Identification of acoustic-gravity wave modes from ionospheric range-time observations

The nuclear detonation at Novaya Semlya on October 30, 1961, produced a traveling disturbance in the ionosphere that was recorded by ionospheric sounding stations on the European continent. A compilation of the times of occurrence of maximums in perturbation at various stations permits a determination of the propagation speeds of various components of the disturbance. By comparing such data with theory, we find that the disturbances were the acoustic modes, the fundamental, and the second to fifth gravity-wave modes of fully ducted, acoustic-gravity waves.