The Cosmic Ray Ground-level Enhancement of 24 October 1989

• Published in: Publications of the Astronomical Society of Australia
• Main Authors: Cramp, J. L., Humble, J. E., Duldig, M. L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1994
• Subjects: South Pole; Antarc*; Antarctica; South pole
• Online Access: http://dx.doi.org/10.1017/s1323358000019627; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1323358000019627

Abstract The cosmic ray ground-level enhancement (GLE) of 24 October 1989 was the last of a series of GLEs associated with the same solar active region. Intensity enhancements were observed by at least 31 neutron monitors in the worldwide network, with the largest increase (~200%) observed at South Pole, Antarctica around 20:30 UT. Using a least-squares model fit to all available neutron monitor data, spectra, apparent source directions and particle pitch angle distributions have been derived. The effect of disturbed geomagnetic conditions has also been taken into account.