{"@context":{"@vocab":"https://cir.nii.ac.jp/schema/1.0/","rdfs":"http://www.w3.org/2000/01/rdf-schema#","dc":"http://purl.org/dc/elements/1.1/","dcterms":"http://purl.org/dc/terms/","foaf":"http://xmlns.com/foaf/0.1/","prism":"http://prismstandard.org/namespaces/basic/2.0/","cinii":"http://ci.nii.ac.jp/ns/1.0/","datacite":"https://schema.datacite.org/meta/kernel-4/","ndl":"http://ndl.go.jp/dcndl/terms/","jpcoar":"https://github.com/JPCOAR/schema/blob/master/2.0/"},"@id":"https://cir.nii.ac.jp/crid/1360004229807899904.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1002/2017gl074678"}},{"identifier":{"@type":"URI","@value":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F2017GL074678"}},{"identifier":{"@type":"URI","@value":"https://onlinelibrary.wiley.com/doi/pdf/10.1002/2017GL074678"}},{"identifier":{"@type":"URI","@value":"https://onlinelibrary.wiley.com/doi/full-xml/10.1002/2017GL074678"}},{"identifier":{"@type":"URI","@value":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2017GL074678"}}],"resourceType":"学術雑誌論文(journal article)","dc:title":[{"@value":"The Solar Flux Dependence of Ionospheric 150 km Radar Echoes and Implications"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:title>Abstract</jats:title><jats:p>Radar echoes from the daytime equatorial ionospheric <jats:italic>F</jats:italic><jats:sub>1</jats:sub> region, popularly known as “150 km echoes,” have challenged ionospheric plasma physicists for several decades. Recent theoretical simulations showed that enhanced photoelectron fluxes can amplify the amplitude of plasma waves, generating spectra similar to those of the radar echoes, implying that larger solar fluxes should produce more frequent and stronger 150 km echoes. Inspired by this proposal, we studied the occurrence and intensity dependence of the echoes on the EUV flux observed by SOHO over several years. The occurrence and intensity of the echoes were found to have an inverse relationship with this EUV flux measurement. The multiyear trend is independent of the variability often observed over successive days with nearly identical EUV fluxes. These results imply that the relationship between the echoes and EUV flux is more complex. We propose that gravity waves modulate the amplitude of 150 km echoes through changes in the variations in plasma density and photoelectron fluxes associated with the gravity wave‐induced neutral density modulations.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1380004229807900035","@type":"Researcher","foaf:name":[{"@value":"A. K. Patra"}],"jpcoar:affiliationName":[{"@value":"National Atmospheric Research Laboratory  Gadanki India"}]},{"@id":"https://cir.nii.ac.jp/crid/1380004229807899904","@type":"Researcher","foaf:name":[{"@value":"P. Pavan Chaitanya"}],"jpcoar:affiliationName":[{"@value":"National Atmospheric Research Laboratory  Gadanki India"}]},{"@id":"https://cir.nii.ac.jp/crid/1380004229807900036","@type":"Researcher","foaf:name":[{"@value":"J.‐P. St.‐Maurice"}],"jpcoar:affiliationName":[{"@value":"Department of Physics and Engineering Physics University of Saskatchewan  Saskatoon Saskatchewan Canada"}]},{"@id":"https://cir.nii.ac.jp/crid/1380004229807900032","@type":"Researcher","foaf:name":[{"@value":"Y. Otsuka"}],"jpcoar:affiliationName":[{"@value":"Institute for Space‐Earth Environmental Research Nagoya University  Nagoya Japan"}]},{"@id":"https://cir.nii.ac.jp/crid/1380004229807900033","@type":"Researcher","foaf:name":[{"@value":"T. Yokoyama"}],"jpcoar:affiliationName":[{"@value":"National Institute of Information and Communication Technology  Tokyo Japan"}]},{"@id":"https://cir.nii.ac.jp/crid/1380004229807900034","@type":"Researcher","foaf:name":[{"@value":"M. Yamamoto"}],"jpcoar:affiliationName":[{"@value":"Research Institute for Sustainable Humanosphere Kyoto University  Uji Japan"}]}],"publication":{"publicationIdentifier":[{"@type":"PISSN","@value":"00948276"},{"@type":"EISSN","@value":"19448007"}],"prism:publicationName":[{"@value":"Geophysical Research Letters"}],"dc:publisher":[{"@value":"American Geophysical Union (AGU)"}],"prism:publicationDate":"2017-11-27","prism:volume":"44","prism:number":"22","prism:startingPage":"11264"},"reviewed":"false","dc:rights":["http://onlinelibrary.wiley.com/termsAndConditions#vor"],"url":[{"@id":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F2017GL074678"},{"@id":"https://onlinelibrary.wiley.com/doi/pdf/10.1002/2017GL074678"},{"@id":"https://onlinelibrary.wiley.com/doi/full-xml/10.1002/2017GL074678"},{"@id":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2017GL074678"}],"createdAt":"2017-11-13","modifiedAt":"2023-09-11","project":[{"@id":"https://cir.nii.ac.jp/crid/1040282256801950080","@type":"Project","projectIdentifier":[{"@type":"KAKEN","@value":"15H02135"},{"@type":"JGN","@value":"JP15H02135"},{"@type":"URI","@value":"https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15H02135/"}],"notation":[{"@language":"ja","@value":"新・衛星＝地上ビーコン観測と赤道大気レーダーによる低緯度電離圏の時空間変動の解明"},{"@language":"en","@value":"Study of spatio-temporal fluctuation of low 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