Lighthill's theory applied to tornadoes as an infrasonic source

Abstract

It has been shown that tornadoes radiate infrasound, which can be detected at great distances. The physical mechanism underlying the radiation is not well understood. In this work, we use Lighthill's acoustic analogy to predict the pressure signals emitted from numerically simulated tornadoes. Several simulations will be considered including simulations produced using an LES model and provided by researchers from the Penn State Department of Meteorology and Atmospheric Science. The acoustical source produced from the LES tornado simulations shows interesting patterns in a narrow low-frequency band. By comparing different numerical models of tornadoes, we hope to determine what in a tornado is causing the infrasound radiation.