Observations of Pi 2 pulsations occurring on December 24, 1971, and January 4, 1972


  • Richard R. Heacock


High latitude observations are provided to supplement those given by Lanzerotti et al. [1976] in comparisons between ground sites and the S³-A satellite. Pi 2 spectra for College, Alaska, correlate well with S³ spectra for these events. Amplitudes at S³ were an order of magnitude smaller than at the feet of the S³ field lines, consistent with an odd-mode wave null near to the equator. Evidence is given for the existence of pulsations of local (ionospheric) origin on the Great Whale River records for January 4, 1972. The Pi 2 pulsations of December 24, 1971, were observed at the pole sites, Thule and Vostok, with amplitudes on the same order as at middle latitudes.