Auroral luminosity and absorption of cosmic radio noise

Abstract

Riometer measurements of absorption of 27.6 MHz radio waves and simultaneous measurements of the auroral intensity in the zenith have been compared. There is a reasonably good correlation between the two sets of observations. There appears to be a time delay between outbursts of aurora and the increase in absorption. This time delay is usually a few minutes, in good agreement with current information on the recombination coefficients and electron densities. Occasionally the time delay is very short (less than 1 min). This appears to be associated with short bursts of strong aurora.