Characteristics of Pg micropulsations at conjugate points

The Pg micropulsation is a unique 100-second sinusoidal oscillation that appears infrequently and only on the records of stations located near the auroral zone. Twenty such events were observed during 1963 and 1964 at the approximately conjugate observatories of College, Alaska, and Macquarie Island. Vector diagrams of the perturbation vector, power spectral density analysis of the events, and dispersion measurements of the wave form were used in this analysis. The characteristics of the Pg, as determined by these methods, are used to show that this type of micropulsation is produced by transverse hydromagnetic waves propagating along field lines to small, high-latitude, conjugate areas.