# Estimating tropospheric and stratospheric winds using infrasound from explosions

## TL;DR

This study demonstrates that atmospheric cross-winds in the troposphere and stratosphere can be estimated directly from infrasound signals generated by surface explosions, using propagation time and backazimuth deviations.

## Contribution

It introduces a method to estimate atmospheric cross-winds from infrasound data, validated against reanalysis data, enhancing atmospheric wind measurement techniques.

## Key findings

- Infrasound from explosions can reveal cross-wind information.
- Estimated cross-winds agree well with ERA-Interim reanalysis.
- Partial reflections enable observations despite shadow zones.

## Abstract

The receiver-to-source backazimuth of atmospheric infrasound signals is biased when cross-winds are present along the propagation path. Infrasound from 598 surface explosions from over 30 years in northern Finland is measured with high spatial resolution on an array 178 km almost due North. The array is situated in the classical shadow-zone distance from the explosions. However, strong infrasound is almost always observed, which is most plausibly due to partial reflections from stratospheric altitudes. The most probable propagation paths are subject to both tropospheric and stratospheric cross-winds, and our wave-propagation modelling yields good correspondence between the observed backazimuth deviation and cross-winds from the ERA-Interim reanalysis product. We demonstrate that atmospheric cross-winds can be estimated directly from infrasound data using propagation time and backazimuth deviation observations. We find these cross-wind estimates to be in good agreement with the ERA-Interim reanalysis.