Contribution
Case studies of long-range infrasound propagation modelling
* Presenting author
Abstract:
Infrasound, i.e. acoustic waves with frequencies below 20 Hz, can propagate over very long distances through the atmosphere. As opposed to human-audible sound, infrasound experiences low attenuation, enabling the detection of remote sources at receivers so called micro-barometers hundreds to thousands kilometres away when an atmospheric waveguide establishes. Atmospheric waveguides depend on the vertical profiles of wind and temperature from the ground to the thermosphere (~120 km altitude), while the most efficient waveguides form near the stratopause (~50 km) or, for shorter ranges, in the troposphere (<15 km).Dedicated models are capable of incorporating the state of the atmosphere and simulating the propagation of infrasound at different frequencies. These include ray-tracing methods and the parabolic equation modelling, as well as semi-empirical parameterizations to reduce the computational effort. In this contribution, we will utilize and compare different models to investigate recent or major infrasound events detected by infrasound arrays of the International Monitoring System for the Comprehensive Nuclear-Test-Ban Treaty, such as fireballs, explosions and rocket launches for space missions.