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<!DOCTYPE html> <html lang="en" class="no-js"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="applicable-device" content="pc,mobile"> <meta name="viewport" content="width=device-width, initial-scale=1"> <meta name="robots" content="max-image-preview:large"> <meta name="access" content="Yes"> <meta name="360-site-verification" content="1268d79b5e96aecf3ff2a7dac04ad990" /> <title>Atmospheric Gravity Waves and Medium Scale Traveling Ionospheric Disturbances at Auroral Latitudes | Surveys in Geophysics </title> <meta name="twitter:site" content="@SpringerLink"/> <meta name="twitter:card" content="summary_large_image"/> <meta name="twitter:image:alt" content="Content cover image"/> <meta name="twitter:title" content="Atmospheric Gravity Waves and Medium Scale Traveling Ionospheric Disturbances at Auroral Latitudes"/> <meta name="twitter:description" content="Surveys in Geophysics - To investigate physical links between the Earth atmosphere and ionosphere, we present data of the medium-scale atmospheric gravity waves (AGWs, periods..."/> <meta name="twitter:image" content="https://static-content.springer.com/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig1_HTML.png"/> <meta name="journal_id" content="10712"/> <meta name="dc.title" content="Atmospheric Gravity Waves and Medium Scale Traveling Ionospheric Disturbances at Auroral Latitudes"/> <meta name="dc.source" content="Surveys in Geophysics 2025"/> <meta name="dc.format" content="text/html"/> <meta name="dc.publisher" content="Springer"/> <meta name="dc.date" content="2025-03-06"/> <meta name="dc.type" content="ReviewPaper"/> <meta name="dc.language" content="En"/> <meta name="dc.copyright" content="2025 The Author(s)"/> <meta name="dc.rights" content="2025 The Author(s)"/> <meta name="dc.rightsAgent" content="journalpermissions@springernature.com"/> <meta name="dc.description" content="To investigate physical links between the Earth atmosphere and ionosphere, we present data of the medium-scale atmospheric gravity waves (AGWs, periods 25–100&nbsp;min) observed at auroral latitudes. The AGWs at 80–100&nbsp;km altitude were inferred from the wind data of the Nordic meteor radar Cluster with spatial/height/time resolution 90&nbsp;km/5&nbsp;km/10&nbsp;min respectively. At the same time, medium-scale traveling ionospheric disturbances (MSTIDs) were detected as variations of the electron density (critical frequency foF2) at the height of F2 maximum (hmF2, 250–350&nbsp;km) in the data of the ionosonde at Sodankylä Geophysical Observatory (67°N, 27°E, Finland) operating with 1-min time resolution. We found that, except a “fall anomaly” in mid-September–mid-December, the season-local time distributions of AGW at 90&nbsp;km and MSTID at hmF2 are similar. Namely, larger amplitudes are observed in the dark-sky conditions, such that the separation between smaller and larger amplitudes occurs at solar terminator. However, during the fall anomaly, amplitudes of MSTID at hmF2 are the same as in spring- and wintertime, whereas AGWs at 90&nbsp;km are practically suppressed. This anomaly starts with the fall transition in the atmospheric circulation and is associated with a sharp change of the phase of semi-diurnal tides. The results are consistent with the idea that the AGWs observed near the mesopause may be generated due to turbulence in the lower atmosphere (below) or due to electrodynamical forces and auroral activity in the ionospheric E-layer. The latter plays a major role in the auroral region and may be more important in dark-sky conditions."/> <meta name="prism.issn" content="1573-0956"/> <meta name="prism.publicationName" content="Surveys in Geophysics"/> <meta name="prism.publicationDate" content="2025-03-06"/> <meta name="prism.section" content="ReviewPaper"/> <meta name="prism.startingPage" content="1"/> <meta name="prism.endingPage" content="17"/> <meta name="prism.copyright" content="2025 The Author(s)"/> <meta name="prism.rightsAgent" content="journalpermissions@springernature.com"/> <meta name="prism.url" content="https://link.springer.com/article/10.1007/s10712-025-09880-0"/> <meta name="prism.doi" content="doi:10.1007/s10712-025-09880-0"/> <meta name="citation_pdf_url" content="https://link.springer.com/content/pdf/10.1007/s10712-025-09880-0.pdf"/> <meta name="citation_fulltext_html_url" content="https://link.springer.com/article/10.1007/s10712-025-09880-0"/> <meta name="citation_journal_title" content="Surveys in Geophysics"/> <meta name="citation_journal_abbrev" content="Surv Geophys"/> <meta name="citation_publisher" content="Springer Netherlands"/> <meta name="citation_issn" content="1573-0956"/> <meta name="citation_title" content="Atmospheric Gravity Waves and Medium Scale Traveling Ionospheric Disturbances at Auroral Latitudes"/> <meta name="citation_online_date" content="2025/03/06"/> <meta name="citation_firstpage" content="1"/> <meta name="citation_lastpage" content="17"/> <meta name="citation_article_type" content="Article"/> <meta name="citation_fulltext_world_readable" content=""/> <meta name="citation_language" content="en"/> <meta name="dc.identifier" content="doi:10.1007/s10712-025-09880-0"/> <meta name="DOI" content="10.1007/s10712-025-09880-0"/> <meta name="size" content="141363"/> <meta name="citation_doi" content="10.1007/s10712-025-09880-0"/> <meta name="citation_springer_api_url" content="http://api.springer.com/xmldata/jats?q=doi:10.1007/s10712-025-09880-0&api_key="/> <meta name="description" content="To investigate physical links between the Earth atmosphere and ionosphere, we present data of the medium-scale atmospheric gravity waves (AGWs, periods 25&"/> <meta name="dc.creator" content="Kozlovsky, Alexander"/> <meta name="dc.creator" content="Stober, Gunter"/> <meta name="dc.creator" content="Sherstyukov, Ruslan"/> <meta name="dc.creator" content="Lester, Mark"/> <meta name="dc.creator" content="Belova, Evgenia"/> <meta name="dc.creator" content="Kero, Johan"/> <meta name="dc.creator" content="Tsutsumi, Masaki"/> <meta name="dc.creator" content="Gulbrandsen, Njål"/> <meta name="dc.creator" content="Nozawa, Satonori"/> <meta name="dc.subject" content="Geophysics/Geodesy"/> <meta name="dc.subject" content="Earth Sciences, general"/> <meta name="dc.subject" content="Astronomy, Observations and Techniques"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res; citation_title=The Joule heat production rate and the particle energy injection rate as a function of the geomagnetic indices AE and AL; citation_author=B-H Ahn, S-I Akasofu, Y Kamide; citation_volume=88; citation_issue=A8; citation_publication_date=1983; citation_pages=6275-6287; citation_doi=10.1029/JA088iA08p06275; citation_id=CR1"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res; citation_title=Statistical distribution of height-integrated energy exchange rates in the ionosphere; citation_author=AT Aikio, L Cai, T Nygrén; citation_volume=117; citation_publication_date=2012; citation_pages=A10325; citation_doi=10.1029/2012JA018078; citation_id=CR2"/> <meta name="citation_reference" content="citation_journal_title=Rev Geophys; citation_title=The international reference ionosphere model: a review and description of an ionospheric benchmark; citation_author=D Bilitza, M Pezzopane, V Truhlik, D Altadill, BW Reinisch, A Pignalberi; citation_volume=60; citation_publication_date=2022; citation_pages=e2022RG000792; citation_doi=10.1029/2022RG000792; citation_id=CR3"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res; citation_title=On the seasonal dependence of medium-scale atmospheric gravity waves in the upper atmosphere at high latitudes; citation_author=W Bristow, R Greenwald, J Villain; citation_volume=101; citation_issue=A7; citation_publication_date=1996; citation_pages=15685-15699; citation_doi=10.1029/96ja01010; citation_id=CR4"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Space; citation_title=Height-dependent energy exchange rates in the high-latitude E region ionosphere; citation_author=L Cai, AT Aikio, T Nygrén; citation_volume=118; citation_publication_date=2013; citation_pages=7369-7383; citation_doi=10.1002/2013JA019195; citation_id=CR5"/> <meta name="citation_reference" content="citation_journal_title=Ann Geophys; citation_title=Semidiurnal solar tide differences between fall and spring transition times in the Northern Hemisphere; citation_author=JF Conte, JL Chau, FI Laskar, G Stober, H Schmidt, P Brown; citation_volume=36; citation_issue=4; citation_publication_date=2018; citation_pages=999-1008; citation_doi=10.5194/angeo-36-999-2018; citation_id=CR6"/> <meta name="citation_reference" content="citation_journal_title=Geosci Instrum Method Data Syst; citation_title=Comparison between manual scaling and Autoscala automatic scaling applied to Sodankylä geophysical observatory ionograms; citation_author=C-F Enell, A Kozlovsky, T Turunen, T Ulich, S Välitalo, C Scotto, M Pezzopane; citation_volume=5; citation_issue=1; citation_publication_date=2016; citation_pages=53-64; citation_doi=10.5194/gi-5-53-2016; citation_id=CR7"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Space; citation_title=Climatology of medium-scale traveling ionospheric disturbances observed by the midlatitude Blackstone SuperDARN radar; citation_author=N Frissell, J Baker, J Ruohoniemi, A Gerrard, E Miller, J Marini; citation_volume=119; citation_issue=9; citation_publication_date=2014; citation_pages=7679-7697; citation_doi=10.1002/2014ja019870; citation_id=CR8"/> <meta name="citation_reference" content="citation_journal_title=Ann Geophys; citation_title=Inferring neutral winds in the ionospheric transition region from atmospheric-gravity-wave traveling-ionospheric-disturbance (AGW-TID) observations with the EISCAT VHF radar and the Nordic Meteor Radar Cluster; citation_author=F Günzkofer, D Pokhotelov, G Stober, I Mann, SL Vadas, E Becker, A Tjulin, A Kozlovsky, M Tsutsumi, N Gulbrandsen, S Nozawa, M Lester, E Belova, J Kero, NJ Mitchell, C Borries; citation_volume=41; citation_publication_date=2023; citation_pages=409-428; citation_doi=10.5194/angeo-41-409-2023; citation_id=CR9"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Space; citation_title=Statistical study of seasonal and solar activity dependence of nighttime MSTIDs occurrence using the SuperDARN Hokkaido pair of radars; citation_author=W Hazeyama, N Nishitani, T Hori, T Nakamura, S Perwitasari; citation_volume=127; citation_publication_date=2022; citation_pages=e2021JA029965; citation_doi=10.1029/2021JA029965; citation_id=CR10"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res; citation_title=On the propagation of atmospheric gravity waves through regions of wind shear; citation_author=CO Hines, CA Reddy; citation_volume=72; citation_issue=3; citation_publication_date=1967; citation_pages=1015-1034; citation_doi=10.1029/JZ072i003p01015; citation_id=CR11"/> <meta name="citation_reference" content="citation_journal_title=J Atmos Sol Terr Phys; citation_title=Real-time determination of meteor-related parameters utilizing modern digital technology; citation_author=WK Hocking, B Fuller, B Vandepeer; citation_volume=63; citation_issue=2; citation_publication_date=2001; citation_pages=155-169; citation_doi=10.1016/S1364-6826(00)00138-3; citation_id=CR12"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res; citation_title=The ionospheric response to internal gravity waves: 1. The f2 region response; citation_author=WH Hooke; citation_volume=75; citation_issue=28; citation_publication_date=1970; citation_pages=5535-5544; citation_doi=10.1029/JA075i028p05535; citation_id=CR13"/> <meta name="citation_reference" content="citation_journal_title=Nature; citation_title=The sources of gravity waves; citation_author=R Hunsucker; citation_volume=328; citation_publication_date=1987; citation_pages=204-205; citation_doi=10.1038/328204a0; citation_id=CR14"/> <meta name="citation_reference" content="citation_journal_title=Rev Geophys; citation_title=Atmospheric gravity waves generated in the high- latitude ionosphere: a review; citation_author=RD Hunsucker; citation_volume=20; citation_issue=2; citation_publication_date=1982; citation_pages=293-315; citation_doi=10.1029/RG020i002p00293; citation_id=CR15"/> <meta name="citation_reference" content="citation_journal_title=J Acoust Soc Am; citation_title=Infrasound from convective storms. III. Propagation to the ionosphere; citation_author=RM Jones, TM Georges; citation_volume=59; citation_publication_date=1976; citation_pages=765-779; citation_doi=10.1121/1.380942; citation_id=CR16"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res; citation_title=Characteristics of high-latitude TIDs from different causative mechanisms deduced by theoretical modeling; citation_author=G Kirchengast; citation_volume=102; citation_issue=A3; citation_publication_date=1997; citation_pages=4597-4612; citation_doi=10.1029/96ja03294; citation_id=CR17"/> <meta name="citation_reference" content="citation_journal_title=Earth Planet Sp; citation_title=Statistical study of medium-scale traveling ionospheric disturbances observed with the GPS networks in southern California; citation_author=N Kotake, Y Otsuka, T Ogawa, T Tsugawa, A Saito; citation_volume=59; citation_issue=2; citation_publication_date=2007; citation_pages=95-102; citation_doi=10.1186/bf03352681; citation_id=CR18"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Space; citation_title=Rapid-run ionosonde observations of traveling ionospheric disturbances in the auroral ionosphere; citation_author=A Kozlovsky, T Turunen, T Ulich; citation_volume=118; citation_issue=8; citation_publication_date=2013; citation_pages=5265-5276; citation_doi=10.1002/jgra.50474; citation_id=CR19"/> <meta name="citation_reference" content="citation_journal_title=Geophys Res Lett; citation_title=Spring-fall asymmetry in VLF amplitudes recorded in the North Atlantic region: The fall-effect; citation_author=EL Macotela, M Clilverd, T Renkwitz, J Chau, J Manninen, D Banyś; citation_volume=48; citation_publication_date=2021; citation_pages=e2021GL094581; citation_doi=10.1029/2021GL094581; citation_id=CR20"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Atmos; citation_title=Vertical structure of the Arctic spring transition in the middle atmosphere; citation_author=V Matthias, G Stober, A Kozlovsky, M Lester, E Belova, J Kero; citation_volume=126; citation_publication_date=2021; citation_pages=e2020JD034353; citation_doi=10.1029/2020JD034353; citation_id=CR21"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Space; citation_title=Statistics of traveling ionospheric disturbances at high latitudes using a rapid-run ionosonde; citation_author=ST Moges, RO Sherstyukov, A Kozlovsky, T Ulich, M Lester; citation_volume=129; citation_publication_date=2024; citation_pages=e0230JA31694; citation_doi=10.1029/2023JA031694; citation_id=CR22"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Space; citation_title=Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes; citation_author=ST Moges, A Kozlovsky, RO Sherstyukov, T Ulich; citation_volume=129; citation_publication_date=2024; citation_pages=e2024JA033013; citation_doi=10.1029/2024JA033013; citation_id=CR23"/> <meta name="citation_reference" content="citation_journal_title=Nature; citation_title=Suppression of discrete aurorae by sunlight; citation_author=P Newell, C-I Meng, K Lyons; citation_volume=381; citation_publication_date=1996; citation_pages=766-767; citation_doi=10.1038/381766A0; citation_id=CR24"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res Space; citation_title=Radar observations of simultaneous traveling ionospheric disturbances and atmospheric gravity waves; citation_author=T Nygren, A Aikio, M Voiculescu, L Cai; citation_volume=120; citation_issue=5; citation_publication_date=2015; citation_pages=3949-3960; citation_doi=10.1002/2014JA020794; citation_id=CR25"/> <meta name="citation_reference" content="citation_journal_title=Pure Appl Geophys; citation_title=Climatology of medium-scale traveling ionospheric disturbances (MSTIDs) observed with GPS networks in the North African region; citation_author=TS Oluwadare, N Jakowski, CE Valladares, AO-O Akala, OE Abe, MM Alizadeh, H Schuh; citation_volume=179; citation_publication_date=2022; citation_pages=2501-2522; citation_doi=10.1007/s00024-022-03028-6; citation_id=CR26"/> <meta name="citation_reference" content="Otsuka Y (2021) Medium-scale traveling ionospheric disturbances. In: Huang C, Lu G, Zhang Y, Paxton LJ (ed) Ionosphere dynamics and applications. https://doi.org/10.1002/9781119815617.ch18 "/> <meta name="citation_reference" content="citation_journal_title=Earth Planets Space; citation_title=Solar activity dependence of medium-scale traveling ionospheric disturbances using GPS receivers in Japan; citation_author=Y Otsuka, A Shinbori, T Tsugawa, M Nishioka; citation_volume=73; citation_publication_date=2021; citation_pages=22; citation_doi=10.1186/s40623-020-01353-5; citation_id=CR28"/> <meta name="citation_reference" content="citation_journal_title=J Geophys Res; citation_title=Spread F and ionospheric currents; citation_author=F Perkins; citation_volume=78; citation_publication_date=1973; citation_pages=218-226; citation_doi=10.1029/JA078i001p00218; citation_id=CR29"/> <meta name="citation_reference" content="citation_journal_title=J Atmos Sol Terr Phys; citation_title=MF radar observations of seasonal variability of semidiurnal motions in the mesosphere at high northern and southern latitudes; citation_author=D Riggin, C Meyer, D Fritts, M Jarvis, Y Murayama, W Singer, R Vincent, D Murphy; citation_volume=65; citation_publication_date=2003; citation_pages=483-493; citation_doi=10.1016/S1364-6826(02)00340-1; citation_id=CR30"/> <meta name="citation_reference" content="citation_journal_title=Atmos Meas Tech; citation_title=Retrieval of intrinsic mesospheric gravity wave parameters using lidar and airglow temperature and meteor radar wind data; citation_author=R Reichert, B Kaifler, N Kaifler, M Rapp, P-D Pautet, MJ Taylor, A Kozlovsky, M Lester, R Kivi; citation_volume=12; citation_publication_date=2019; citation_pages=5997-6015; citation_doi=10.5194/amt-12-5997-2019; citation_id=CR31"/> <meta name="citation_reference" content="citation_journal_title=Adv Space Res; citation_title=Collocated ionosonde and dense GPS/GLONASS network measurements of mid-latitude MSTIDs; citation_author=R Sherstyukov, A Akchurin, O Sherstyukov; citation_volume=61; citation_issue=7; citation_publication_date=2018; citation_pages=1717-1725; citation_doi=10.1016/j.asr.2017.11.026; citation_id=CR32"/> <meta name="citation_reference" content="Sherstyukov R, Kozlovsky A, Ulich T, Moges S (2023) Deep learning for ionogram parameters scaling at polar region ionosphere. In: 2023 XXXVTH general assembly and scientific symposium of the international union of radio science (URSI GASS), pp 1–4. https://doi.org/10.23919/URSIGASS57860.2023.10265632 "/> <meta name="citation_reference" content="citation_journal_title=Earth Space Sci; citation_title=A deep learning approach for automatic ionogram parameters recognition with convolutional