Some atmospheric effects on infrasound signal amplitudes

Abstract

In this chapter two types of infrasound propagation modes or paths through the atmosphere are introduced and their interaction with the atmosphere is discussed. A method is presented for an inversion process to obtain atmospheric properties from infrasonic signals. Two of the most important modes for atmospheric wave propagation, stratospheric region returns (S signals) and thermospheric region returns (T signals), are discussed and contrasted. The emphasis is on signals from chemical, or high explosive (HE) explosions and atmospheric nuclear explosions from past tests and earthquakes. The role of atmospheric winds in controlling S signals and the relative independence of T signals are explained. An empirical method for the prediction of wind effects, or normalization of those effects, on S signal amplitudes is presented. Three methods are presented for the inversion of amplitude observations to obtain atmospheric wind parameterization. © 2009 Springer Science+Business Media B.V.