Characteristics of the August 1972 Solar Particle Events as Observed over the Earth's Polar Caps
LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA PALO ALTO RESEARCH LAB
Pagination or Media Count:
The fluxes and spectra of solar protons in the energy range 1-100 MeV have been measured over the earths polar caps at an altitude of 800 km aboard the satellite 1971-089A during the intense solar particle events of 3-12 August 1972. Differential proton fluxes in the energy intervals 1-4.5 MeV, 5-20 MeV and 20-100 MeV are presented as a function of time throughout the events. The fluxes of 0.76-2.1 MeV energetic electrons are also presented. Differential spectra of protons, alpha particles and electrons over the south central polar cap are shown for 1102 UT on 4 August and 0144 UT on 9 August 1972. Comparisons of the peak and integrated fluxes measured in this experiment with another measurement made during these events and with other large events in the previous solar cycle have been made. The 29-100 MeV proton fluxes measured over the polar caps in this experiment are in good agreement with the greater than 30- MeV proton measurements of Bostrom et al. 1972 made in interplanetary space and in the magnetosphere. The present data indicate that the 4 August 1972 event was the largest solar particle event observed near earth in the last two decades.
- Atmospheric Physics