neural networks; citation_author=R Sherstyukov, S Moges, A Kozlovsky, T Ulich; citation_volume=11; citation_publication_date=2024; citation_pages=e2023EA003446; citation_doi=10.1029/2023EA003446; citation_id=CR34"/> <meta name="citation_reference" content="citation_journal_title=Atmos Meas Tech; citation_title=Atmospheric tomography using the Nordic meteor radar cluster and Chilean observation network de meteor radars: network details and 3DVAR retrieval; citation_author=G Stober, A Kozlovsky, A Liu, Z Qiao, M Tsutsumi, C Hall, S Nozawa, M Lester, E Belova, J Kero, PJ Espy, RE Hibbons, N Mitchell; citation_volume=14; citation_publication_date=2021; citation_pages=6509-6532; citation_doi=10.5194/amt-14-6509-2021; citation_id=CR35"/> <meta name="citation_reference" content="citation_journal_title=Ann Geophys; citation_title=Identifying gravity waves launched by the Hunga Tonga-Hunga Ha‘apai volcanic eruption in mesosphere/lower thermosphere winds derived from CONDOR and the Nordic Meteor Radar Cluster; citation_author=G Stober, A Liu, A Kozlovsky, Z Qiao, W Krochin, G Shi, J Kero; citation_volume=41; citation_publication_date=2023; citation_pages=197-208; citation_doi=10.5194/angeo-41-197-2023; citation_id=CR36"/> <meta name="citation_reference" content="citation_journal_title=Ann Geophys; citation_title=A study of traveling ionospheric disturbances and atmospheric gravity waves using EISCAT Svalbard Radar IPY-data; citation_author=A Vlasov, K Kauristie, M Kamp, J-P Luntama, A Pogoreltsev; citation_volume=29; citation_issue=11; citation_publication_date=2011; citation_pages=2101-2116; citation_doi=10.5194/angeo-29-2101-2011; citation_id=CR37"/> <meta name="citation_author" content="Kozlovsky, Alexander"/> <meta name="citation_author_email" content="alexander.kozlovsky@oulu.fi"/> <meta name="citation_author_institution" content="Sodankylä Geophysical Observatory of the University of Oulu, Sodankylä, Finland"/> <meta name="citation_author" content="Stober, Gunter"/> <meta name="citation_author_institution" content="Institute of Applied Physics and Oeschger Center for Climate Change Research, Microwave Physics, University of Bern, Bern, Switzerland"/> <meta name="citation_author" content="Sherstyukov, Ruslan"/> <meta name="citation_author_institution" content="Sodankylä Geophysical Observatory of the University of Oulu, Sodankylä, Finland"/> <meta name="citation_author" content="Lester, Mark"/> <meta name="citation_author_institution" content="Department of Physics and Astronomy, University of Leicester, Leicester, UK"/> <meta name="citation_author" content="Belova, Evgenia"/> <meta name="citation_author_institution" content="Swedish Institute of Space Physics (IRF), Kiruna, Sweden"/> <meta name="citation_author" content="Kero, Johan"/> <meta name="citation_author_institution" content="Swedish Institute of Space Physics (IRF), Kiruna, Sweden"/> <meta name="citation_author" content="Tsutsumi, Masaki"/> <meta name="citation_author_institution" content="National Institute of Polar Research, Tachikawa, Japan"/> <meta name="citation_author_institution" content="The Graduate University for Advanced Studies (SOKENDAI), Tokyo, Japan"/> <meta name="citation_author" content="Gulbrandsen, Njål"/> <meta name="citation_author_institution" content="Tromsø Geophysical Observatory, UiT – The Arctic University of Norway, Tromsø, Norway"/> <meta name="citation_author" content="Nozawa, Satonori"/> <meta name="citation_author_institution" content="Division for Ionospheric and Magnetospheric Research Institute for Space-Earth Environment Research, Nagoya University, Nagoya, Japan"/> <meta name="format-detection" content="telephone=no"/> <meta property="og:url" content="https://link.springer.com/article/10.1007/s10712-025-09880-0"/> <meta property="og:type" content="article"/> <meta property="og:site_name" content="SpringerLink"/> <meta property="og:title" content="Atmospheric Gravity Waves and Medium Scale Traveling Ionospheric Disturbances at Auroral Latitudes - Surveys in Geophysics"/> <meta property="og:description" content="To investigate physical links between the Earth atmosphere and ionosphere, we present data of the medium-scale atmospheric gravity waves (AGWs, periods 25–100 min) observed at auroral latitudes. The AGWs at 80–100 km altitude were inferred from the wind data of the Nordic meteor radar Cluster with spatial/height/time resolution 90 km/5 km/10 min respectively. At the same time, medium-scale traveling ionospheric disturbances (MSTIDs) were detected as variations of the electron density (critical frequency foF2) at the height of F2 maximum (hmF2, 250–350 km) in the data of the ionosonde at Sodankylä Geophysical Observatory (67°N, 27°E, Finland) operating with 1-min time resolution. We found that, except a “fall anomaly” in mid-September–mid-December, the season-local time distributions of AGW at 90 km and MSTID at hmF2 are similar. Namely, larger amplitudes are observed in the dark-sky conditions, such that the separation between smaller and larger amplitudes occurs at solar terminator. However, during the fall anomaly, amplitudes of MSTID at hmF2 are the same as in spring- and wintertime, whereas AGWs at 90 km are practically suppressed. This anomaly starts with the fall transition in the atmospheric circulation and is associated with a sharp change of the phase of semi-diurnal tides. The results are consistent with the idea that the AGWs observed near the mesopause may be generated due to turbulence in the lower atmosphere (below) or due to electrodynamical forces and auroral activity in the ionospheric E-layer. The latter plays a major role in the auroral region and may be more important in dark-sky conditions."/> <meta property="og:image" content="https://static-content.springer.com/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig1_HTML.png"/> <meta name="format-detection" content="telephone=no"> <link rel="apple-touch-icon" sizes="180x180" href=/oscar-static/img/favicons/darwin/apple-touch-icon-92e819bf8a.png> <link rel="icon" type="image/png" sizes="192x192" href=/oscar-static/img/favicons/darwin/android-chrome-192x192-6f081ca7e5.png> <link rel="icon" type="image/png" sizes="32x32" href=/oscar-static/img/favicons/darwin/favicon-32x32-1435da3e82.png> <link rel="icon" type="image/png" sizes="16x16" href=/oscar-static/img/favicons/darwin/favicon-16x16-ed57f42bd2.png> <link rel="shortcut icon" data-test="shortcut-icon" href=/oscar-static/img/favicons/darwin/favicon-c6d59aafac.ico> <meta name="theme-color" content="#e6e6e6">   <link rel="stylesheet" media="print" 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The AGWs at 80–100 km altitude were inferred from the wind data of the Nordic meteor radar Cluster with spatial/height/time resolution 90 km/5 km/10 min respectively. At the same time, medium-scale traveling ionospheric disturbances (MSTIDs) were detected as variations of the electron density (critical frequency foF2) at the height of F2 maximum (hmF2, 250–350 km) in the data of the ionosonde at Sodankylä Geophysical Observatory (67°N, 27°E, Finland) operating with 1-min time resolution. We found that, except a “fall anomaly” in mid-September–mid-December, the season-local time distributions of AGW at 90 km and MSTID at hmF2 are similar. Namely, larger amplitudes are observed in the dark-sky conditions, such that the separation between smaller and larger amplitudes occurs at solar terminator. However, during the fall anomaly, amplitudes of MSTID at hmF2 are the same as in spring- and wintertime, whereas AGWs at 90 km are practically suppressed. This anomaly starts with the fall transition in the atmospheric circulation and is associated with a sharp change of the phase of semi-diurnal tides. The results are consistent with the idea that the AGWs observed near the mesopause may be generated due to turbulence in the lower atmosphere (below) or due to electrodynamical forces and auroral activity in the ionospheric E-layer. The latter plays a major role in the auroral region and may be more important in dark-sky conditions.","datePublished":"2025-03-06T00:00:00Z","dateModified":"2025-03-06T00:00:00Z","pageStart":"1","pageEnd":"17","license":"http://creativecommons.org/licenses/by/4.0/","sameAs":"https://doi.org/10.1007/s10712-025-09880-0","keywords":["Atmospheric gravity waves","Traveling ionospheric disturbances","Meteor radar","Auroral ionosphere","Geophysics/Geodesy","Earth Sciences","general","Astronomy","Observations and 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Research","address":{"name":"National Institute of Polar Research, Tachikawa, Japan","@type":"PostalAddress"},"@type":"Organization"},{"name":"The Graduate University for Advanced Studies (SOKENDAI)","address":{"name":"The Graduate University for Advanced Studies (SOKENDAI), Tokyo, Japan","@type":"PostalAddress"},"@type":"Organization"}],"@type":"Person"},{"name":"Njål Gulbrandsen","affiliation":[{"name":"UiT – The Arctic University of Norway","address":{"name":"Tromsø Geophysical Observatory, UiT – The Arctic University of Norway, Tromsø, Norway","@type":"PostalAddress"},"@type":"Organization"}],"@type":"Person"},{"name":"Satonori Nozawa","affiliation":[{"name":"Nagoya University","address":{"name":"Division for Ionospheric and Magnetospheric Research Institute for Space-Earth Environment Research, Nagoya University, Nagoya, 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xlink:href="#icon-eds-i-arrow-right-medium"></use> </svg></a></p> </li> </ul> </div> <div class="u-mt-32"> </div> </header> </div> <div data-article-body="true" data-track-component="article body" class="c-article-body"> <section aria-labelledby="Abs1" data-title="Abstract" lang="en"><div class="c-article-section" id="Abs1-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Abs1">Abstract</h2><div class="c-article-section__content" id="Abs1-content"><p>To investigate physical links between the Earth atmosphere and ionosphere, we present data of the medium-scale atmospheric gravity waves (AGWs, periods 25–100 min) observed at auroral latitudes. The AGWs at 80–100 km altitude were inferred from the wind data of the Nordic meteor radar Cluster with spatial/height/time resolution 90 km/5 km/10 min respectively. At the same time, medium-scale traveling ionospheric disturbances (MSTIDs) were detected as variations of the electron density (critical frequency foF2) at the height of F2 maximum (hmF2, 250–350 km) in the data of the ionosonde at Sodankylä Geophysical Observatory (67°N, 27°E, Finland) operating with 1-min time resolution. We found that, except a “fall anomaly” in mid-September–mid-December, the season-local time distributions of AGW at 90 km and MSTID at hmF2 are similar. Namely, larger amplitudes are observed in the dark-sky conditions, such that the separation between smaller and larger amplitudes occurs at solar terminator. However, during the fall anomaly, amplitudes of MSTID at hmF2 are the same as in spring- and wintertime, whereas AGWs at 90 km are practically suppressed. This anomaly starts with the fall transition in the atmospheric circulation and is associated with a sharp change of the phase of semi-diurnal tides. The results are consistent with the idea that the AGWs observed near the mesopause may be generated due to turbulence in the lower atmosphere (below) or due to electrodynamical forces and auroral activity in the ionospheric E-layer. The latter plays a major role in the auroral region and may be more important in dark-sky conditions.</p></div></div></section> <div data-test="cobranding-download"> </div> <section aria-labelledby="inline-recommendations" data-title="Inline Recommendations" class="c-article-recommendations" data-track-component="inline-recommendations"> <h3 class="c-article-recommendations-title" id="inline-recommendations">Similar content being viewed by others</h3> <div class="c-article-recommendations-list"> <div class="c-article-recommendations-list__item"> <article class="c-article-recommendations-card" itemscope itemtype="http://schema.org/ScholarlyArticle"> <div class="c-article-recommendations-card__img"><img src="https://media.springernature.com/w215h120/springer-static/image/art%3A10.1134%2FS1990793120020207/MediaObjects/11826_2020_8183_Fig1_HTML.gif" loading="lazy" alt=""></div> <div class="c-article-recommendations-card__main"> <h3 class="c-article-recommendations-card__heading" itemprop="name headline"> <a class="c-article-recommendations-card__link" itemprop="url" href="https://link.springer.com/10.1134/S1990793120020207?fromPaywallRec=false" data-track="select_recommendations_1" data-track-context="inline recommendations" data-track-action="click recommendations inline - 1" data-track-label="10.1134/S1990793120020207">Vertical Propagation of Acoustic Gravity Waves from the Lower Atmosphere during a Solar Eclipse </a> </h3> <div class="c-article-meta-recommendations" data-test="recommendation-info"> <span class="c-article-meta-recommendations__item-type">Article</span> <span class="c-article-meta-recommendations__date">01 March 2020</span> </div> </div> </article> </div> <div class="c-article-recommendations-list__item"> <article class="c-article-recommendations-card" itemscope itemtype="http://schema.org/ScholarlyArticle"> <div class="c-article-recommendations-card__img"><img src="https://media.springernature.com/w215h120/springer-static/image/art%3Aplaceholder%2Fimages/placeholder-figure-springernature.png" loading="lazy" alt=""></div> <div class="c-article-recommendations-card__main"> <h3 class="c-article-recommendations-card__heading" itemprop="name headline"> <a class="c-article-recommendations-card__link" itemprop="url" href="https://link.springer.com/10.3103/S0884591316040024?fromPaywallRec=false" data-track="select_recommendations_2" data-track-context="inline recommendations" data-track-action="click recommendations inline - 2" data-track-label="10.3103/S0884591316040024">Wave processes in the ionosphere over Europe that accompanied the solar eclipse of March 20, 2015 </a> </h3> <div class="c-article-meta-recommendations" data-test="recommendation-info"> <span class="c-article-meta-recommendations__item-type">Article</span> <span class="c-article-meta-recommendations__date">01 July 2016</span> </div> </div> </article> </div> <div class="c-article-recommendations-list__item"> <article class="c-article-recommendations-card" itemscope itemtype="http://schema.org/ScholarlyArticle"> <div class="c-article-recommendations-card__img"><img src="https://media.springernature.com/w215h120/springer-static/image/art%3Aplaceholder%2Fimages/placeholder-figure-springernature.png" loading="lazy" alt=""></div> <div class="c-article-recommendations-card__main"> <h3 class="c-article-recommendations-card__heading" itemprop="name headline"> <a class="c-article-recommendations-card__link" itemprop="url" href="https://link.springer.com/10.1134/S199079311601005X?fromPaywallRec=false" data-track="select_recommendations_3" data-track-context="inline recommendations" data-track-action="click recommendations inline - 3" data-track-label="10.1134/S199079311601005X">Disturbances of the upper atmosphere and ionosphere caused by acoustic-gravity wave sources in the lower atmosphere </a> </h3> <div class="c-article-meta-recommendations" data-test="recommendation-info"> <span class="c-article-meta-recommendations__item-type">Article</span> <span class="c-article-meta-recommendations__date">01 January 2016</span> </div> </div> </article> </div> </div> </section> <script> window.dataLayer = window.dataLayer || []; window.dataLayer.push({ recommendations: { recommender: 'semantic', model: 'specter', policy_id: 'NA', timestamp: 1741862901, embedded_user: 'null' } }); </script> <div class="app-card-service" data-test="article-checklist-banner"> <div> <a class="app-card-service__link" data-track="click_presubmission_checklist" data-track-context="article page top of reading companion" data-track-category="pre-submission-checklist" data-track-action="clicked article page checklist banner test 2 old version" data-track-label="link" href="https://beta.springernature.com/pre-submission?journalId=10712" data-test="article-checklist-banner-link"> <span class="app-card-service__link-text">Use our pre-submission checklist</span> <svg class="app-card-service__link-icon" aria-hidden="true" focusable="false"><use xlink:href="#icon-eds-i-arrow-right-small"></use></svg> </a> <p class="app-card-service__description">Avoid common mistakes on your manuscript.</p> </div> <div class="app-card-service__icon-container"> <svg class="app-card-service__icon" aria-hidden="true" focusable="false"> <use xlink:href="#icon-eds-i-clipboard-check-medium"></use> </svg> </div> </div> <div class="main-content"> <div class="c-article-section__content c-article-section__content--separator"><p><b>Article Highlights</b></p></div><div class="c-article-section__content"> <ul class="u-list-style-bullet"> <li> <p>We present statistics of the median amplitude of medium-scale atmospheric gravity (AGW) waves near the mesopause</p> </li> <li> <p>The AGW statistics is compared with that of the traveling ionospheric disturbances (TID) at the height of F2 maximum</p> </li> <li> <p>Except a fall anomaly in September–December larger amplitudes of both AGW and TID occur in the dark-sky conditions</p> </li> <li> <p>During the fall anomaly the AGWs near the mesopause are practically suppressed</p> </li> <li> <p>The fall anomaly is associated with the fall transition in the atmospheric circulation</p> </li> <li> <p>A sharp change of the phase of semi-diurnal tides occurs during the fall transition</p> </li> </ul></div><section data-title="Introduction"><div class="c-article-section" id="Sec2-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec2"><span class="c-article-section__title-number">1 </span>Introduction</h2><div class="c-article-section__content" id="Sec2-content"><p>Atmospheric gravity waves (AGWs) are low-frequency atmospheric waves whose restoring force is buoyancy in the atmosphere, such that the compressional waves get a transverse component of air motion. These waves can exist at frequencies lower than the buoyancy or Brunt-Väisälä frequency, which in is given by</p><div id="Equ1" class="c-article-equation"><div class="c-article-equation__content"><span class="mathjax-tex">$$\omega_{b}^{2} = \frac{{\left( {\gamma - 1} \right)g^{2} }}{{u_{s}^{2} }}\left( {1 + \frac{\gamma }{\gamma - 1}\frac{{{\text{d}}H}}{{{\text{d}}z}}} \right)$$</span></div><div class="c-article-equation__number"> (1) </div></div><p>, where <i>γ</i> is the adiabatic index (ratio of specific heat at constant pressure to specific heat at constant volume), <i>g</i> is acceleration due to gravity, <i>u</i><sub><i>s</i></sub> is the speed of sound (<span class="mathjax-tex">${u}_{s}^{2}=\gamma gH$</span>, where <i>H</i> is the pressure scale height of the atmosphere), and the term in parentheses is a “gradient correction” (e.g., Jones and Georges <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1976" title="Jones RM, Georges TM (1976) Infrasound from convective storms. III. Propagation to the ionosphere. J Acoust Soc Am 59:765–779. 
