Observations of Solar Flare Radiation and Modulation Effects at Balloon Altitudes, July 1959
Abstract
Observations of cosmic-ray time variations in the stratosphere were obtained over Berkeley, California (USA), and Lindau/Harz (Germany) during the period of outstanding solar activity in July 1959. Whereas over Berkeley (geomagnetic latitude 44°N) only modulation of cosmic radiation by solar-controlled processes was observed, additional radiation accelerated in the vicinity of the sun (approximately 46 per cent above normal) was observed over Lindau (geomagnetic latitude 52°N) on July 15. On the assumption that the excess radiation consisted almost entirely of protons, its energy spectrum had the form N(E)dE ∼E-4 dE and extended up to 400 Mev. According to conventional geomagnetic theory, individual protons of these energies are normally forbidden at geomagnetic latitude 52°N. Their presence over Lindau on July 15 indicates that they were admitted by some mechanism which temporarily lowers the cutoff rigidity at this latitude during a magnetic storm. There is also some indication of further examples of excess radiation over Lindau at atmospheric depths down to 30 mm Hg on July 13, 21, 23, and 31.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- September 1960
- DOI:
- 10.1029/JZ065i009p02685
- Bibcode:
- 1960JGR....65.2685E