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dc.contributor.authorLeyser, Thomas B.
dc.contributor.authorSergienko, Tima
dc.contributor.authorBrändström, Urban
dc.contributor.authorGustavsson, Björn Johan
dc.contributor.authorRietveld, Michael T.
dc.date.accessioned2024-01-12T12:26:45Z
dc.date.available2024-01-12T12:26:45Z
dc.date.issued2023-12-13
dc.description.abstractThe EISCAT (European Incoherent Scatter Scientific Association) Heating facility was used to transmit powerful high-frequency (HF) electromagnetic waves into the Fregion ionosphere to enhance optical emissions at 557.7 and 630.0 nm from atomic oxygen. The emissions were imaged by several stations of ALIS (Auroral Large Imaging System) in northern Sweden, and the EISCAT UHF incoherent scatter radar was used to obtain plasma parameter values. The ratio of the 557.7 to 630.0 nm column emission rates changed from I<sub>5577</sub>/I<sub>6300</sub> ≈ 0.2 for the HF pump frequency f<sub>0</sub> = 6.200 MHz ≈ 4.6f<sub>e</sub> to I<sub>5577</sub>/I<sub>6300</sub> ≈ 0.5 when f<sub>0</sub> = 5.423 MHz . 4f<sub>e</sub>, where f<sub>e</sub> is the ionospheric electron gyro frequency. The observations are interpreted in terms of decreased electron heating efficiency and thereby weaker enhancement at 630.0 nm for f<sub>0</sub> = 5.423 MHz . 4 f<sub>e</sub>. The emissions at 557.7 nm are attributed to electron acceleration by upper hybrid waves of metre-scale wavelengths that can be excited with f<sub>0</sub> = 5.423 MHz . 4 f<sub>e</sub>.en_US
dc.identifier.citationLeyser, Sergienko, Brändström, Gustavsson, Rietveld. On mechanisms for high-frequency pump-enhanced optical emissions at 557.7 and 630.0gnm from atomic oxygen in the high-latitude F-region ionosphere. Annales Geophysicae. 2023;41(2):589-600en_US
dc.identifier.cristinIDFRIDAID 2223656
dc.identifier.doi10.5194/angeo-41-589-2023
dc.identifier.issn0992-7689
dc.identifier.issn1432-0576
dc.identifier.urihttps://hdl.handle.net/10037/32445
dc.language.isoengen_US
dc.publisherCopernicus Publicationsen_US
dc.relation.journalAnnales Geophysicae
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2023 The Author(s)en_US
dc.rights.urihttps://creativecommons.org/licenses/by/4.0en_US
dc.rightsAttribution 4.0 International (CC BY 4.0)en_US
dc.titleOn mechanisms for high-frequency pump-enhanced optical emissions at 557.7 and 630.0gnm from atomic oxygen in the high-latitude F-region ionosphereen_US
dc.type.versionpublishedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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Attribution 4.0 International (CC BY 4.0)
Except where otherwise noted, this item's license is described as Attribution 4.0 International (CC BY 4.0)