 https://doi.org/10.1121/1.380942
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR16" id="ref-link-section-d31072165e763">1976</a>). In the Earth’s atmosphere, a typical value of the Brunt–Väisälä period is of the order of 5–15 min.</p><p>Terrestrial AGWs generated in the lower atmosphere are driven by volcanoes, earthquakes, tropospheric turbulence, stratospheric winds, and man-made explosions (Hunsucker <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1987" title="Hunsucker R (1987) The sources of gravity waves. Nature 328:204–205. 
 https://doi.org/10.1038/328204a0
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR14" id="ref-link-section-d31072165e769">1987</a>). The AGWs generated in the lower atmosphere propagate upward to the ionosphere, where they produce variations of the electron density observed as traveling ionospheric disturbances (TIDs). On the other hand, AGWs can be caused by intense ionospheric electric currents and auroral precipitation in the auroral zone (e.g., Hunsucker <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1982" title="Hunsucker RD (1982) Atmospheric gravity waves generated in the high- latitude ionosphere: a review. Rev Geophys 20(2):293–315. 
 https://doi.org/10.1029/RG020i002p00293
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR15" id="ref-link-section-d31072165e772">1982</a>). Thus, the AGWs play an essential role in atmospheric dynamics, energy transport, and the atmosphere–ionosphere coupling.</p><p>The amplitude of AGWs generally increases with altitude because of decreasing air density, and the great majority of AGW studies are based on the observations of TIDs at ionospheric heights. The instruments used in such studies include the global positioning system (GPS) network (Kotake et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2007" title="Kotake N, Otsuka Y, Ogawa T, Tsugawa T, Saito A (2007) Statistical study of medium-scale traveling ionospheric disturbances observed with the GPS networks in southern California. Earth Planet Sp 59(2):95–102. 
 https://doi.org/10.1186/bf03352681
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR18" id="ref-link-section-d31072165e778">2007</a>; Sherstyukov et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2018" title="Sherstyukov R, Akchurin A, Sherstyukov O (2018) Collocated ionosonde and dense GPS/GLONASS network measurements of mid-latitude MSTIDs. Adv Space Res 61(7):1717–1725. 
 https://doi.org/10.1016/j.asr.2017.11.026
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR32" id="ref-link-section-d31072165e781">2018</a>; Otsuka et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Otsuka Y, Shinbori A, Tsugawa T, Nishioka M (2021) Solar activity dependence of medium-scale traveling ionospheric disturbances using GPS receivers in Japan. Earth Planets Space 73:22. 
 https://doi.org/10.1186/s40623-020-01353-5
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR28" id="ref-link-section-d31072165e784">2021</a>; Oluwadare et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2022" title="Oluwadare TS, Jakowski N, Valladares CE, Akala AO-O, Abe OE, Alizadeh MM, Schuh H (2022) Climatology of medium-scale traveling ionospheric disturbances (MSTIDs) observed with GPS networks in the North African region. Pure Appl Geophys 179:2501–2522. 
 https://doi.org/10.1007/s00024-022-03028-6
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR26" id="ref-link-section-d31072165e787">2022</a>), SuperDARN radars (Bristow et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1996" title="Bristow W, Greenwald R, Villain J (1996) On the seasonal dependence of medium-scale atmospheric gravity waves in the upper atmosphere at high latitudes. J Geophys Res 101(A7):15685–15699. 
 https://doi.org/10.1029/96ja01010
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR4" id="ref-link-section-d31072165e790">1996</a>; Frissell et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2014" title="Frissell N, Baker J, Ruohoniemi J, Gerrard A, Miller E, Marini J et al (2014) Climatology of medium-scale traveling ionospheric disturbances observed by the midlatitude Blackstone SuperDARN radar. J Geophys Res Space 119(9):7679–7697. 
 https://doi.org/10.1002/2014ja019870
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR8" id="ref-link-section-d31072165e794">2014</a>; Hazeyama et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2022" title="Hazeyama W, Nishitani N, Hori T, Nakamura T, Perwitasari S (2022) Statistical study of seasonal and solar activity dependence of nighttime MSTIDs occurrence using the SuperDARN Hokkaido pair of radars. J Geophys Res Space 127:e2021JA029965. 
 https://doi.org/10.1029/2021JA029965
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR10" id="ref-link-section-d31072165e797">2022</a>), ionosondes (Kozlovsky et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2013" title="Kozlovsky A, Turunen T, Ulich T (2013) Rapid-run ionosonde observations of traveling ionospheric disturbances in the auroral ionosphere. J Geophys Res Space 118(8):5265–5276. 
 https://doi.org/10.1002/jgra.50474
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR19" id="ref-link-section-d31072165e800">2013</a>; Moges et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024a" title="Moges ST, Sherstyukov RO, Kozlovsky A, Ulich T, Lester M (2024a) Statistics of traveling ionospheric disturbances at high latitudes using a rapid-run ionosonde. J Geophys Res Space 129:e0230JA31694. 
 https://doi.org/10.1029/2023JA031694
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR22" id="ref-link-section-d31072165e803">2024a</a>, <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference b" title="Moges ST, Kozlovsky A, Sherstyukov RO, Ulich T (2024b) Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes. J Geophys Res Space 129:e2024JA033013. 
 https://doi.org/10.1029/2024JA033013
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR23" id="ref-link-section-d31072165e806">b</a>), and incoherent scatter radars (Kirchengast <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1997" title="Kirchengast G (1997) Characteristics of high-latitude TIDs from different causative mechanisms deduced by theoretical modeling. J Geophys Res 102(A3):4597–4612. 
 https://doi.org/10.1029/96ja03294
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR17" id="ref-link-section-d31072165e809">1997</a>; Vlasov et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2011" title="Vlasov A, Kauristie K, Van de Kamp M, Luntama J-P, Pogoreltsev A (2011) A study of traveling ionospheric disturbances and atmospheric gravity waves using EISCAT Svalbard Radar IPY-data. Ann Geophys 29(11):2101–2116. 
 https://doi.org/10.5194/angeo-29-2101-2011
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR37" id="ref-link-section-d31072165e813">2011</a>; Nygren et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2015" title="Nygren T, Aikio A, Voiculescu M, Cai L (2015) Radar observations of simultaneous traveling ionospheric disturbances and atmospheric gravity waves. J Geophys Res Space 120(5):3949–3960. 
 https://doi.org/10.1002/2014JA020794
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR25" id="ref-link-section-d31072165e816">2015</a>). In the last years, numerous studies were performed using GPS network, which have provided local time–seasonal distributions of TIDs and investigated dependences on the solar activity (Otsuka et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Otsuka Y, Shinbori A, Tsugawa T, Nishioka M (2021) Solar activity dependence of medium-scale traveling ionospheric disturbances using GPS receivers in Japan. Earth Planets Space 73:22. 
 https://doi.org/10.1186/s40623-020-01353-5
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR28" id="ref-link-section-d31072165e819">2021</a>; Oluwadare et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2022" title="Oluwadare TS, Jakowski N, Valladares CE, Akala AO-O, Abe OE, Alizadeh MM, Schuh H (2022) Climatology of medium-scale traveling ionospheric disturbances (MSTIDs) observed with GPS networks in the North African region. Pure Appl Geophys 179:2501–2522. 
 https://doi.org/10.1007/s00024-022-03028-6
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR26" id="ref-link-section-d31072165e822">2022</a>). These studies were focused on the medium-scale TIDs (MSTIDs) with periods of the order of 60 min, and mostly related to the altitudes 250–350 km which correspond to the maximum electron density in the F2 layer.</p><p>Studies of AGWs in the neutral atmosphere below ionospheric heights (below 90 km) are mostly based on lidar observations of the air temperature or velocity (e.g., Reichert et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2019" title="Reichert R, Kaifler B, Kaifler N, Rapp M, Pautet P-D, Taylor MJ, Kozlovsky A, Lester M, Kivi R (2019) Retrieval of intrinsic mesospheric gravity wave parameters using lidar and airglow temperature and meteor radar wind data. Atmos Meas Tech 12:5997–6015. 
 https://doi.org/10.5194/amt-12-5997-2019
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR31" id="ref-link-section-d31072165e828">2019</a>), which are practically impossible in sunlit sky conditions and strongly affected by cloudiness and transparency of the air. In particular, one lacks such observations at high latitudes in summertime during the polar day. Because of this, AGWs below 90 km are much less investigated than that at the heights of F2 ionospheric layer.</p><p>To monitor the neutral wind at 80–100 km, meteor radars (MRs) started to be widely used in the last two decades (Hocking et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2001" title="Hocking WK, Fuller B, Vandepeer B (2001) Real-time determination of meteor-related parameters utilizing modern digital technology. J Atmos Sol Terr Phys 63(2):155–169. 
 https://doi.org/10.1016/S1364-6826(00)00138-3
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR12" id="ref-link-section-d31072165e835">2001</a>). The physical basis behind these facilities is that meteoroids entering the Earth's atmosphere form ionized trails at heights between 80 and 100 km, which are transported by the wind and reflect radio waves. In the standard mode, a MR observing the position and radial velocity of several thousand trails per day provides the zonal and meridional components of the mean neutral wind at ∼3 km height intervals in the ∼200-km area with one-hour time resolution. Such a time resolution is not sufficient for detecting MSTIDs with periods of the order of 60 min.</p><p>However, the temporal and spatial resolution of meteor radars can be essentially improved by combining data from several neighboring radars. Such a network (called Nordic Meteor Radar Cluster) was established in Northern Europe in November 2019 (Stober et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Stober G, Kozlovsky A, Liu A, Qiao Z, Tsutsumi M, Hall C, Nozawa S, Lester M, Belova E, Kero J, Espy PJ, Hibbons RE, Mitchell N (2021) Atmospheric tomography using the Nordic meteor radar cluster and Chilean observation network de meteor radars: network details and 3DVAR retrieval. Atmos Meas Tech 14:6509–6532. 
 https://doi.org/10.5194/amt-14-6509-2021
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR35" id="ref-link-section-d31072165e841">2021</a>). This radar cluster can provide wind data with 10-min resolution, which was successfully utilized for detecting the AGW launched by the Tonga-Hunga volcanic eruption on 15 January 2022 (Stober et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2023" title="Stober G, Liu A, Kozlovsky A, Qiao Z, Krochin W, Shi G, Kero J et al (2023) Identifying gravity waves launched by the Hunga Tonga-Hunga Ha‘apai volcanic eruption in mesosphere/lower thermosphere winds derived from CONDOR and the Nordic Meteor Radar Cluster. Ann Geophys 41:197–208. 
 https://doi.org/10.5194/angeo-41-197-2023
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR36" id="ref-link-section-d31072165e844">2023</a>). Further, Günzkofer et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2023" title="Günzkofer F, Pokhotelov D, Stober G, Mann I, Vadas SL, Becker E, Tjulin A, Kozlovsky A, Tsutsumi M, Gulbrandsen N, Nozawa S, Lester M, Belova E, Kero J, Mitchell NJ, Borries C (2023) Inferring neutral winds in the ionospheric transition region from atmospheric-gravity-wave traveling-ionospheric-disturbance (AGW-TID) observations with the EISCAT VHF radar and the Nordic Meteor Radar Cluster. Ann Geophys 41:409–428. 
 https://doi.org/10.5194/angeo-41-409-2023
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR9" id="ref-link-section-d31072165e847">2023</a>) investigated three cases of ionospheric disturbances and AGWs simultaneously observed with the EISCAT radar and the Nordic meteor radar cluster. In the present paper we use the whole continuous four-years dataset of the Nordic meteor radar cluster to investigate statistics of medium-scale AGWs and make comparison with simultaneous MSTIDs retrieved from the co-located ionosonde at Sodankylä Geophysical Observatory. The results are discussed in view of generation mechanisms of AGWs and MSTIDs at auroral latitudes and physical links between the Earth atmosphere and ionosphere.</p></div></div></section><section data-title="Observations, Methods, and Data Presentation"><div class="c-article-section" id="Sec3-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec3"><span class="c-article-section__title-number">2 </span>Observations, Methods, and Data Presentation</h2><div class="c-article-section__content" id="Sec3-content"><p>The observations were made at high latitudes (67–70°N) in the Northern Europe in the area which statistically corresponds to the equatorward part of the nightside auroral oval (L-shell values 5.5–6.5). The 4-years dataset includes whole years 2020–2023. During this time the solar activity was rising, such that yearly mean sunspot numbers were 9, 30, 83, and 125 in years 2020, 2021, 2022, and 2023, respectively.</p><h3 class="c-article__sub-heading" id="Sec4"><span class="c-article-section__title-number">2.1 </span>Nordic Meteor Radar Cluster: AGW</h3><p>The Nordic meteor radar cluster (see map in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig1">1</a>) consists of four monostatic meteor radars located in Tromsø (TRO, 69.59°N, 19.2°E), Norway; Alta (ALT, 70.0°N, 23.3°E), Norway; Kiruna (KIR, 67.9°N, 21.1°E), Sweden; and Sodankylä (SOD, 67.4°N, 26.6°E), Finland. In this study we used the retrieval algorithm for multistatic meteor radar networks to obtain tomographic 3-D wind fields within a pre-defined domain area. This algorithm called 3D-Var is a part of the Agile Software for Gravity wAve Regional Dynamics (ASGARD) and based on the optimal estimation technique and Bayesian statistics (Stober et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Stober G, Kozlovsky A, Liu A, Qiao Z, Tsutsumi M, Hall C, Nozawa S, Lester M, Belova E, Kero J, Espy PJ, Hibbons RE, Mitchell N (2021) Atmospheric tomography using the Nordic meteor radar cluster and Chilean observation network de meteor radars: network details and 3DVAR retrieval. Atmos Meas Tech 14:6509–6532. 
