Sound producing mechanism in temperature inversion layer and its sensitivity to geomagnetic activity

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorLaine, Unto K.en_US
dc.contributor.departmentDept Signal Process and Acousten
dc.date.accessioned2023-03-07T13:30:19Z
dc.date.available2023-03-07T13:30:19Z
dc.date.issued2022en_US
dc.description.abstractSounds associated with aurora borealis, so called Auroral Sounds (AS), are explained by electrical discharges occurring in Temperature Inversion Layer (TIL) approximately 75 meters above the ground. It is assumed that under favorable weather conditions the number of AS events depends on the activity of the geomagnetic (GM) storm. The historical testimonies of AS indicate that the GM storm should be strong enough to rise the bright and lively auroras to the zenith before these sounds can be observed. The goal of this study is to test the relevancy of this claim by studying the sensitivity of the AS producing mechanism under a moderate GM activity. A four-hour long period of the sound measurements done around the local magnetic midnight Jan 25–26, 2022 at Fiskars village, Finland, is analyzed. Sixty AS event candidates were manually selected and their temporal distribution and period histogram constructed for statistical comparisons with the GM data measured simultaneously by the Finnish Meteorological Institute (FMI) at Nurmijärvi Geophysical Observatory (NGO). The data was also used for regression models to study possible causal relationship between the GM activity and the AS events. A strong causality between the GM activity and the AS events was found. The sounds were predicted by the GM activity with 90% accuracy after a delay of 21 min. The results show that the AS events are much more common than previously thought.en
dc.description.versionPeer revieweden
dc.format.extent10
dc.format.extent365-374
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationLaine, U K 2022, Sound producing mechanism in temperature inversion layer and its sensitivity to geomagnetic activity . in EUROREGIA BNAM 2022 Conference Proceedings . BNAM, Nordic Acoustic Association (NAA), pp. 365-374, Joint Acoustics Conference, Aalborg, Denmark, 09/05/2022 . < https://bnam2022.org/wp-content/uploads/2022/05/ERBNAM2022_Proceedings.pdf >en
dc.identifier.isbn978-87-995400-5-1
dc.identifier.issn2245-4365
dc.identifier.otherPURE UUID: a1d43e9f-6771-47b5-af95-6979ce3ef068en_US
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/a1d43e9f-6771-47b5-af95-6979ce3ef068en_US
dc.identifier.otherPURE LINK: https://bnam2022.org/wp-content/uploads/2022/05/ERBNAM2022_Proceedings.pdfen_US
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/102066680/Laine_ERBNAM2022_Proceedings.pdfen_US
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/120007
dc.identifier.urnURN:NBN:fi:aalto-202303072335
dc.language.isoenen
dc.relation.ispartofJoint Acoustics Conferenceen
dc.relation.ispartofseriesEUROREGIA BNAM 2022 Conference Proceedingsen
dc.relation.ispartofseriesBNAMen
dc.rightsopenAccessen
dc.titleSound producing mechanism in temperature inversion layer and its sensitivity to geomagnetic activityen
dc.typeA4 Artikkeli konferenssijulkaisussafi
dc.type.versionpublishedVersion
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