onset signatures and auroral zone currents on March 22, 1979: CDAW 6
We relate the mid‐latitude Pi 2 pulsation signatures observed using the Air Force Geophysics Laboratory Magnetometer Network during the March 22, 1979, Sixth Coordinated Data Analysis Workshop interval to the magnetic variations observed at geosynchronous orbit and to ionospheric current distributions derived from high latitude magnetometer data and an ionospheric conductivity model. We are able to show that at least three separate substorm onsets or intensifications occurred around 1100 UT, specifically at 1053:50, 1104:10 and 1110:30 UT. We contrast an earlier onset which occurred at 0614 UT during a geomagnetically quiet interval to these more disturbed events. In both cases the Pi 2 polarization pattern locates the region of strong westward electrojet. Changes in the Pi 2 polarization during a single event appear to accompany small shifts in the electrojet position. These events do not obey the Pi 2 period‐electrojet latitude relationship obtained by Kuwashima and Saito (1981).