 https://doi.org/10.5194/amt-14-6509-2021
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR35" id="ref-link-section-d31072165e868">2021</a>). Figure <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig1">1</a> shows an example of the horizontal wind field at 90 km retrieved using this algorithm.</p><div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-1" data-title="Fig. 1"><figure><figcaption><b id="Fig1" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 1</b></figcaption><div class="c-article-section__figure-content"><div class="c-article-section__figure-item"><a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/1" rel="nofollow"><picture><source type="image/webp" srcset="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig1_HTML.png?as=webp"><img aria-describedby="Fig1" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig1_HTML.png" alt="figure 1" loading="lazy" width="685" height="640"></picture></a></div><div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-1-desc"><p>An example of the horizontal wind field at 90 km retrieved from the Nordic Meteor Radar Cluster. The cluster consists of four monostatic meteor radars located in Tromsø (TRO), Alta (ALT), Kiruna (KIR), and Sodankylä (SOD). In the present study the AGWs were monitored in the area 90 × 90 km indicated by the square</p></div></div><div class="u-text-right u-hide-print"><a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/1" data-track-dest="link:Figure1 Full size image" aria-label="Full size image figure 1" rel="nofollow"><span>Full size image</span><svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small"></use></svg></a></div></figure></div><p>Using the 3D-Var algorithm, we calculated the horizontal wind vector in the area 90 × 90 km (indicated by the red square in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig1">1</a>) with a time resolution of 10 min and a height resolution of 5 km, which is suitable for detecting medium-scale AGW (Günzkofer et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2023" title="Günzkofer F, Pokhotelov D, Stober G, Mann I, Vadas SL, Becker E, Tjulin A, Kozlovsky A, Tsutsumi M, Gulbrandsen N, Nozawa S, Lester M, Belova E, Kero J, Mitchell NJ, Borries C (2023) Inferring neutral winds in the ionospheric transition region from atmospheric-gravity-wave traveling-ionospheric-disturbance (AGW-TID) observations with the EISCAT VHF radar and the Nordic Meteor Radar Cluster. Ann Geophys 41:409–428. 
 https://doi.org/10.5194/angeo-41-409-2023
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR9" id="ref-link-section-d31072165e897">2023</a>). In this area (centered at 69°N, 22°E) the largest total number of meteors are detected by the four radars, such that the wind data are the most reliable. The time series at each height were band-pass filtered by the 3-order Butterworth filter in 25–100 min period band, which corresponds to oscillation periods of the medium-scale AGW. Figure <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig2">2</a> shows an example of such wind data and oscillations in the zonal (U, panels a and b) and meridional (V, panels c and d) components of horizontal wind at 80–100 km for one day. A typical accuracy of the wind data at 90 km is of the order of 10 m/s. Then we found the amplitude of the oscillations in each one-hour bin, i.e., max(|U|) and max(|V|) at 90 km, where maximal number of meteors are detected and, hence, the wind data are the most reliable. In the following these time series are considered as hourly data of the AGW amplitude in the two components of horizontal wind at 90 km.</p><div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-2" data-title="Fig. 2"><figure><figcaption><b id="Fig2" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 2</b></figcaption><div class="c-article-section__figure-content"><div class="c-article-section__figure-item"><a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/2" rel="nofollow"><picture><source type="image/webp" srcset="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig2_HTML.png?as=webp"><img aria-describedby="Fig2" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig2_HTML.png" alt="figure 2" loading="lazy" width="685" height="849"></picture></a></div><div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-2-desc"><p>An example of wind data and medium-scale AGW in the zonal (U, panels <b>a</b> and <b>b</b>) and meridional (V, panels <b>c</b> and <b>d</b>) components of horizontal wind at 80–100 km for one day</p></div></div><div class="u-text-right u-hide-print"><a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/2" data-track-dest="link:Figure2 Full size image" aria-label="Full size image figure 2" rel="nofollow"><span>Full size image</span><svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small"></use></svg></a></div></figure></div><p>To obtain the season-local time (S-LT) statistics (i.e., monthly medians), we calculated median values of the AGW amplitude in each month for each hour of local time (in this area LT≈UT + 2). Thus, for each year we obtained two 12 × 24 matrixes representing S-LT distributions of the AGW amplitudes. These distributions are shown in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig3">3</a>, where the color coding in left and central panels shows amplitude of AGW in zonal and meridional components, respectively, and the right column show a ratio of the amplitudes (V/U). Four rows in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig3">3</a> correspond to the four years of the observations.</p><div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-3" data-title="Fig. 3"><figure><figcaption><b id="Fig3" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 3</b></figcaption><div class="c-article-section__figure-content"><div class="c-article-section__figure-item"><a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/3" rel="nofollow"><picture><source type="image/webp" srcset="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig3_HTML.png?as=webp"><img aria-describedby="Fig3" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig3_HTML.png" alt="figure 3" loading="lazy" width="685" height="788"></picture></a></div><div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-3-desc"><p>Seasonal-local time distribution of the AGW median amplitude (S-LT statistics) shown by the color coding. Left and central panels show the amplitude in zonal (U) and meridional (V) components, respectively, and the right column show a ratio of the amplitudes (V/U). Four rows correspond to the four years of the observations</p></div></div><div class="u-text-right u-hide-print"><a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/3" data-track-dest="link:Figure3 Full size image" aria-label="Full size image figure 3" rel="nofollow"><span>Full size image</span><svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small"></use></svg></a></div></figure></div><p>Qualitatively, the distributions are similar in all the years. The largest AGW amplitudes are observed in the zonal component in winter nighttime and a deep minimum occurs in summer daytime. The dominating zonal component is likely explained by the filtering effect, such that the AGWs propagating upward from the lower atmosphere tend to propagate horizontally against the direction of background wind (Hines and Reddy <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1967" title="Hines CO, Reddy CA (1967) On the propagation of atmospheric gravity waves through regions of wind shear. J Geophys Res 72(3):1015–1034. 
 https://doi.org/10.1029/JZ072i003p01015
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR11" id="ref-link-section-d31072165e962">1967</a>). Amplitudes of AGWs in the meridional wind are smaller than that in the zonal wind, except the spring and fall daytime when the meridional component is comparable with the zonal and even dominates in years 2022 and 2023, perhaps with the rising solar activity. In more details these and other features will be discussed below in comparison with the statistics of traveling ionospheric disturbances.</p><h3 class="c-article__sub-heading" id="Sec5"><span class="c-article-section__title-number">2.2 </span>Ionosonde: TID</h3><p>Data of traveling ionospheric disturbances were derived from the ionosonde operating at the Sodankylä Geophysical Observatory (SGO, 67.4°N, 26.6°E, corrected geomagnetic latitude 64°), co-located with the SOD meteor radar. It is a frequency‐modulated, continuous wave chirp ionosonde (0.5–16 MHz), which makes vertical sounding once a minute. More detailed descriptions of the SGO ionosonde are given by Kozlovsky et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2013" title="Kozlovsky A, Turunen T, Ulich T (2013) Rapid-run ionosonde observations of traveling ionospheric disturbances in the auroral ionosphere. J Geophys Res Space 118(8):5265–5276. 
 https://doi.org/10.1002/jgra.50474
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR19" id="ref-link-section-d31072165e973">2013</a>) and Enell et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2016" title="Enell C-F, Kozlovsky A, Turunen T, Ulich T, Välitalo S, Scotto C, Pezzopane M (2016) Comparison between manual scaling and Autoscala automatic scaling applied to Sodankylä geophysical observatory ionograms. Geosci Instrum Method Data Syst 5(1):53–64. 
 https://doi.org/10.5194/gi-5-53-2016
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR7" id="ref-link-section-d31072165e976">2016</a>). In the present study, we use the data of critical frequency foF2 obtained by the deep learning technique applied to the SGO ionograms collected during four years from 1 January 2020 through 31 December 2023. The deep learning technique for the analysis of SGO ionosonde data is described in Sherstyukov et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2023" title="Sherstyukov R, Kozlovsky A, Ulich T, Moges S (2023) Deep learning for ionogram parameters scaling at polar region ionosphere. In: 2023 XXXVTH general assembly and scientific symposium of the international union of radio science (URSI GASS), pp 1–4. 
 https://doi.org/10.23919/URSIGASS57860.2023.10265632
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR33" id="ref-link-section-d31072165e979">2023</a>, <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024" title="Sherstyukov R, Moges S, Kozlovsky A, Ulich T (2024) A deep learning approach for automatic ionogram parameters recognition with convolutional neural networks. Earth Space Sci 11:e2023EA003446. 
 https://doi.org/10.1029/2023EA003446
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR34" id="ref-link-section-d31072165e982">2024</a>).</p><p>The SGO ionosonde one-minute foF2 time series was analyzed in the same way as the meteor radars’ wind data presented above. Namely, the foF2 time series was band-pass filtered in the 25–100 min period band, and a maximal amplitude of the oscillations in each one-hour bin was taken to form a one-hour time series of medium-scale TID amplitude. Then, median values of the MSTID amplitude in each month for each hour of local time were calculated to obtain the S-LT statistics as a 12 × 24 matrix. These distributions of MSTID amplitudes (in units of plasma frequency, <i>A</i><sub>TID</sub> = ΔfoF2, MHz) for each year are shown by color coding in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig4">4</a> in left panels. White curves in the plots indicate times of the sunrise and sunset at 250 km above SGO, which corresponds to a typical height of the F2 layer.</p><div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-4" data-title="Fig. 4"><figure><figcaption><b id="Fig4" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 4</b></figcaption><div class="c-article-section__figure-content"><div class="c-article-section__figure-item"><a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/4" rel="nofollow"><picture><source type="image/webp" srcset="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig4_HTML.png?as=webp"><img aria-describedby="Fig4" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig4_HTML.png" alt="figure 4" loading="lazy" width="685" height="1154"></picture></a></div><div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-4-desc"><p>Seasonal-local time distribution of the MSTID median amplitude (S-LT statistics) shown by the color coding. Left panels show absolute amplitude (in units of plasma frequency, <i>A</i><sub>TID</sub> = ΔfoF2, MHz) and right panels show relative amplitude (divided by mean hourly foF2). Four rows correspond to the four years of the observations. White curves indicate times of the sunrise and sunset at 250 km above SGO</p></div></div><div class="u-text-right u-hide-print"><a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/4" data-track-dest="link:Figure4 Full size image" aria-label="Full size image figure 4" rel="nofollow"><span>Full size image</span><svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small"></use></svg></a></div></figure></div><p>In distinction from the wind data of meteor radars which are available without gaps, the ionosonde data of foF2 are often missing because of auroral ionization in the E-layer or absorption in the D layer at the latitude of SGO. One more reason for ionosonde data gaps is the medium-frequency broadcast (MF, 300 kHz—3 MHz) interference, which plays a role in the nighttime, especially during low solar activity. In the present study we calculated the MSTID amplitudes if the foF2 data were obtained for at least 40 min during an hour. Then, the S-LT statistics were considered only if data were obtained in this hour at least for ten days during the month. Because of this, there are data gaps in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig4">4</a>, e.g., in the nighttime in spring 2020 and 2021. A typical accuracy of the foF2 data is 0.13 MHz (Moges et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024a" title="Moges ST, Sherstyukov RO, Kozlovsky A, Ulich T, Lester M (2024a) Statistics of traveling ionospheric disturbances at high latitudes using a rapid-run ionosonde. J Geophys Res Space 129:e0230JA31694. 
 https://doi.org/10.1029/2023JA031694
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR22" id="ref-link-section-d31072165e1023">2024a</a>).</p><p>The left panels in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig4">4</a> show the largest amplitudes of MSTIDs in daytime (near noon) in October–February, some smaller amplitude increases in the nighttime in summer and near the evening terminator in spring. Comparing to the years 2020 and 2021, the amplitudes are noticeably larger in 2022 and 2023, which is obviously associated with rising the solar activity (yearly sunspot numbers, SSN, are given in the titles of the panels). Earlier Moges et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024a" title="Moges ST, Sherstyukov RO, Kozlovsky A, Ulich T, Lester M (2024a) Statistics of traveling ionospheric disturbances at high latitudes using a rapid-run ionosonde. J Geophys Res Space 129:e0230JA31694. 
 https://doi.org/10.1029/2023JA031694
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR22" id="ref-link-section-d31072165e1032">2024a</a>, <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference b" title="Moges ST, Kozlovsky A, Sherstyukov RO, Ulich T (2024b) Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes. J Geophys Res Space 129:e2024JA033013. 
 https://doi.org/10.1029/2024JA033013
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR23" id="ref-link-section-d31072165e1035">b</a>) performed a very similar study of MSTIDs in the SGO ionosonde data for the years 2007–2022, and key aspects of their climatology and S-LT statistics have been discussed there. Therefore, in the present paper we do not focus on the ionosonde MSTIDs data but use them mostly for comparison with the AGWs observed in the neutral wind.</p><p>The AGWs propagating in the ionosphere produce variations of the electron density the magnitude of which, <i>δN</i><sub><i>e</i>,</sub> is given by (Hooke <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1970" title="Hooke WH (1970) The ionospheric response to internal gravity waves: 1. The f2 region response. J Geophys Res 75(28):5535–5544. 
 https://doi.org/10.1029/JA075i028p05535
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR13" id="ref-link-section-d31072165e1049">1970</a>):</p><div id="Equ2" class="c-article-equation"><div class="c-article-equation__content"><span class="mathjax-tex">$$\frac{{\delta N_{e} }}{{N_{{e0}} }} = \left( {\frac{{{\text{u}} \cdot {\text{b}}}}{\omega }} \right)\left\{ {\left( {{\text{k}} \cdot {\text{b}}} \right) + i\left( {{\text{b}} \cdot {\text{z}}} \right)\left[ {\frac{1}{{2H}} + \frac{d}{{dz}}\left( {\ln N_{{e0}} } \right)} \right]} \right\},$$</span></div><div class="c-article-equation__number"> (2) </div></div><p>where <i>N</i><sub><i>e</i>0</sub> is an undisturbed (background) electron density, <b>u</b> is neutral atmosphere motions produced by an AGW having angular frequency ω and wave vector <b>k</b>, and <b>b</b> and <b>z</b> are unit vectors along the magnetic field and vertical, respectively. So far as the plasma frequency</p><div id="Equ3" class="c-article-equation"><div class="c-article-equation__content"><span class="mathjax-tex">$$\text{foF}2\propto \sqrt{{N}_{e}},$$</span></div><div class="c-article-equation__number"> (3) </div></div><p>to estimate the amplitude, <i>u</i><sub>max</sub>, of the AGWs caused the TIDs we use a relative TID amplitude calculated as</p><div id="Equ4" class="c-article-equation"><div class="c-article-equation__content"><span class="mathjax-tex">$$R_{{{\text{TID}}}} = \frac{2\Delta foF2}{{foF2}} \propto u_{\max }$$</span></div><div class="c-article-equation__number"> (4) </div></div><p>, where foF2 is a mean hourly value. A typical accuracy of the <i>R</i><sub>TID</sub> data is 7% (Moges et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024b" title="Moges ST, Kozlovsky A, Sherstyukov RO, Ulich T (2024b) Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes. J Geophys Res Space 129:e2024JA033013. 
 https://doi.org/10.1029/2024JA033013
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR23" id="ref-link-section-d31072165e1342">2024b</a>). In addition to AGWs, auroral precipitation and drifting ionospheric irregularities may contribute to variations of ionospheric electron density. However, these effects are important during auroral disturbances in which cases F layer is usually not observed because of absorption or blanketing and, hence, data of TID are not available. In practice (Moges et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024a" title="Moges ST, Sherstyukov RO, Kozlovsky A, Ulich T, Lester M (2024a) Statistics of traveling ionospheric disturbances at high latitudes using a rapid-run ionosonde. J Geophys Res Space 129:e0230JA31694. 
 https://doi.org/10.1029/2023JA031694
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR22" id="ref-link-section-d31072165e1345">2024a</a>, <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference b" title="Moges ST, Kozlovsky A, Sherstyukov RO, Ulich T (2024b) Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes. J Geophys Res Space 129:e2024JA033013. 
