Date of Award
Master of Science (MS)
Tornadoes--Forecasting, Infrasonic waves
Prior studies have hypothesized that there is a distinct correlation between the detection of acoustic infrasound signals, which consists of the range of acoustic frequencies below 20 Hz, and tornadoes leading to theories suggesting that infrasound may be a potential early warning indicator of tornadogenesis. To test this hypothesis, The University of Alabama in Huntsville - Severe Weather Institute Radar and Lightning Laboratories (UAH-SWIRLL) in collaboration with General Atomics - Electromagnetics Systems Group (GA-EMS) and the National Center for Physical Acoustics (NCPA), deployed a network of acoustic arrays capable of resolving signals in the infrasound regime across North Alabama in conjunction with the VORTEX-SE field campaign. Utilizing data collected during a severe weather event on 22 April 2017, an analysis of bearing estimates derived from the acoustic array data depicted substantial agreement between the direction of arrival of the infrasonic signals and the location of the storms relative to the array, implying that the storms detected were capable of producing observable infrasound at ranges in excess of 77 km. Further analyses that investigated whether or not these signals were directly related to tornadoes or the processes responsible for their formation were largely inconclusive. However, correlations between infrasound and metrics depicting other hypothesized infrasound generation mechanisms, such as lightning, were able to be established. As a result, there is substantial evidence indicating that thunderstorm generated infrasound cannot be utilized as a binary indicator of weak tornadoes or imminent tornadogenesis without first investigating alternative means of infrasound production within convective storms. Thus, in order to ultimately determine whether or not infrasound can be utilized as a reliable means of tornado detection, a more comprehensive dataset is needed for analysis.
Goudeau, Barrett, "A case study on the usage and efficacy of infrasound monitoring arrays as a means of tornado detection" (2018). Theses. 238.