Identification of Acoustic and Gravity-wave Modes associated with Travelling Ionospheric Disturbances caused by Nuclear Explosions

Abstract

NATURALLY occurring travelling ionospheric disturbances (TIDs) have been detected and measured for about 30 yr, and Martyn¹ suggested, about 17 yr ago, that they are propagating atmospheric gravity waves. Later a quantitative agreement was found between the observed speed distributions of TIDs and those that are expected theoretically for ducted acoustic-gravity waves. Furthermore, there is agreement between theory and the observed speeds of TIDs caused by a nuclear detonation at Novaya Zemlya^2–4. Further data became available in 1967 when Breitling et al.⁵ published a summary of measurements made on nuclear tests in the Pacific area. Their data also agree with theory and are accurate enough to permit resolution of the fine structure in the acoustic modes.