 https://doi.org/10.1029/2024JA033013
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR23" id="ref-link-section-d31072165e1349">b</a>) major contribution to the observed TIDs appears to be from the AGWs generated in the lower atmosphere or due to the ionospheric electrodynamics (referred as “auroral sources”).</p><p>Seasonal-local time distributions of the relative amplitude of MSTIDs are shown in the middle column in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig4">4</a>, where the white lines indicate times of the sunrise and sunset at the height of 250 km. The shape of the distributions is the same in all years, namely the relative amplitudes are large in the dark ionosphere and essentially smaller in the sunlight. In general, the relative amplitude in the dark time tends to slightly decrease with increasing solar activity. On the other hand, however, in the sunlight conditions <i>R</i><sub><i>TID</i></sub> was negligible during low solar activity in years 2020–2021, however with growing solar activity in 2022–2023 weak MSTIDs were observed in summertime near noon. For more details of the MSTID dependence on the solar activity we refer to Moges et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024b" title="Moges ST, Kozlovsky A, Sherstyukov RO, Ulich T (2024b) Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes. J Geophys Res Space 129:e2024JA033013. 
 https://doi.org/10.1029/2024JA033013
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR23" id="ref-link-section-d31072165e1364">2024b</a>).</p></div></div></section><section data-title="Data Analysis"><div class="c-article-section" id="Sec6-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec6"><span class="c-article-section__title-number">3 </span>Data Analysis</h2><div class="c-article-section__content" id="Sec6-content"><h3 class="c-article__sub-heading" id="Sec7"><span class="c-article-section__title-number">3.1 </span>Local Time—Seasonal Dependences of AGW and MSTID</h3><p>For comparison with the MSTIDs, Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig5">5</a>a shows monthly medians of the AGW amplitudes, <span class="mathjax-tex">${A}_{\text{AGW}}=\sqrt{{U}^{2}+{V}^{2}}$</span>, obtained from all four years of the observations, although here we used the data of meteor radars only when the ionosonde MSTID data were available. Respectively Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig5">5</a>b presents monthly medians of MSTID relative amplitudes for the same times. Noise levels for AGW and MSTID were estimated as 15 m/s and 7%, respectively. White curves in the plots indicate times of the sunrise and sunset at SGO near the height of F2 maximum to separate sunlight and dark-sky conditions.</p><div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-5" data-title="Fig. 5"><figure><figcaption><b id="Fig5" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 5</b></figcaption><div class="c-article-section__figure-content"><div class="c-article-section__figure-item"><a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/5" rel="nofollow"><picture><source type="image/webp" srcset="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig5_HTML.png?as=webp"><img aria-describedby="Fig5" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig5_HTML.png" alt="figure 5" loading="lazy" width="685" height="571"></picture></a></div><div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-5-desc"><p><b>a</b> Monthly medians of the AGW amplitudes obtained from all four years of the observations. <b>b</b> Monthly medians of MSTID relative amplitudes for the same times. <b>c</b> Ratio of the two amplitudes, <span class="mathjax-tex">${R}_{\text{TID}}/{A}_{\text{AGW}}$</span>. <b>d</b> Altitude of maximum of F2 layer (hmF2) according to the International Reference Ionosphere model for Sodankylä. White curves in the plots indicate times of the sunrise and sunset at 250 km above SGO to separate sunlight and dark-sky conditions. Noise levels for AGW and MSTID is of the order of 15 m/s and 7%, respectively</p></div></div><div class="u-text-right u-hide-print"><a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/5" data-track-dest="link:Figure5 Full size image" aria-label="Full size image figure 5" rel="nofollow"><span>Full size image</span><svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small"></use></svg></a></div></figure></div><p>To a rough approximation, both distributions look similar, showing minima (15–25 m/s and 2–7%, respectively) in the sunlight conditions and largest amplitudes (30–40 m/s and 10–15%, respectively) in the darkness. However, it is not the case in the fall (mid-September–mid-December, shown by vertical lines in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig5">5</a>a) when the amplitude of the AGW in the nighttime is as small as in the sunlight in summer. Thus, the AGW amplitude distribution shows a spring-fall asymmetry, whereas the relative amplitude distribution of MSTID is symmetrical with respect to the summer solstice. This feature is further shown in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig5">5</a>c, where a ratio of the two amplitudes, <span class="mathjax-tex">${R}_{\text{TID}}/{A}_{\text{AGW}}$</span>, is presented as an S-LT distribution. In most cases the ratio is nearly constant within 0.3 ± 0.1 units (%/m/s), except the fall nighttime (18–03 LT) when it may be as large as 0.5–0.7 units.</p><p>The spring-fall asymmetry of AGW amplitudes (a “fall anomaly”) is a systematic feature which is seen in all years in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig3">3</a> as well. Attempting to understand possible reasons for this phenomenon, we will consider annual variations of the neutral wind at 80–100 km (near the mesopause height), where the AGWs were shown.</p><h3 class="c-article__sub-heading" id="Sec8"><span class="c-article-section__title-number">3.2 </span>Background Conditions: Wind Near Mesopause</h3><p>To compare the monthly median amplitudes of the AGW and TID with the annual variations of the atmospheric circulation we used the horizontal wind data obtained from the monostatic meteor radar in Sodankylä. The left panels in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig6">6</a> show mean zonal wind averaged over ten days as a function of height between 80 and 100 km for the years 2020–2023, and central and right panels show monthly medians of the zonal and meridional wind components (S-LT distributions), respectively, at 90 km. The period of the fall anomaly, mid-September–mid-December, is indicated by vertical dashed lines in all the panels.</p><div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-6" data-title="Fig. 6"><figure><figcaption><b id="Fig6" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 6</b></figcaption><div class="c-article-section__figure-content"><div class="c-article-section__figure-item"><a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/6" rel="nofollow"><picture><source type="image/webp" srcset="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig6_HTML.png?as=webp"><img aria-describedby="Fig6" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs10712-025-09880-0/MediaObjects/10712_2025_9880_Fig6_HTML.png" alt="figure 6" loading="lazy" width="685" height="778"></picture></a></div><div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-6-desc"><p>Wind in the data of meteor radar in Sodankylä. Left panels show mean zonal wind (averaged over ten days) height profiles at 80–100 km; central and right panels show monthly medians of the zonal and meridional wind components (S-LT distributions), respectively, at 90 km. The period of fall anomaly, mid-September–mid-December, is indicated by vertical dashed lines. Four rows correspond to the four years of the observations</p></div></div><div class="u-text-right u-hide-print"><a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="/article/10.1007/s10712-025-09880-0/figures/6" data-track-dest="link:Figure6 Full size image" aria-label="Full size image figure 6" rel="nofollow"><span>Full size image</span><svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small"></use></svg></a></div></figure></div><p>In general, the yearly zonal wind patterns (left panels in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig6">6</a>) are the same in all years. In summer (May–August) the zonal wind is eastward above 90 km and westward below, such that a wind shear occurs at a height near 90 km. In winter the wind is predominantly eastward with highly variable magnitude. A gradual spring transition from the winter pattern to the summer one occurs in February-April when the zonal wind direction is changing to westward in the whole 80–100 km altitude range, and the date of this change may vary essentially from year to year indicating the spring transition in the global atmospheric circulation (Matthias et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Matthias V, Stober G, Kozlovsky A, Lester M, Belova E, Kero J (2021) Vertical structure of the Arctic spring transition in the middle atmosphere. J Geophys Res Atmos 126:e2020JD034353. 
 https://doi.org/10.1029/2020JD034353
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR21" id="ref-link-section-d31072165e1589">2021</a>). Distinct from the gradual spring transition, the fall transition occurs sharply at nearly the same time in mid-September in all four years. Remarkably, the fall transition coincides with the beginning of the fall anomaly in the AGW distribution.</p><p>Central and right panels in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig6">6</a> show that daily variations of the horizontal wind at 90 km are dominated by the semi-diurnal tides. The amplitude of the tides varies in the same way in all the years. Namely, there are two amplitude minima, in spring (in April) and in the fall (late October–early November). The spring minimum occurs during the spring transition and lasts longer than the fall one. The fall minimum is shorter although the phase of the tides also changes sharply, which is not observed in the spring. In fact, the phase drift starts in mid-September and ends in mid-December, such that it coincides with the fall anomaly in the AGW distribution.</p><p>Thus, we have found that the fall minima of medium-scale AGW near the mesopause (“fall anomaly” in mid-September–mid-December) starts with the fall transition in the atmospheric circulation and is associated with a sharp change of the phase of semi-diurnal tides.</p></div></div></section><section data-title="Interpretation and Discussion"><div class="c-article-section" id="Sec9-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec9"><span class="c-article-section__title-number">4 </span>Interpretation and Discussion</h2><div class="c-article-section__content" id="Sec9-content"><p>The main result of the present study is that, except the fall transition anomaly, the season-local time distributions of AGW at 90 km and MSTID at hmF2 are similar. Namely, larger amplitudes are observed in the dark-sky conditions, such that the separation between smaller and larger amplitudes occurs at solar terminator.</p><p>If the MSTIDs at hmF2 are caused by the AGWs propagating upward from the lower atmosphere, their amplitude distribution might be explained by the variations of the F2 maximum height (hmF2), which is elevated in the night. When AGWs propagate upward, the amplitude of the neutral wind oscillation due to AGWs increases with altitude to conserve kinetic energy, while the atmospheric density is decreasing with altitude as <span class="mathjax-tex">$\text{exp}\left(-z/H\right)$</span>. Indeed, the altitude hmF2 according to the International Reference Ionosphere model (Bilitza et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2022" title="Bilitza D, Pezzopane M, Truhlik V, Altadill D, Reinisch BW, Pignalberi A (2022) The international reference ionosphere model: a review and description of an ionospheric benchmark. Rev Geophys 60:e2022RG000792. 
 https://doi.org/10.1029/2022RG000792
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR3" id="ref-link-section-d31072165e1646">2022</a>) for Sodankylä shown in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig5">5</a>d seems to agree with this hypothesis. Namely, the nighttime hmF2 is about 340 km, whereas it is about 260 km in the sunlight conditions. Considering a scale height of the atmosphere at these heights of the order of 40 km, we get amplitudes of nighttime TIDs 2.7 times larger than daytime ones, assuming a constant amplitude of AGW in the lower atmosphere. However, such a mechanism fails to explain the amplitude distribution of AGW at a fixed height of 90 km (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig5">5</a>a).</p><p>Alternatively, one may assume that the AGWs generated in the lower atmosphere cannot propagate upward to the altitude of 90 km due to some special atmospheric conditions below during summer/daytime (in the sunlight). This can explain the AGW and MSTID minima in summertime due to the zonal wind shear occurring in May–September at about 90 km height (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig6">6</a> left panels). Moges et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024a" title="Moges ST, Sherstyukov RO, Kozlovsky A, Ulich T, Lester M (2024a) Statistics of traveling ionospheric disturbances at high latitudes using a rapid-run ionosonde. J Geophys Res Space 129:e0230JA31694. 
 https://doi.org/10.1029/2023JA031694
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR22" id="ref-link-section-d31072165e1661">2024a</a>) analyzed MSTID in the SGO ionosonde data and suggested that the low MSTID occurrence rate in summer could be associated with the zonal wind shear near mesopause. However, such an explanation is not suitable for the fall anomaly when the nighttime MSTIDs are observed at hmF2 (above 300 km) but corresponding AGWs do not occur at 90 km.</p><p>To explain the fall anomaly, we should assume that in the nighttime AGWs are generated above 90 km, e.g., due to the auroral activity as Hunsucker (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1982" title="Hunsucker RD (1982) Atmospheric gravity waves generated in the high- latitude ionosphere: a review. Rev Geophys 20(2):293–315. 
 https://doi.org/10.1029/RG020i002p00293
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR15" id="ref-link-section-d31072165e1667">1982</a>) suggested, and the configuration of neutral winds at that time does not allow the AGW propagation downward to the height of 90 km. It leads us to an idea that daytime and nighttime AGWs have different sources, in the lower atmosphere and in the ionosphere, respectively. In some sense, this is consistent with results of Otsuka (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Otsuka Y (2021) Medium-scale traveling ionospheric disturbances. In: Huang C, Lu G, Zhang Y, Paxton LJ (ed) Ionosphere dynamics and applications. 
 https://doi.org/10.1002/9781119815617.ch18
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR27" id="ref-link-section-d31072165e1670">2021</a>) and Otsuka et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Otsuka Y, Shinbori A, Tsugawa T, Nishioka M (2021) Solar activity dependence of medium-scale traveling ionospheric disturbances using GPS receivers in Japan. Earth Planets Space 73:22. 
 https://doi.org/10.1186/s40623-020-01353-5
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR28" id="ref-link-section-d31072165e1673">2021</a>) who studied statistics of the MSTID activity and propagation direction of MSTIDs at mid-latitudes and concluded that daytime MSTIDs could be caused by atmospheric gravity waves, and that nighttime MSTIDs were caused by electrodynamical forces, such as the Perkins instability (Perkins <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1973" title="Perkins F (1973) Spread F and ionospheric currents. J Geophys Res 78:218–226. 
 https://doi.org/10.1029/JA078i001p00218
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR29" id="ref-link-section-d31072165e1676">1973</a>).</p><p>Comparing with mid-latitudes, electrodynamical forces are even more important at auroral latitudes, where the observations of the present study were made. Solar wind energy is transferred through magnetosphere-ionosphere processes into the thermosphere, and the largest portion of this energy input occur in the auroral zone by means of auroral precipitation and ionospheric electric currents (Ahn et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1983" title="Ahn B-H, Akasofu S-I, Kamide Y (1983) The Joule heat production rate and the particle energy injection rate as a function of the geomagnetic indices AE and AL. J Geophys Res 88(A8):6275–6287. 
 https://doi.org/10.1029/JA088iA08p06275
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR1" id="ref-link-section-d31072165e1683">1983</a>). Aikio et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2012" title="Aikio AT, Cai L, Nygrén T (2012) Statistical distribution of height-integrated energy exchange rates in the ionosphere. J Geophys Res 117:A10325. 
 https://doi.org/10.1029/2012JA018078
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR2" id="ref-link-section-d31072165e1686">2012</a>) used the EISCAT radar in Tromsø (i.e., in the region of the present observations) to estimate statistics of electromagnetic energy transfer to the ionosphere and found that the energy input is predominantly in the night, but with increasing geomagnetic activity it becomes significant in the daytime as well. The peak altitude of Joule heating was found in the E region at 115–120 km, and the altitude range, where the electromagnetic energy of magnetospheric origin is converted to the mechanical energy of the neutrals is 20–35 km wide (Cai et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2013" title="Cai L, Aikio AT, Nygrén T (2013) Height-dependent energy exchange rates in the high-latitude E region ionosphere. J Geophys Res Space 118:7369–7383. 
 https://doi.org/10.1002/2013JA019195
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR5" id="ref-link-section-d31072165e1689">2013</a>). In a massive statistical study of electron precipitation with nine-years of low-orbit satellite data Newell et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1996" title="Newell P, Meng C-I, Lyons K (1996) Suppression of discrete aurorae by sunlight. Nature 381:766–767. 
 https://doi.org/10.1038/381766A0
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR24" id="ref-link-section-d31072165e1692">1996</a>) have shown that ionospheric conductivity is the key factor controlling the occurrence of discrete aurorae, such that discrete auroral arcs and associated intense ionospheric currents are preferably generated in the dark-sky conditions due to the ionospheric feedback instability. This is one more argument in favor of electrodynamical origin of AGWs in the winter and nightside.</p><p>As it was shown above (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig3">3</a>), AGWs at 90 km predominantly occur in the zonal wind component, except for the spring and fall daytime when the oscillations in the meridional component are significant and their amplitude increases with solar activity. The same tendency is observed in the amplitudes of daytime MSTIDs in left panels in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig4">4</a>. Also, Moges et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2024b" title="Moges ST, Kozlovsky A, Sherstyukov RO, Ulich T (2024b) Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes. J Geophys Res Space 129:e2024JA033013. 
 https://doi.org/10.1029/2024JA033013
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR23" id="ref-link-section-d31072165e1704">2024b</a>) used the SGO ionosonde data to study the solar activity dependence of MSTIDs with accounting variations of the height of F2 maximum, where the MSTIDs were detected. They inferred two likely mechanisms of MSTIDs, AGWs from the lower atmosphere and auroral sources. The later one shows an increase with the solar activity, and it was found more significant in the afternoon in winter and equinoxes. So far as geomagnetic activity increases with the solar activity, this observation is consistent with Aikio et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2012" title="Aikio AT, Cai L, Nygrén T (2012) Statistical distribution of height-integrated energy exchange rates in the ionosphere. J Geophys Res 117:A10325. 
