SABRE observations of a sequence of Pc 5 micropulsations


  • J. A. Waldock,

  • E. C. Thomas,

  • C. P. Stewart,

  • T. B. Jones,

  • E. Nielsen


Observations of a Pc 5 micropulsation event, using the Wick half of the new SABRE auroral radar, are presented. During a 3-hour period in the early morning of September 19, 1981, a train of pulsations were recorded. Analysis revealed that there were three main events, rather than one continuous disturbance. The first event appeared as a perturbation of only one or two cycles, extending throughout the latitude of the viewing area. It was also visible in the STARE region, but the perturbation drift velocity was in the north-south direction as opposed to the east-west perturbation drift of a more conventional toroidal mode field line resonance. The second disturbance was an isolated, one-cycle perturbation, also visible throughout both SABRE and STARE viewing areas and also having a dominant north-south velocity component. Finally, a very localized monochromatic event, lasting five cycles or more, with a period of about 5 min, was recorded. The characteristics of the third event were found to be consistent with those predicted by field line resonance theory.