{"@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/1362825894296494080.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1029/2007gl030492"}},{"identifier":{"@type":"URI","@value":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2007GL030492"}},{"identifier":{"@type":"URI","@value":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2007GL030492"}}],"dc:title":[{"@value":"Observations of Pi2 pulsations by the Wallops HF radar in association with substorm expansion"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:p>We report the first sub‐auroral Pi2 pulsations observations by a SuperDARN type HF radar. The Wallops radar LOS measurements obtained at ionospheric altitudes, ∼56° magnetic latitude, 23 hour magnetic local time, are shown to be highly correlated with ground magnetic field perturbations obtained at Ottawa. The period of the Pi2 pulsations is 118 s and the m‐number is ∼2.3. The availability of both ionospheric LOS measurements and ground based magnetic field perturbations enable us to constrain the properties of the wave. A predominantly shear Alfven mode wave is able to explain both the amplitude and phase relations of our observations. Although the solar wind dynamic pressure is fairly stable the IMF Bz is highly variable thereby preventing an unambiguous identification of a solar wind trigger. Rather, magnetotail observations of a clear dipolarization and an intensification of the auroral westward electrojet producing a modest ground magnetic bay indicate that the wave is associated with the onset of a weak substorm.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1380848661784571140","@type":"Researcher","foaf:name":[{"@value":"J. W. Gjerloev"}],"jpcoar:affiliationName":[{"@value":"Applied Physics Laboratory Johns Hopkins University  Laurel Maryland USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494083","@type":"Researcher","foaf:name":[{"@value":"R. A. Greenwald"}],"jpcoar:affiliationName":[{"@value":"Applied Physics Laboratory Johns Hopkins University  Laurel Maryland USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494080","@type":"Researcher","foaf:name":[{"@value":"C. L. Waters"}],"jpcoar:affiliationName":[{"@value":"School of Mathematical and Physical Sciences University of Newcastle  New South Wales Australia"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494085","@type":"Researcher","foaf:name":[{"@value":"K. Takahashi"}],"jpcoar:affiliationName":[{"@value":"Applied Physics Laboratory Johns Hopkins University  Laurel Maryland USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494084","@type":"Researcher","foaf:name":[{"@value":"D. Sibeck"}],"jpcoar:affiliationName":[{"@value":"Laboratory for Extraterrestrial Physics NASA/Goddard Space Flight Center  Greenbelt Maryland USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494082","@type":"Researcher","foaf:name":[{"@value":"K. Oksavik"}],"jpcoar:affiliationName":[{"@value":"Applied Physics Laboratory Johns Hopkins University  Laurel Maryland USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494086","@type":"Researcher","foaf:name":[{"@value":"R. Barnes"}],"jpcoar:affiliationName":[{"@value":"Applied Physics Laboratory Johns Hopkins University  Laurel Maryland USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494081","@type":"Researcher","foaf:name":[{"@value":"J. Baker"}],"jpcoar:affiliationName":[{"@value":"Applied Physics Laboratory Johns Hopkins University  Laurel Maryland USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1382825894296494209","@type":"Researcher","foaf:name":[{"@value":"J. M. Ruohoniemi"}],"jpcoar:affiliationName":[{"@value":"Applied Physics Laboratory Johns Hopkins University  Laurel Maryland USA"}]}],"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":"2007-10","prism:volume":"34","prism:number":"20","prism:startingPage":"L20103"},"reviewed":"false","dc:rights":["http://onlinelibrary.wiley.com/termsAndConditions#vor"],"url":[{"@id":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2007GL030492"},{"@id":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2007GL030492"}],"createdAt":"2007-10-22","modifiedAt":"2023-10-31","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/2051151842044692096","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Review of the accomplishments of midlatitude Super Dual Auroral Radar Network (SuperDARN) HF radars"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1029/2007gl030492"},{"@type":"CROSSREF","@value":"10.1186/s40645-019-0270-5_references_DOI_Fl58WGN3dLlAQGw5Wzm6dOrXuHZ"}]}