 https://doi.org/10.1029/2012JA018078
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR2" id="ref-link-section-d31072165e1707">2012</a>) who found that the input of electromagnetic energy into ionosphere during daytime becomes significant and increases with increasing geomagnetic activity. Also, this observation leads to the suggestion that dayside AGWs, which are generated due to electrodynamical forces, are manifested in the meridional wind component and, hence, propagate along the north–south direction.</p><p>Thus, results of the present study are consistent with the idea that the AGWs observed near the mesopause may be generated due to turbulence in the lower atmosphere (below) or due to electrodynamical forces and auroral activity in the ionospheric E-layer. The latter is more important in the dark-sky conditions. In such a case, the suppression of AGWs at 90 km altitude in the autumn during nighttime may be due to special atmospheric conditions above, between 90 and 120 km, which are associated with the fall transition in the global atmospheric circulation.</p><p>The atmospheric fall transition is manifested in the phase change of semi-diurnal tides (S2) and their amplitude decrease (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/article/10.1007/s10712-025-09880-0#Fig6">6</a>). This phenomenon was already known earlier (e.g., Riggin et al. <a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2003" title="Riggin D, Meyer C, Fritts D, Jarvis M, Murayama Y, Singer W, Vincent R, Murphy D (2003) MF radar observations of seasonal variability of semidiurnal motions in the mesosphere at high northern and southern latitudes. J Atmos Sol Terr Phys 65:483–493. 
 https://doi.org/10.1016/S1364-6826(02)00340-1
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR30" id="ref-link-section-d31072165e1719">2003</a>). Conte et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2018" title="Conte JF, Chau JL, Laskar FI, Stober G, Schmidt H, Brown P (2018) Semidiurnal solar tide differences between fall and spring transition times in the Northern Hemisphere. Ann Geophys 36(4):999–1008. 
 https://doi.org/10.5194/angeo-36-999-2018
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR6" id="ref-link-section-d31072165e1722">2018</a>) suggested that the change seen in the phase of S2 during the fall transition may result from interactions between this tide and gravity waves. However, possible mechanisms of such interactions are still unclear. Thus, we may consider the S2 phase change as a manifestation of the fall transition, whereas the fall transition itself is a complex of global changes in the atmosphere. Peculiarities of the atmospheric dynamics and vertical propagation of AGWs during the fall transition were recently presented in a case study by Günzkofer et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2023" title="Günzkofer F, Pokhotelov D, Stober G, Mann I, Vadas SL, Becker E, Tjulin A, Kozlovsky A, Tsutsumi M, Gulbrandsen N, Nozawa S, Lester M, Belova E, Kero J, Mitchell NJ, Borries C (2023) Inferring neutral winds in the ionospheric transition region from atmospheric-gravity-wave traveling-ionospheric-disturbance (AGW-TID) observations with the EISCAT VHF radar and the Nordic Meteor Radar Cluster. Ann Geophys 41:409–428. 
 https://doi.org/10.5194/angeo-41-409-2023
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR9" id="ref-link-section-d31072165e1725">2023</a>). They considered three cases of MSTID observed at the EISCAT (at heights 110–170 km) and simultaneous AGW at Nordic Meteor Radar Cluster (at heights 80–100 km) during daytime (10–16 LT) in July, September, and October, and found that the wave characteristics of traveling ionospheric disturbances are notably impacted by the fall transition of the mesosphere and lower thermosphere. In the present study we used much larger statistics and show that the fall effect is even more prominent in the night, and it systematically occurs during mid-September – mid-December. Further, some unusual effect in the ionospheric D-layer during fall transition, i.e., a spring-fall asymmetry, was found by Macotela et al. (<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2021" title="Macotela EL, Clilverd M, Renkwitz T, Chau J, Manninen J, Banyś D (2021) Spring-fall asymmetry in VLF amplitudes recorded in the North Atlantic region: The fall-effect. Geophys Res Lett 48:e2021GL094581. 
 https://doi.org/10.1029/2021GL094581
 
 " href="/article/10.1007/s10712-025-09880-0#ref-CR20" id="ref-link-section-d31072165e1728">2021</a>) in a statistical study of the VLF radio waves propagation. Indeed, it looks like the fall transition is associated with an essential anomaly in the mesosphere-low thermosphere region. Obviously, the fall transition deserves a more extensive consideration, which is however not feasible in the present paper.</p></div></div></section><section data-title="Conclusions"><div class="c-article-section" id="Sec10-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec10"><span class="c-article-section__title-number">5 </span>Conclusions</h2><div class="c-article-section__content" id="Sec10-content"><p>In the present paper we study the medium-scale AGWs with periods 25–100 min observed as variations of the horizontal wind at a height about 90 km (near mesopause) and medium-scale TIDs observed as relative variations of the electron density (i.e., ∆foF2/foF2) at the maximum of F2 layer, at 250–350 km. The observations were made at high latitudes corresponding to the equatorial part of the nightside auroral oval. We present four-years (2020–2023) statistics of monthly median amplitudes of the AGW and TID (i.e., season-local time distributions) of them.</p><p>The main result of the study is that, except the “fall anomaly” in mid-September–mid-December, the season-local time distributions of AGW at 90 km and MSTID at hmF2 are similar. Namely, larger amplitudes are observed in the dark-skydark-sky conditions, such that the separation between smaller and larger amplitudes occurs at solar terminator.</p><p>We have found that the fall minima of medium-scale AGW near the mesopause (“fall anomaly” in mid-September–mid-December) starts with the fall transition in the atmospheric circulation and is associated with a sharp change of the phase of semi-diurnal tides. At that time amplitude of MSTID at hmE2 are the same as in springtime, however AGWs at 90 km are practically suppressed. Thus, there is an asymmetry between spring and fall atmospheric transitions, which is clearly seen in the AGW and neutral winds in the mesosphere–low thermosphere region, however such an asymmetry is not manifested (or essentially less prominent) in the amplitudes of MSTID at the maximum of F2 layer.</p><p>The results are consistent with the idea that the AGWs observed near the mesopause may be generated due to turbulence in the lower atmosphere (below) or due to electrodynamical forces and auroral activity in the ionospheric E-layer. The latter is more important in the dark-sky conditions. In such a case, the suppression of AGWs at 90 km altitude in the autumn during nighttime may be due to special atmospheric conditions above, between 90 and 120 km, which are associated with the fall transition in the global atmospheric circulation.</p></div></div></section> </div> <div id="MagazineFulltextArticleBodySuffix"><section aria-labelledby="Bib1" data-title="References"><div class="c-article-section" id="Bib1-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Bib1">References</h2><div class="c-article-section__content" id="Bib1-content"><div data-container-section="references"><ul class="c-article-references" data-track-component="outbound reference" data-track-context="references section"><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR1">Ahn B-H, Akasofu S-I, Kamide Y (1983) The Joule heat production rate and the particle energy injection rate as a function of the geomagnetic indices AE and AL. J Geophys Res 88(A8):6275–6287. <a href="https://doi.org/10.1029/JA088iA08p06275" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/JA088iA08p06275">https://doi.org/10.1029/JA088iA08p06275</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/JA088iA08p06275" data-track-item_id="10.1029/JA088iA08p06275" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2FJA088iA08p06275" aria-label="Article reference 1" data-doi="10.1029/JA088iA08p06275">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 1" href="http://scholar.google.com/scholar_lookup?&title=The%20Joule%20heat%20production%20rate%20and%20the%20particle%20energy%20injection%20rate%20as%20a%20function%20of%20the%20geomagnetic%20indices%20AE%20and%20AL&journal=J%20Geophys%20Res&doi=10.1029%2FJA088iA08p06275&volume=88&issue=A8&pages=6275-6287&publication_year=1983&author=Ahn%2CB-H&author=Akasofu%2CS-I&author=Kamide%2CY"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR2">Aikio AT, Cai L, Nygrén T (2012) Statistical distribution of height-integrated energy exchange rates in the ionosphere. J Geophys Res 117:A10325. <a href="https://doi.org/10.1029/2012JA018078" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2012JA018078">https://doi.org/10.1029/2012JA018078</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2012JA018078" data-track-item_id="10.1029/2012JA018078" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2012JA018078" aria-label="Article reference 2" data-doi="10.1029/2012JA018078">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 2" href="http://scholar.google.com/scholar_lookup?&title=Statistical%20distribution%20of%20height-integrated%20energy%20exchange%20rates%20in%20the%20ionosphere&journal=J%20Geophys%20Res&doi=10.1029%2F2012JA018078&volume=117&publication_year=2012&author=Aikio%2CAT&author=Cai%2CL&author=Nygr%C3%A9n%2CT"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR3">Bilitza D, Pezzopane M, Truhlik V, Altadill D, Reinisch BW, Pignalberi A (2022) The international reference ionosphere model: a review and description of an ionospheric benchmark. Rev Geophys 60:e2022RG000792. <a href="https://doi.org/10.1029/2022RG000792" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2022RG000792">https://doi.org/10.1029/2022RG000792</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2022RG000792" data-track-item_id="10.1029/2022RG000792" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2022RG000792" aria-label="Article reference 3" data-doi="10.1029/2022RG000792">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 3" href="http://scholar.google.com/scholar_lookup?&title=The%20international%20reference%20ionosphere%20model%3A%20a%20review%20and%20description%20of%20an%20ionospheric%20benchmark&journal=Rev%20Geophys&doi=10.1029%2F2022RG000792&volume=60&publication_year=2022&author=Bilitza%2CD&author=Pezzopane%2CM&author=Truhlik%2CV&author=Altadill%2CD&author=Reinisch%2CBW&author=Pignalberi%2CA"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR4">Bristow W, Greenwald R, Villain J (1996) On the seasonal dependence of medium-scale atmospheric gravity waves in the upper atmosphere at high latitudes. J Geophys Res 101(A7):15685–15699. <a href="https://doi.org/10.1029/96ja01010" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/96ja01010">https://doi.org/10.1029/96ja01010</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/96ja01010" data-track-item_id="10.1029/96ja01010" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F96ja01010" aria-label="Article reference 4" data-doi="10.1029/96ja01010">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 4" href="http://scholar.google.com/scholar_lookup?&title=On%20the%20seasonal%20dependence%20of%20medium-scale%20atmospheric%20gravity%20waves%20in%20the%20upper%20atmosphere%20at%20high%20latitudes&journal=J%20Geophys%20Res&doi=10.1029%2F96ja01010&volume=101&issue=A7&pages=15685-15699&publication_year=1996&author=Bristow%2CW&author=Greenwald%2CR&author=Villain%2CJ"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR5">Cai L, Aikio AT, Nygrén T (2013) Height-dependent energy exchange rates in the high-latitude E region ionosphere. J Geophys Res Space 118:7369–7383. <a href="https://doi.org/10.1002/2013JA019195" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1002/2013JA019195">https://doi.org/10.1002/2013JA019195</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/2013JA019195" data-track-item_id="10.1002/2013JA019195" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1002%2F2013JA019195" aria-label="Article reference 5" data-doi="10.1002/2013JA019195">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 5" href="http://scholar.google.com/scholar_lookup?&title=Height-dependent%20energy%20exchange%20rates%20in%20the%20high-latitude%20E%20region%20ionosphere&journal=J%20Geophys%20Res%20Space&doi=10.1002%2F2013JA019195&volume=118&pages=7369-7383&publication_year=2013&author=Cai%2CL&author=Aikio%2CAT&author=Nygr%C3%A9n%2CT"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR6">Conte JF, Chau JL, Laskar FI, Stober G, Schmidt H, Brown P (2018) Semidiurnal solar tide differences between fall and spring transition times in the Northern Hemisphere. Ann Geophys 36(4):999–1008. <a href="https://doi.org/10.5194/angeo-36-999-2018" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.5194/angeo-36-999-2018">https://doi.org/10.5194/angeo-36-999-2018</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.5194/angeo-36-999-2018" data-track-item_id="10.5194/angeo-36-999-2018" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.5194%2Fangeo-36-999-2018" aria-label="Article reference 6" data-doi="10.5194/angeo-36-999-2018">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 6" href="http://scholar.google.com/scholar_lookup?&title=Semidiurnal%20solar%20tide%20differences%20between%20fall%20and%20spring%20transition%20times%20in%20the%20Northern%20Hemisphere&journal=Ann%20Geophys&doi=10.5194%2Fangeo-36-999-2018&volume=36&issue=4&pages=999-1008&publication_year=2018&author=Conte%2CJF&author=Chau%2CJL&author=Laskar%2CFI&author=Stober%2CG&author=Schmidt%2CH&author=Brown%2CP"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR7">Enell C-F, Kozlovsky A, Turunen T, Ulich T, Välitalo S, Scotto C, Pezzopane M (2016) Comparison between manual scaling and Autoscala automatic scaling applied to Sodankylä geophysical observatory ionograms. Geosci Instrum Method Data Syst 5(1):53–64. <a href="https://doi.org/10.5194/gi-5-53-2016" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.5194/gi-5-53-2016">https://doi.org/10.5194/gi-5-53-2016</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.5194/gi-5-53-2016" data-track-item_id="10.5194/gi-5-53-2016" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.5194%2Fgi-5-53-2016" aria-label="Article reference 7" data-doi="10.5194/gi-5-53-2016">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 7" href="http://scholar.google.com/scholar_lookup?&title=Comparison%20between%20manual%20scaling%20and%20Autoscala%20automatic%20scaling%20applied%20to%20Sodankyl%C3%A4%20geophysical%20observatory%20ionograms&journal=Geosci%20Instrum%20Method%20Data%20Syst&doi=10.5194%2Fgi-5-53-2016&volume=5&issue=1&pages=53-64&publication_year=2016&author=Enell%2CC-F&author=Kozlovsky%2CA&author=Turunen%2CT&author=Ulich%2CT&author=V%C3%A4litalo%2CS&author=Scotto%2CC&author=Pezzopane%2CM"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR8">Frissell N, Baker J, Ruohoniemi J, Gerrard A, Miller E, Marini J et al (2014) Climatology of medium-scale traveling ionospheric disturbances observed by the midlatitude Blackstone SuperDARN radar. J Geophys Res Space 119(9):7679–7697. <a href="https://doi.org/10.1002/2014ja019870" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1002/2014ja019870">https://doi.org/10.1002/2014ja019870</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/2014ja019870" data-track-item_id="10.1002/2014ja019870" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1002%2F2014ja019870" aria-label="Article reference 8" data-doi="10.1002/2014ja019870">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 8" href="http://scholar.google.com/scholar_lookup?&title=Climatology%20of%20medium-scale%20traveling%20ionospheric%20disturbances%20observed%20by%20the%20midlatitude%20Blackstone%20SuperDARN%20radar&journal=J%20Geophys%20Res%20Space&doi=10.1002%2F2014ja019870&volume=119&issue=9&pages=7679-7697&publication_year=2014&author=Frissell%2CN&author=Baker%2CJ&author=Ruohoniemi%2CJ&author=Gerrard%2CA&author=Miller%2CE&author=Marini%2CJ"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR9">Günzkofer F, Pokhotelov D, Stober G, Mann I, Vadas SL, Becker E, Tjulin A, Kozlovsky A, Tsutsumi M, Gulbrandsen N, Nozawa S, Lester M, Belova E, Kero J, Mitchell NJ, Borries C (2023) Inferring neutral winds in the ionospheric transition region from atmospheric-gravity-wave traveling-ionospheric-disturbance (AGW-TID) observations with the EISCAT VHF radar and the Nordic Meteor Radar Cluster. Ann Geophys 41:409–428. <a href="https://doi.org/10.5194/angeo-41-409-2023" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.5194/angeo-41-409-2023">https://doi.org/10.5194/angeo-41-409-2023</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.5194/angeo-41-409-2023" data-track-item_id="10.5194/angeo-41-409-2023" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.5194%2Fangeo-41-409-2023" aria-label="Article reference 9" data-doi="10.5194/angeo-41-409-2023">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 9" href="http://scholar.google.com/scholar_lookup?