Estimating tropospheric and stratospheric winds using infrasound from explosions

• Main Authors: Blixt, Erik Mårten, Näsholm, Sven Peter, Gibbons, Steven J., Evers, Läslo G., Charlton-Perez, Andrew J., Orsolini, Yvan J., Kværna, Tormod
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: arXiv 2019
• Subjects: Atmospheric and Oceanic Physics physics.ao-ph; Classical Physics physics.class-ph; Geophysics physics.geo-ph; FOS Physical sciences; Northern Finland
• Online Access: https://dx.doi.org/10.48550/arxiv.1907.05601; https://arxiv.org/abs/1907.05601

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. : This article has been accepted by The Journal of the Acoustical Society of America. After it is published, it will be found at http://asa.scitation.org/journal/jas The current e-print was typeset by the authors and can differ in, e.g., pagination, reference numbering, and typographic detail