Infrasound waves can probe some of the most complex weather patterns hidden from normal observations. But finding a powerful enough source of infrasound waves can be a challenge unless there is a munitions factory nearby. Stephen Arrowsmith from Southern Methodist University will discuss a method for using infrasound pulses from detonated munitions to probe atmospheric phenomena.
Infrasound waves are acoustic waves at frequencies too low for humans to hear. But they can be invaluable for studying atmospheric phenomena. One example is gravity waves which are small-scale waves in the atmosphere driven by buoyancy. These waves are small and transient which makes them challenging to study with traditional methods. Infrasound waves have the speed and resolution to track those gravity waves.
These infrasound waves need to be strong enough to reach the atmosphere and bounce back. It requires a sizeable source. Fortunately for Arrowsmith, an Oklahoma munitions factory routinely sets off large explosions multiple times per day. He and his team set up detectors in the area around the factory to measure infrasound reflections from the troposphere and stratosphere.
They were able to use the data to study short-term atmospheric fluctuations and tie those fluctuations to gravity waves and other events. They then compared their data across multiple days to study longer-term trends and compare those to meteorological models.