&title=Inferring%20neutral%20winds%20in%20the%20ionospheric%20transition%20region%20from%20atmospheric-gravity-wave%20traveling-ionospheric-disturbance%20%28AGW-TID%29%20observations%20with%20the%20EISCAT%20VHF%20radar%20and%20the%20Nordic%20Meteor%20Radar%20Cluster&journal=Ann%20Geophys&doi=10.5194%2Fangeo-41-409-2023&volume=41&pages=409-428&publication_year=2023&author=G%C3%BCnzkofer%2CF&author=Pokhotelov%2CD&author=Stober%2CG&author=Mann%2CI&author=Vadas%2CSL&author=Becker%2CE&author=Tjulin%2CA&author=Kozlovsky%2CA&author=Tsutsumi%2CM&author=Gulbrandsen%2CN&author=Nozawa%2CS&author=Lester%2CM&author=Belova%2CE&author=Kero%2CJ&author=Mitchell%2CNJ&author=Borries%2CC"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR10">Hazeyama W, Nishitani N, Hori T, Nakamura T, Perwitasari S (2022) Statistical study of seasonal and solar activity dependence of nighttime MSTIDs occurrence using the SuperDARN Hokkaido pair of radars. J Geophys Res Space 127:e2021JA029965. <a href="https://doi.org/10.1029/2021JA029965" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2021JA029965">https://doi.org/10.1029/2021JA029965</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2021JA029965" data-track-item_id="10.1029/2021JA029965" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2021JA029965" aria-label="Article reference 10" data-doi="10.1029/2021JA029965">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 10" href="http://scholar.google.com/scholar_lookup?&title=Statistical%20study%20of%20seasonal%20and%20solar%20activity%20dependence%20of%20nighttime%20MSTIDs%20occurrence%20using%20the%20SuperDARN%20Hokkaido%20pair%20of%20radars&journal=J%20Geophys%20Res%20Space&doi=10.1029%2F2021JA029965&volume=127&publication_year=2022&author=Hazeyama%2CW&author=Nishitani%2CN&author=Hori%2CT&author=Nakamura%2CT&author=Perwitasari%2CS"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR11">Hines CO, Reddy CA (1967) On the propagation of atmospheric gravity waves through regions of wind shear. J Geophys Res 72(3):1015–1034. <a href="https://doi.org/10.1029/JZ072i003p01015" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/JZ072i003p01015">https://doi.org/10.1029/JZ072i003p01015</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/JZ072i003p01015" data-track-item_id="10.1029/JZ072i003p01015" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2FJZ072i003p01015" aria-label="Article reference 11" data-doi="10.1029/JZ072i003p01015">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 11" href="http://scholar.google.com/scholar_lookup?&title=On%20the%20propagation%20of%20atmospheric%20gravity%20waves%20through%20regions%20of%20wind%20shear&journal=J%20Geophys%20Res&doi=10.1029%2FJZ072i003p01015&volume=72&issue=3&pages=1015-1034&publication_year=1967&author=Hines%2CCO&author=Reddy%2CCA"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR12">Hocking WK, Fuller B, Vandepeer B (2001) Real-time determination of meteor-related parameters utilizing modern digital technology. J Atmos Sol Terr Phys 63(2):155–169. <a href="https://doi.org/10.1016/S1364-6826(00)00138-3" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1016/S1364-6826(00)00138-3">https://doi.org/10.1016/S1364-6826(00)00138-3</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/S1364-6826(00)00138-3" data-track-item_id="10.1016/S1364-6826(00)00138-3" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1016%2FS1364-6826%2800%2900138-3" aria-label="Article reference 12" data-doi="10.1016/S1364-6826(00)00138-3">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 12" href="http://scholar.google.com/scholar_lookup?&title=Real-time%20determination%20of%20meteor-related%20parameters%20utilizing%20modern%20digital%20technology&journal=J%20Atmos%20Sol%20Terr%20Phys&doi=10.1016%2FS1364-6826%2800%2900138-3&volume=63&issue=2&pages=155-169&publication_year=2001&author=Hocking%2CWK&author=Fuller%2CB&author=Vandepeer%2CB"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR13">Hooke WH (1970) The ionospheric response to internal gravity waves: 1. The f2 region response. J Geophys Res 75(28):5535–5544. <a href="https://doi.org/10.1029/JA075i028p05535" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/JA075i028p05535">https://doi.org/10.1029/JA075i028p05535</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/JA075i028p05535" data-track-item_id="10.1029/JA075i028p05535" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2FJA075i028p05535" aria-label="Article reference 13" data-doi="10.1029/JA075i028p05535">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 13" href="http://scholar.google.com/scholar_lookup?&title=The%20ionospheric%20response%20to%20internal%20gravity%20waves%3A%201.%20The%20f2%20region%20response&journal=J%20Geophys%20Res&doi=10.1029%2FJA075i028p05535&volume=75&issue=28&pages=5535-5544&publication_year=1970&author=Hooke%2CWH"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR14">Hunsucker R (1987) The sources of gravity waves. Nature 328:204–205. <a href="https://doi.org/10.1038/328204a0" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1038/328204a0">https://doi.org/10.1038/328204a0</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/328204a0" data-track-item_id="10.1038/328204a0" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1038%2F328204a0" aria-label="Article reference 14" data-doi="10.1038/328204a0">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 14" href="http://scholar.google.com/scholar_lookup?&title=The%20sources%20of%20gravity%20waves&journal=Nature&doi=10.1038%2F328204a0&volume=328&pages=204-205&publication_year=1987&author=Hunsucker%2CR"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR15">Hunsucker RD (1982) Atmospheric gravity waves generated in the high- latitude ionosphere: a review. Rev Geophys 20(2):293–315. <a href="https://doi.org/10.1029/RG020i002p00293" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/RG020i002p00293">https://doi.org/10.1029/RG020i002p00293</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/RG020i002p00293" data-track-item_id="10.1029/RG020i002p00293" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2FRG020i002p00293" aria-label="Article reference 15" data-doi="10.1029/RG020i002p00293">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 15" href="http://scholar.google.com/scholar_lookup?&title=Atmospheric%20gravity%20waves%20generated%20in%20the%20high-%20latitude%20ionosphere%3A%20a%20review&journal=Rev%20Geophys&doi=10.1029%2FRG020i002p00293&volume=20&issue=2&pages=293-315&publication_year=1982&author=Hunsucker%2CRD"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR16">Jones RM, Georges TM (1976) Infrasound from convective storms. III. Propagation to the ionosphere. J Acoust Soc Am 59:765–779. <a href="https://doi.org/10.1121/1.380942" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1121/1.380942">https://doi.org/10.1121/1.380942</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1121/1.380942" data-track-item_id="10.1121/1.380942" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1121%2F1.380942" aria-label="Article reference 16" data-doi="10.1121/1.380942">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 16" href="http://scholar.google.com/scholar_lookup?&title=Infrasound%20from%20convective%20storms.%20III.%20Propagation%20to%20the%20ionosphere&journal=J%20Acoust%20Soc%20Am&doi=10.1121%2F1.380942&volume=59&pages=765-779&publication_year=1976&author=Jones%2CRM&author=Georges%2CTM"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR17">Kirchengast G (1997) Characteristics of high-latitude TIDs from different causative mechanisms deduced by theoretical modeling. J Geophys Res 102(A3):4597–4612. <a href="https://doi.org/10.1029/96ja03294" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/96ja03294">https://doi.org/10.1029/96ja03294</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/96ja03294" data-track-item_id="10.1029/96ja03294" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F96ja03294" aria-label="Article reference 17" data-doi="10.1029/96ja03294">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 17" href="http://scholar.google.com/scholar_lookup?&title=Characteristics%20of%20high-latitude%20TIDs%20from%20different%20causative%20mechanisms%20deduced%20by%20theoretical%20modeling&journal=J%20Geophys%20Res&doi=10.1029%2F96ja03294&volume=102&issue=A3&pages=4597-4612&publication_year=1997&author=Kirchengast%2CG"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR18">Kotake N, Otsuka Y, Ogawa T, Tsugawa T, Saito A (2007) Statistical study of medium-scale traveling ionospheric disturbances observed with the GPS networks in southern California. Earth Planet Sp 59(2):95–102. <a href="https://doi.org/10.1186/bf03352681" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1186/bf03352681">https://doi.org/10.1186/bf03352681</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="noopener" data-track-label="10.1186/bf03352681" data-track-item_id="10.1186/bf03352681" data-track-value="article reference" data-track-action="article reference" href="https://link.springer.com/doi/10.1186/bf03352681" aria-label="Article reference 18" data-doi="10.1186/bf03352681">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 18" href="http://scholar.google.com/scholar_lookup?&title=Statistical%20study%20of%20medium-scale%20traveling%20ionospheric%20disturbances%20observed%20with%20the%20GPS%20networks%20in%20southern%20California&journal=Earth%20Planet%20Sp&doi=10.1186%2Fbf03352681&volume=59&issue=2&pages=95-102&publication_year=2007&author=Kotake%2CN&author=Otsuka%2CY&author=Ogawa%2CT&author=Tsugawa%2CT&author=Saito%2CA"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR19">Kozlovsky A, Turunen T, Ulich T (2013) Rapid-run ionosonde observations of traveling ionospheric disturbances in the auroral ionosphere. J Geophys Res Space 118(8):5265–5276. <a href="https://doi.org/10.1002/jgra.50474" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1002/jgra.50474">https://doi.org/10.1002/jgra.50474</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/jgra.50474" data-track-item_id="10.1002/jgra.50474" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1002%2Fjgra.50474" aria-label="Article reference 19" data-doi="10.1002/jgra.50474">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 19" href="http://scholar.google.com/scholar_lookup?&title=Rapid-run%20ionosonde%20observations%20of%20traveling%20ionospheric%20disturbances%20in%20the%20auroral%20ionosphere&journal=J%20Geophys%20Res%20Space&doi=10.1002%2Fjgra.50474&volume=118&issue=8&pages=5265-5276&publication_year=2013&author=Kozlovsky%2CA&author=Turunen%2CT&author=Ulich%2CT"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR20">Macotela EL, Clilverd M, Renkwitz T, Chau J, Manninen J, Banyś D (2021) Spring-fall asymmetry in VLF amplitudes recorded in the North Atlantic region: The fall-effect. Geophys Res Lett 48:e2021GL094581. <a href="https://doi.org/10.1029/2021GL094581" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2021GL094581">https://doi.org/10.1029/2021GL094581</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2021GL094581" data-track-item_id="10.1029/2021GL094581" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2021GL094581" aria-label="Article reference 20" data-doi="10.1029/2021GL094581">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 20" href="http://scholar.google.com/scholar_lookup?&title=Spring-fall%20asymmetry%20in%20VLF%20amplitudes%20recorded%20in%20the%20North%20Atlantic%20region%3A%20The%20fall-effect&journal=Geophys%20Res%20Lett&doi=10.1029%2F2021GL094581&volume=48&publication_year=2021&author=Macotela%2CEL&author=Clilverd%2CM&author=Renkwitz%2CT&author=Chau%2CJ&author=Manninen%2CJ&author=Bany%C5%9B%2CD"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR21">Matthias V, Stober G, Kozlovsky A, Lester M, Belova E, Kero J (2021) Vertical structure of the Arctic spring transition in the middle atmosphere. J Geophys Res Atmos 126:e2020JD034353. <a href="https://doi.org/10.1029/2020JD034353" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2020JD034353">https://doi.org/10.1029/2020JD034353</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2020JD034353" data-track-item_id="10.1029/2020JD034353" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2020JD034353" aria-label="Article reference 21" data-doi="10.1029/2020JD034353">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 21" href="http://scholar.google.com/scholar_lookup?&title=Vertical%20structure%20of%20the%20Arctic%20spring%20transition%20in%20the%20middle%20atmosphere&journal=J%20Geophys%20Res%20Atmos&doi=10.1029%2F2020JD034353&volume=126&publication_year=2021&author=Matthias%2CV&author=Stober%2CG&author=Kozlovsky%2CA&author=Lester%2CM&author=Belova%2CE&author=Kero%2CJ"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR22">Moges ST, Sherstyukov RO, Kozlovsky A, Ulich T, Lester M (2024a) Statistics of traveling ionospheric disturbances at high latitudes using a rapid-run ionosonde. J Geophys Res Space 129:e0230JA31694. <a href="https://doi.org/10.1029/2023JA031694" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2023JA031694">https://doi.org/10.1029/2023JA031694</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2023JA031694" data-track-item_id="10.1029/2023JA031694" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2023JA031694" aria-label="Article reference 22" data-doi="10.1029/2023JA031694">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 22" href="http://scholar.google.com/scholar_lookup?&title=Statistics%20of%20traveling%20ionospheric%20disturbances%20at%20high%20latitudes%20using%20a%20rapid-run%20ionosonde&journal=J%20Geophys%20Res%20Space&doi=10.1029%2F2023JA031694&volume=129&publication_year=2024&author=Moges%2CST&author=Sherstyukov%2CRO&author=Kozlovsky%2CA&author=Ulich%2CT&author=Lester%2CM"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR23">Moges ST, Kozlovsky A, Sherstyukov RO, Ulich T (2024b) Solar activity dependence of traveling ionospheric disturbance amplitudes using a rapid-run ionosonde in high latitudes. J Geophys Res Space 129:e2024JA033013. <a href="https://doi.org/10.1029/2024JA033013" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2024JA033013">https://doi.org/10.1029/2024JA033013</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2024JA033013" data-track-item_id="10.1029/2024JA033013" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2024JA033013" aria-label="Article reference 23" data-doi="10.1029/2024JA033013">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 23" href="http://scholar.google.com/scholar_lookup?&title=Solar%20activity%20dependence%20of%20traveling%20ionospheric%20disturbance%20amplitudes%20using%20a%20rapid-run%20ionosonde%20in%20high%20latitudes&journal=J%20Geophys%20Res%20Space&doi=10.1029%2F2024JA033013&volume=129&publication_year=2024&author=Moges%2CST&author=Kozlovsky%2CA&author=Sherstyukov%2CRO&author=Ulich%2CT"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR24">Newell P, Meng C-I, Lyons K (1996) Suppression of discrete aurorae by sunlight. Nature 381:766–767. <a href="https://doi.org/10.1038/381766A0" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1038/381766A0">https://doi.org/10.1038/381766A0</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/381766A0" data-track-item_id="10.1038/381766A0" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1038%2F381766A0" aria-label="Article reference 24" data-doi="10.1038/381766A0">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="/articles/cas-redirect/1:CAS:528:DyaK28XjvVKgu70%3D" aria-label="CAS reference 24">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 24" href="http://scholar.google.com/scholar_lookup?&title=Suppression%20of%20discrete%20aurorae%20by%20sunlight&journal=Nature&doi=10.1038%2F381766A0&volume=381&pages=766-767&publication_year=1996&author=Newell%2CP&author=Meng%2CC-I&author=Lyons%2CK"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR25">Nygren T, Aikio A, Voiculescu M, Cai L (2015) Radar observations of simultaneous traveling ionospheric disturbances and atmospheric gravity waves. J Geophys Res Space 120(5):3949–3960. <a href="https://doi.org/10.1002/2014JA020794" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1002/2014JA020794">https://doi.org/10.1002/2014JA020794</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/2014JA020794" data-track-item_id="10.1002/2014JA020794" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1002%2F2014JA020794" aria-label="Article reference 25" data-doi="10.1002/2014JA020794">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 25" href="http://scholar.google.com/scholar_lookup?&title=Radar%20observations%20of%20simultaneous%20traveling%20ionospheric%20disturbances%20and%20atmospheric%20gravity%20waves&journal=J%20Geophys%20Res%20Space&doi=10.1002%2F2014JA020794&volume=120&issue=5&pages=3949-3960&publication_year=2015&author=Nygren%2CT&author=Aikio%2CA&author=Voiculescu%2CM&author=Cai%2CL"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR26">Oluwadare TS, Jakowski N, Valladares CE, Akala AO-O, Abe OE, Alizadeh MM, Schuh H (2022) Climatology of medium-scale traveling ionospheric disturbances (MSTIDs) observed with GPS networks in the North African region. Pure Appl Geophys 179:2501–2522. <a href="https://doi.org/10.1007/s00024-022-03028-6" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1007/s00024-022-03028-6">https://doi.org/10.1007/s00024-022-03028-6</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="noopener" data-track-label="10.1007/s00024-022-03028-6" data-track-item_id="10.1007/s00024-022-03028-6" data-track-value="article reference" data-track-action="article reference" href="https://link.springer.com/doi/10.1007/s00024-022-03028-6" aria-label="Article reference 26" data-doi="10.1007/s00024-022-03028-6">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 26" href="http://scholar.google.com/scholar_lookup?