The acoustic field in the atmosphere and ionosphere caused by a point explosion on the ground

In this paper, we present a set of equations and their solutions which describe the propagation of acoustic pulses through a model terrestrial atmosphere due to a chemical explosion on the ground, and the effects of these pulses on the ionosphere above the explosion. Our calculations appear to agree remarkably well with acoustic and radio sounding data measured for the 1981 Mill Race explosion at seven different altitudes from approximately 10-260 km. We show that (i) the acoustic wave speed depends on the viscosity and thermal conductivity of the atmosphere, (ii) the amplitude of the fluid velocity in the acoustic wave reaches a maximum at an altitude of about 120 km, (iii) the altitude of the maximum does not depend on the initial launch angle of the acoustic wavefront or the size of the explosion, and (iv) the path taken by different parts of the acoustic wavefront depends on the yield of explosion. (C) 2003 Elsevier Science Ltd. All rights reserved.