Analysis of infrasound array data from tornadic storms in the southeastern United States

Area of Science:

• Atmospheric Science
• Geophysics
• Acoustics

Background:

• Infrasound monitoring offers potential for detecting severe weather events like tornadoes.
• Understanding infrasound propagation and noise is crucial for accurate signal detection.

Purpose of the Study:

• To analyze infrasound data from tornado events in the southeastern US.
• To determine the dominant infrasound frequencies associated with tornadoes.
• To assess the influence of atmospheric conditions on infrasound detection.

Main Methods:

• Analysis of infrasound data from sensor arrays during tornado touchdowns.
• Application of array signal processing techniques for source resolution.
• Atmospheric propagation modeling and wind noise analysis.

Main Results:

• Accurate bearings were obtained for tornadoes up to 100 km away.
• Dominant coherent infrasound frequencies ranged from 2 to 6 Hz.
• Detected signals correlated with convective storm cells, including non-tornadic ones.

Conclusions:

• Infrasound arrays can detect and localize tornadoes.
• The 2-6 Hz frequency band is significant for tornado infrasound.
• Atmospheric conditions and advanced processing are key for reliable detection.