Infrasound propagation through the atmosphere with mesoscale wind velocity and temperature fluctuations

Abstract

Some results on modeling and observation of infrasound propagation in the atmosphere in a presence of mesoscale and anisotropic wind velocity and temperature fluctuations are presented. The theoretical model of infrasound scattering from anisotropic wind velocity and temperature inhomogeneities of the atmosphere is developed. With this model, the appearance of the stratospheric, mesospheric, and thermospheric arrivals of the infrasound signals in the acoustic shadow zones is explained. The analytic relation between the wave field of the scattered infrasound signal and the vertical profile of the effective sound speed fluctuations is obtained. Using this relation, the vertical profiles of the fluctuations within the upper stratosphere (25–55 km) and the lower thermosphere (105–140 km) were retrieved from the waveforms and travel times of the signals recorded in the acoustic shadow zones. The theoretical frequency spectrum of the infrasound wavefield reflected from the fine-scale layered structure of the atmosphere is obtained and compared with the spectra of the observed stratospheric arrivals.

KEYWORDS:

• Mesoscale
• anisotropic
• fluctuations
• infrasound
• scattering
• shadow zone
• arrivals
• internal gravity waves

Acknowledgements

This work was supported by the Russian Science Foundation (RSF) under Grant 21-17-00021 (Sections 2–4) and Russian Foundation for Basic Research (RFBR) under Grant 19-05-0008 (Section 5).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Russian Science Foundation (RSF): [Grant Number 21-17-00021].