High-Latitude Irregularities during the Magnetic Storm of October 31 to November 1, 1972.

摘要

By using the scintillation of satellite radio beacons and radio stars as the means of determining the intensity of F layer irregularities, observations of the high-latitude irregularity region were made during the magnetic storm of October 31 to November 1, 1972. At ssc of this winter storm, the irregularity region from 60 deg to 63 deg invariant latitude was affected almost immediately. However, scintillation intensities were high only for a period of the order of many minutes and subsided again before the expansion phase of the storm. During the expansion phase the motion of the storm irregularities could be tracked equatorward particularly during the occurrence of one intense negative magnetic bay in the H component. The velocity was high at invariant latitudes of 53 deg -60 deg (of the order of 300-600 m/s) but slowed to 100-200 m/s from 49 deg to 53 deg and then to even lower velocities at 45 deg, the lowest latitude of the observations. A comparison with auroral photographs indicates that even 3 deg equatorward of the optical aurora the irregularity intensities at F layer heights were considerable. High levels of scintillation activity were also noted poleward of the aurora. Heat conduction due to auroral current energy dissipation or from isotropic electric fields is postulated as the source for the production of intense F layer irregularities during these severe magnetic storms. The precipitation of low-energy electrons is another (but less attractive) hypothesis. (Author)