Geomagnetic and Ionospheric Effects at Brisbane Following the Nuclear Explosion on July 9, 1962

Abstract

Ionospheric data and geomagnetic micropulsation records from Brisbane have revealed both short· term and delayed effects associated with the U.S. nuclear explosion on July 9, 1962 above Johnston I. The initial ionospheric effects, lasting about 30 s, appeared to be due to severe low·level (D-region) blanketing, probably arising from the dumping of neutron decay products. The micropulsations initiated by the explosion were detected for about 5 min; after an initial transient, they became suppressed during the time when the low-level blanketing ionization was present.