The Southern Auroral Zone as Defined by the Position of Homogeneous Arcs

Abstract

Observations on homogeneous arcs (H.A.) made at Macquarie Island (geomagnetic coordinates 60·7 °S., 243·1 °E.) are examined. The latitude of H.A. is found to be significantly dependent on the geomagnetic planetary disturbance index Kp and the time of day. For given values of Kp and time the probability distribution of latitude of H.A. has a sharply defined mode about 0.5° north of the mean.