Solar radio noise in the frequency range 1.5 to 10 MHz appears sporadically in the Alouette sweep-frequency recordings above the galactic noise level. The type III bursts can be readily identified, but other spectral types are much more difficult to identify from only the satellite records. Using a plausible model for the coronal electron densities, the Type III frequency drift curves have been interpreted as corresponding to a source velocity in the range 0.1 to 0.15 times the velocity of light. Preliminary estimates have also been made of the coronal temperatures from some of the burst durations.Other solar noise events of longer duration have not been classified other than as enhanced solar noise at this stage. These enhancements frequently show an intensity structure, extending down to the 1.5 MHz lower frequency limit of the equipment. These events are discussed briefly.
Solar noise observations from the Alouette satellite