Infrasound generation by tornadic supercell storms

TL;DR

This paper investigates how turbulence in moist, stratified atmospheres generates infrasound during tornadic supercell storms, highlighting the dominance of monopole sources related to moisture condensation.

Contribution

It introduces the role of monopole sources from moisture condensation as a significant infrasound generation mechanism in tornadic storms, expanding existing acoustic models.

Findings

Monopole sources dominate infrasound generation in strong storms.

Acoustic power estimates align with observed storm infrasound.

Results support moisture condensation as key infrasound source.

Abstract

Acoustic wave generation by turbulence in the stratified, moist atmosphere is studied. It is shown that in the saturated moist air turbulence in addition to the Lighthill's quadrupole and the dipole sources of sound related to stratification and temperature fluctuations, there exist monopole sources related to heat and mass production during the condensation of moisture. We determine acoustic power of these monopole sources. Performed analysis shows that the monopole radiation is dominant for typical parameters of strong convective storms. Obtained results are in good qualitative agreement with the main observed characteristics of infrasound radiation by strong convective storms such as total acoustic power and characteristic frequency.