High Altitude Nuclear Burst Research Articles

Nuclear burst effects on long-distance high-frequency circuits

In anticipation of the U.S. high-altitude nuclear burst series in the Pacific, recordings were made at Lexington, Massachusetts, of the field strength of Radio Australia on 11.71 Mc/s over a period of several months commencing on April 26, 1962, and ending on August 9, 1962. The recording series was rather complete in respect to three separate transmissions made on this frequency: transmission A, 0540–0915 GMT; transmission B, 1214–1310 GMT; and transmission C, 1513–1615 GMT. Fields were recorded in terms of microvolts input to a Stoddardt NM-2OB field intensity meter by means of a vertical wire about 60 feet in length strung up along the side of a building.

A note on the cause of sudden ionization anomalies in regions remote from high-altitude nuclear bursts

Sudden changes of VLF propagation characteristics, caused by the very high altitude Hardtack nuclear detonations in the summer of 1958, occurred on propagation paths thousands of kilometers from the burst point. The anomalies were caused by bomb-induced ionization in the ionospheric D layer, and their onset was much more sudden than those occasioned by natural phenomena such as solar flares. The model discussed provides an explanation of how ionization is suddenly produced in ionospheric regions shadowed from a high-altitude detonation or its conjugate point.