&title=Climatology%20of%20medium-scale%20traveling%20ionospheric%20disturbances%20%28MSTIDs%29%20observed%20with%20GPS%20networks%20in%20the%20North%20African%20region&journal=Pure%20Appl%20Geophys&doi=10.1007%2Fs00024-022-03028-6&volume=179&pages=2501-2522&publication_year=2022&author=Oluwadare%2CTS&author=Jakowski%2CN&author=Valladares%2CCE&author=Akala%2CAO-O&author=Abe%2COE&author=Alizadeh%2CMM&author=Schuh%2CH"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR27">Otsuka Y (2021) Medium-scale traveling ionospheric disturbances. In: Huang C, Lu G, Zhang Y, Paxton LJ (ed) Ionosphere dynamics and applications. <a href="https://doi.org/10.1002/9781119815617.ch18" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1002/9781119815617.ch18">https://doi.org/10.1002/9781119815617.ch18</a></p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR28">Otsuka Y, Shinbori A, Tsugawa T, Nishioka M (2021) Solar activity dependence of medium-scale traveling ionospheric disturbances using GPS receivers in Japan. Earth Planets Space 73:22. <a href="https://doi.org/10.1186/s40623-020-01353-5" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1186/s40623-020-01353-5">https://doi.org/10.1186/s40623-020-01353-5</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="noopener" data-track-label="10.1186/s40623-020-01353-5" data-track-item_id="10.1186/s40623-020-01353-5" data-track-value="article reference" data-track-action="article reference" href="https://link.springer.com/doi/10.1186/s40623-020-01353-5" aria-label="Article reference 28" data-doi="10.1186/s40623-020-01353-5">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 28" href="http://scholar.google.com/scholar_lookup?&title=Solar%20activity%20dependence%20of%20medium-scale%20traveling%20ionospheric%20disturbances%20using%20GPS%20receivers%20in%20Japan&journal=Earth%20Planets%20Space&doi=10.1186%2Fs40623-020-01353-5&volume=73&publication_year=2021&author=Otsuka%2CY&author=Shinbori%2CA&author=Tsugawa%2CT&author=Nishioka%2CM"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR29">Perkins F (1973) Spread F and ionospheric currents. J Geophys Res 78:218–226. <a href="https://doi.org/10.1029/JA078i001p00218" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/JA078i001p00218">https://doi.org/10.1029/JA078i001p00218</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/JA078i001p00218" data-track-item_id="10.1029/JA078i001p00218" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2FJA078i001p00218" aria-label="Article reference 29" data-doi="10.1029/JA078i001p00218">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 29" href="http://scholar.google.com/scholar_lookup?&title=Spread%20F%20and%20ionospheric%20currents&journal=J%20Geophys%20Res&doi=10.1029%2FJA078i001p00218&volume=78&pages=218-226&publication_year=1973&author=Perkins%2CF"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR30">Riggin D, Meyer C, Fritts D, Jarvis M, Murayama Y, Singer W, Vincent R, Murphy D (2003) MF radar observations of seasonal variability of semidiurnal motions in the mesosphere at high northern and southern latitudes. J Atmos Sol Terr Phys 65:483–493. <a href="https://doi.org/10.1016/S1364-6826(02)00340-1" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1016/S1364-6826(02)00340-1">https://doi.org/10.1016/S1364-6826(02)00340-1</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/S1364-6826(02)00340-1" data-track-item_id="10.1016/S1364-6826(02)00340-1" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1016%2FS1364-6826%2802%2900340-1" aria-label="Article reference 30" data-doi="10.1016/S1364-6826(02)00340-1">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 30" href="http://scholar.google.com/scholar_lookup?&title=MF%20radar%20observations%20of%20seasonal%20variability%20of%20semidiurnal%20motions%20in%20the%20mesosphere%20at%20high%20northern%20and%20southern%20latitudes&journal=J%20Atmos%20Sol%20Terr%20Phys&doi=10.1016%2FS1364-6826%2802%2900340-1&volume=65&pages=483-493&publication_year=2003&author=Riggin%2CD&author=Meyer%2CC&author=Fritts%2CD&author=Jarvis%2CM&author=Murayama%2CY&author=Singer%2CW&author=Vincent%2CR&author=Murphy%2CD"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR31">Reichert R, Kaifler B, Kaifler N, Rapp M, Pautet P-D, Taylor MJ, Kozlovsky A, Lester M, Kivi R (2019) Retrieval of intrinsic mesospheric gravity wave parameters using lidar and airglow temperature and meteor radar wind data. Atmos Meas Tech 12:5997–6015. <a href="https://doi.org/10.5194/amt-12-5997-2019" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.5194/amt-12-5997-2019">https://doi.org/10.5194/amt-12-5997-2019</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.5194/amt-12-5997-2019" data-track-item_id="10.5194/amt-12-5997-2019" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.5194%2Famt-12-5997-2019" aria-label="Article reference 31" data-doi="10.5194/amt-12-5997-2019">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 31" href="http://scholar.google.com/scholar_lookup?&title=Retrieval%20of%20intrinsic%20mesospheric%20gravity%20wave%20parameters%20using%20lidar%20and%20airglow%20temperature%20and%20meteor%20radar%20wind%20data&journal=Atmos%20Meas%20Tech&doi=10.5194%2Famt-12-5997-2019&volume=12&pages=5997-6015&publication_year=2019&author=Reichert%2CR&author=Kaifler%2CB&author=Kaifler%2CN&author=Rapp%2CM&author=Pautet%2CP-D&author=Taylor%2CMJ&author=Kozlovsky%2CA&author=Lester%2CM&author=Kivi%2CR"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR32">Sherstyukov R, Akchurin A, Sherstyukov O (2018) Collocated ionosonde and dense GPS/GLONASS network measurements of mid-latitude MSTIDs. Adv Space Res 61(7):1717–1725. <a href="https://doi.org/10.1016/j.asr.2017.11.026" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1016/j.asr.2017.11.026">https://doi.org/10.1016/j.asr.2017.11.026</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.asr.2017.11.026" data-track-item_id="10.1016/j.asr.2017.11.026" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1016%2Fj.asr.2017.11.026" aria-label="Article reference 32" data-doi="10.1016/j.asr.2017.11.026">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 32" href="http://scholar.google.com/scholar_lookup?&title=Collocated%20ionosonde%20and%20dense%20GPS%2FGLONASS%20network%20measurements%20of%20mid-latitude%20MSTIDs&journal=Adv%20Space%20Res&doi=10.1016%2Fj.asr.2017.11.026&volume=61&issue=7&pages=1717-1725&publication_year=2018&author=Sherstyukov%2CR&author=Akchurin%2CA&author=Sherstyukov%2CO"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR33">Sherstyukov R, Kozlovsky A, Ulich T, Moges S (2023) Deep learning for ionogram parameters scaling at polar region ionosphere. In: 2023 XXXVTH general assembly and scientific symposium of the international union of radio science (URSI GASS), pp 1–4. <a href="https://doi.org/10.23919/URSIGASS57860.2023.10265632" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.23919/URSIGASS57860.2023.10265632">https://doi.org/10.23919/URSIGASS57860.2023.10265632</a></p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR34">Sherstyukov R, Moges S, Kozlovsky A, Ulich T (2024) A deep learning approach for automatic ionogram parameters recognition with convolutional neural networks. Earth Space Sci 11:e2023EA003446. <a href="https://doi.org/10.1029/2023EA003446" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1029/2023EA003446">https://doi.org/10.1029/2023EA003446</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1029/2023EA003446" data-track-item_id="10.1029/2023EA003446" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.1029%2F2023EA003446" aria-label="Article reference 34" data-doi="10.1029/2023EA003446">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 34" href="http://scholar.google.com/scholar_lookup?&title=A%20deep%20learning%20approach%20for%20automatic%20ionogram%20parameters%20recognition%20with%20convolutional%20neural%20networks&journal=Earth%20Space%20Sci&doi=10.1029%2F2023EA003446&volume=11&publication_year=2024&author=Sherstyukov%2CR&author=Moges%2CS&author=Kozlovsky%2CA&author=Ulich%2CT"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR35">Stober G, Kozlovsky A, Liu A, Qiao Z, Tsutsumi M, Hall C, Nozawa S, Lester M, Belova E, Kero J, Espy PJ, Hibbons RE, Mitchell N (2021) Atmospheric tomography using the Nordic meteor radar cluster and Chilean observation network de meteor radars: network details and 3DVAR retrieval. Atmos Meas Tech 14:6509–6532. <a href="https://doi.org/10.5194/amt-14-6509-2021" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.5194/amt-14-6509-2021">https://doi.org/10.5194/amt-14-6509-2021</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.5194/amt-14-6509-2021" data-track-item_id="10.5194/amt-14-6509-2021" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.5194%2Famt-14-6509-2021" aria-label="Article reference 35" data-doi="10.5194/amt-14-6509-2021">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 35" href="http://scholar.google.com/scholar_lookup?&title=Atmospheric%20tomography%20using%20the%20Nordic%20meteor%20radar%20cluster%20and%20Chilean%20observation%20network%20de%20meteor%20radars%3A%20network%20details%20and%203DVAR%20retrieval&journal=Atmos%20Meas%20Tech&doi=10.5194%2Famt-14-6509-2021&volume=14&pages=6509-6532&publication_year=2021&author=Stober%2CG&author=Kozlovsky%2CA&author=Liu%2CA&author=Qiao%2CZ&author=Tsutsumi%2CM&author=Hall%2CC&author=Nozawa%2CS&author=Lester%2CM&author=Belova%2CE&author=Kero%2CJ&author=Espy%2CPJ&author=Hibbons%2CRE&author=Mitchell%2CN"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR36">Stober G, Liu A, Kozlovsky A, Qiao Z, Krochin W, Shi G, Kero J et al (2023) Identifying gravity waves launched by the Hunga Tonga-Hunga Ha‘apai volcanic eruption in mesosphere/lower thermosphere winds derived from CONDOR and the Nordic Meteor Radar Cluster. Ann Geophys 41:197–208. <a href="https://doi.org/10.5194/angeo-41-197-2023" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.5194/angeo-41-197-2023">https://doi.org/10.5194/angeo-41-197-2023</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.5194/angeo-41-197-2023" data-track-item_id="10.5194/angeo-41-197-2023" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.5194%2Fangeo-41-197-2023" aria-label="Article reference 36" data-doi="10.5194/angeo-41-197-2023">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 36" href="http://scholar.google.com/scholar_lookup?&title=Identifying%20gravity%20waves%20launched%20by%20the%20Hunga%20Tonga-Hunga%20Ha%E2%80%98apai%20volcanic%20eruption%20in%20mesosphere%2Flower%20thermosphere%20winds%20derived%20from%20CONDOR%20and%20the%20Nordic%20Meteor%20Radar%20Cluster&journal=Ann%20Geophys&doi=10.5194%2Fangeo-41-197-2023&volume=41&pages=197-208&publication_year=2023&author=Stober%2CG&author=Liu%2CA&author=Kozlovsky%2CA&author=Qiao%2CZ&author=Krochin%2CW&author=Shi%2CG&author=Kero%2CJ"> Google Scholar</a> </p></li><li class="c-article-references__item js-c-reading-companion-references-item"><p class="c-article-references__text" id="ref-CR37">Vlasov A, Kauristie K, Van de Kamp M, Luntama J-P, Pogoreltsev A (2011) A study of traveling ionospheric disturbances and atmospheric gravity waves using EISCAT Svalbard Radar IPY-data. Ann Geophys 29(11):2101–2116. <a href="https://doi.org/10.5194/angeo-29-2101-2011" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.5194/angeo-29-2101-2011">https://doi.org/10.5194/angeo-29-2101-2011</a></p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.5194/angeo-29-2101-2011" data-track-item_id="10.5194/angeo-29-2101-2011" data-track-value="article reference" data-track-action="article reference" href="https://doi.org/10.5194%2Fangeo-29-2101-2011" aria-label="Article reference 37" data-doi="10.5194/angeo-29-2101-2011">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 37" href="http://scholar.google.com/scholar_lookup?&title=A%20study%20of%20traveling%20ionospheric%20disturbances%20and%20atmospheric%20gravity%20waves%20using%20EISCAT%20Svalbard%20Radar%20IPY-data&journal=Ann%20Geophys&doi=10.5194%2Fangeo-29-2101-2011&volume=29&issue=11&pages=2101-2116&publication_year=2011&author=Vlasov%2CA&author=Kauristie%2CK&author=Kamp%2CM&author=Luntama%2CJ-P&author=Pogoreltsev%2CA"> Google Scholar</a> </p></li></ul><p class="c-article-references__download u-hide-print"><a data-track="click" data-track-action="download citation references" data-track-label="link" rel="nofollow" href="https://citation-needed.springer.com/v2/references/10.1007/s10712-025-09880-0?format=refman&flavour=references">Download references<svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-download-medium"></use></svg></a></p></div></div></div></section></div><section data-title="Acknowledgements"><div class="c-article-section" id="Ack1-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Ack1">Acknowledgements</h2><div class="c-article-section__content" id="Ack1-content"><p>This paper is an outcome of the Workshop “Physical Links Between Weather and Climate in Space and the Lower Atmosphere” held at the International Space Science Institute (ISSI) in Bern, Switzerland (22–26 January 2024). AK, GS, ML, JK, MT, SN acknowledge discussions within the ISSI in Bern, through ISSI International Team project 23-580 “Meteors and phenomena at the boundary between Earth's atmosphere and outer space.” RS was working in the Ionospheric Situational and Awareness (ISAw) project funded by Kvantum Institute at the University of Oulu. ML acknowledges support through STFC Grant ST/W00089X/1. GS is a member of the Oeschger Center for Climate Change Research (OCCR).</p></div></div></section><section data-title="Funding"><div class="c-article-section" id="Fun-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Fun">Funding</h2><div class="c-article-section__content" id="Fun-content"><p>Open Access funding provided by University of Oulu (including Oulu University Hospital).</p></div></div></section><section aria-labelledby="author-information" data-title="Author information"><div class="c-article-section" id="author-information-section"><h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="author-information">Author information</h2><div class="c-article-section__content" id="author-information-content"><h3 class="c-article__sub-heading" id="affiliations">Authors and Affiliations</h3><ol class="c-article-author-affiliation__list"><li id="Aff1"><p class="c-article-author-affiliation__address">Sodankylä Geophysical Observatory of the University of Oulu, 99600, Sodankylä, Finland</p><p class="c-article-author-affiliation__authors-list">Alexander Kozlovsky & Ruslan Sherstyukov</p></li><li id="Aff2"><p class="c-article-author-affiliation__address">Institute of Applied Physics and Oeschger Center for Climate Change Research, Microwave Physics, University of Bern, 3012, Bern, Switzerland</p><p class="c-article-author-affiliation__authors-list">Gunter Stober</p></li><li id="Aff3"><p class="c-article-author-affiliation__address">Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, UK</p><p class="c-article-author-affiliation__authors-list">Mark Lester</p></li><li id="Aff4"><p class="c-article-author-affiliation__address">Swedish Institute of Space Physics (IRF), 981 28, Kiruna, Sweden</p><p class="c-article-author-affiliation__authors-list">Evgenia Belova & Johan Kero</p></li><li id="Aff5"><p class="c-article-author-affiliation__address">National Institute of Polar Research, Tachikawa, Tokyo, 190-0014, Japan</p><p class="c-article-author-affiliation__authors-list">Masaki Tsutsumi</p></li><li id="Aff6"><p class="c-article-author-affiliation__address">The Graduate University for Advanced Studies (SOKENDAI), Tokyo, Japan</p><p class="c-article-author-affiliation__authors-list">Masaki Tsutsumi</p></li><li id="Aff7"><p class="c-article-author-affiliation__address">Tromsø Geophysical Observatory, UiT – The Arctic University of Norway, 9037, Tromsø, Norway</p><p class="c-article-author-affiliation__authors-list">Njål Gulbrandsen</p></li><li id="Aff8"><p class="c-article-author-affiliation__address">Division for Ionospheric and Magnetospheric Research Institute for Space-Earth Environment Research, Nagoya University, Nagoya, Aichi, 464-0805, Japan</p><p class="c-article-author-affiliation__authors-list">Satonori Nozawa</p></li></ol><div class="u-js-hide u-hide-print" data-test="author-info"><span class="c-article__sub-heading">Authors</span><ol class="c-article-authors-search u-list-reset"><li id="auth-Alexander-Kozlovsky-Aff1"><span class="c-article-authors-search__title u-h3 js-search-name">Alexander Kozlovsky</span><div class="c-article-authors-search__list"><div class="c-article-authors-search__item c-article-authors-search__list-item--left"><a href="/search?sortBy=newestFirst&dc.creator=Alexander%20Kozlovsky" class="c-article-button" data-track="click" data-track-action="author link - 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id="citeas">Cite this article</h3><p class="c-bibliographic-information__citation">Kozlovsky, A., Stober, G., Sherstyukov, R. <i>et al.</i> Atmospheric Gravity Waves and Medium Scale Traveling Ionospheric Disturbances at Auroral Latitudes. <i>Surv Geophys</i> (2025). https://doi.org/10.1007/s10712-025-09880-0</p><p class="c-bibliographic-information__download-citation u-hide-print"><a data-test="citation-link" data-track="click" data-track-action="download article citation" data-track-label="link" data-track-external="" rel="nofollow" href="https://citation-needed.springer.com/v2/references/10.1007/s10712-025-09880-0?format=refman&flavour=citation">Download citation<svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"><use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-download-medium"></use></svg></a></p><ul class="c-bibliographic-information__list" data-test="publication-history"><li class="c-bibliographic-information__list-item"><p>Received<span class="u-hide">: </span><span class="c-bibliographic-information__value"><time datetime="2024-09-26">26 September 2024</time></span></p></li><li class="c-bibliographic-information__list-item"><p>Accepted<span class="u-hide">: </span><span class="c-bibliographic-information__value"><time datetime="2025-02-11">11 February 2025</time></span></p></li><li class="c-bibliographic-information__list-item"><p>Published<span class="u-hide">: </span><span class="c-bibliographic-information__value"><time datetime="2025-03-06">06 March 2025</time></span></p></li><li class="c-bibliographic-information__list-item c-bibliographic-information__list-item--full-width"><p><abbr title="Digital Object Identifier">DOI</abbr><span class="u-hide">: </span><span class="c-bibliographic-information__value">https://doi.org/10.1007/s10712-025-09880-0</span></p></li></ul><div data-component="share-box"><div class="c-article-share-box u-display-none" 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