Recent developments on the prediction and interpretation of infrasonic signals from large explosions

Infrasonic signals generated by large explosions can be detected thousands of kilometers from the explosion. Propagation of such signals depends on temperature gradients and wind shear in the atmosphere from the ground up to the thermosphere. The atmosphere is highly dynamic and variable and while there are qualitative seasonal trends that can be identified, it can be said with a fair degree of certainty that the detailed atmosphere that one finds at any given time will never repeat itself again. Despite this, using simplified atmospheric models, one can make concrete statements about the evolution of infrasonic waveforms. Along favorable propagation paths waveform predictions can be validated by observation. In other cases, atmospheric volatility plays a central role. Recent developments from theory and experiment will be presented.