Periodic fading in 42-MHz auroral backscatter

During April and May 1964, high-speed polarization measurements of 42-MHz auroral backscatter were made at Saskatoon with a time-sharing polarimeter capable of measuring fading rates up to about 100 Hz. The fading is often very deep and quasi-periodic with pronounced power in the 5–25 Hz range and major peaks near 10 Hz. The spectral power becomes greater in the 5–10 Hz range when the auroral scatter intensity increases. The relationship between the scatter bursts and pulsating primary electron flux is discussed.