Infrasound generation by turbulent convection

TL;DR

This paper investigates how turbulent convection in stratified atmospheres generates low-frequency infrasound, highlighting the significant roles of temperature inhomogeneities and stratification in acoustic wave production.

Contribution

It introduces a comprehensive model accounting for stratification and temperature fluctuations, revealing their substantial impact on infrasound generation in convective storms.

Findings

Dipole radiation from temperature inhomogeneities is comparable to Lighthill's quadrupole source.

Stratification-related sources can significantly contribute to infrasound.

Other potential sources are shown to be inefficient.

Abstract

Low frequency acoustic wave generation is studied taking into account the effect of stratification, inhomogeneity of background velocity profile and temperature fluctuations. It is shown that for the typical parameters of convective storms the dipole radiation related to temperature inhomogeneities is at least of the same order as radiation of Lighthill's quadrupole source. It is also shown that the source related to stratification could have valuable contribution whereas some other sources are shown to be inefficient.