{"@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/1363670319016540160.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1029/2004ja010464"}},{"identifier":{"@type":"URI","@value":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2004JA010464"}},{"identifier":{"@type":"URI","@value":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004JA010464"}}],"dc:title":[{"@value":"Substorm injection modeling with nondipolar, time‐dependent background field"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:p>We model energetic particle injections during substorms by investigating the particle interaction with an earthward propagating electromagnetic pulse of spatially localized transient electric (<jats:bold>E</jats:bold>) and magnetic (<jats:bold>B</jats:bold>) fields, superposed over a background <jats:bold>B</jats:bold> field. The current work extends our previous model by considering the background field to be nondipolar (stretched) before the arrival of the pulse (i.e., during the substorm growth phase), changing in a time‐dependent manner into a dipole field in the wake of the pulse. The particle motion still conserves the first adiabatic invariant, even in the stretched <jats:bold>B</jats:bold> field, and both protons and electrons are convected earthward by the <jats:bold>E</jats:bold> × <jats:bold>B</jats:bold> drift to regions of higher field, undergoing betatron acceleration. As in the previous model, we find fully analytical solutions for the gyrocenter motion of the 90° pitch angle particles, and we use them to compute the injected particle flux. We discuss how the model can explain several injection features such as the low/high energy cutoffs, and finally we apply the solutions to a simulation of an actual injection event, obtaining good agreement with observations. The current results with the more realistic background field show significant increase in particle flux for “substorm energies” (tens to hundreds of keVs) compared with the case of a dipole background, leading to the conclusion that the particles have to arrive from closer to Earth than before in order to explain the observed injected flux levels. The new model provides a better fit to observations than the previous one, since it requires lower transient <jats:bold>E</jats:bold> fields (more realistic of a typical substorm), and thus better explains the ubiquity of particle injections associated with substorms.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1383670319016540160","@type":"Researcher","foaf:name":[{"@value":"Sorin Zaharia"}],"jpcoar:affiliationName":[{"@value":"Los Alamos National Laboratory  Los Alamos New Mexico USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1380579817113467137","@type":"Researcher","foaf:name":[{"@value":"J. Birn"}],"jpcoar:affiliationName":[{"@value":"Los Alamos National Laboratory  Los Alamos New Mexico USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1380579817113467138","@type":"Researcher","foaf:name":[{"@value":"R. H. W. Friedel"}],"jpcoar:affiliationName":[{"@value":"Los Alamos National Laboratory  Los Alamos New Mexico USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1380579817113467136","@type":"Researcher","foaf:name":[{"@value":"G. D. Reeves"}],"jpcoar:affiliationName":[{"@value":"Los Alamos National Laboratory  Los Alamos New Mexico USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1380579817113467140","@type":"Researcher","foaf:name":[{"@value":"M. F. Thomsen"}],"jpcoar:affiliationName":[{"@value":"Los Alamos National Laboratory  Los Alamos New Mexico USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1380579817113467139","@type":"Researcher","foaf:name":[{"@value":"C. Z. Cheng"}],"jpcoar:affiliationName":[{"@value":"Princeton Plasma Physics Laboratory Princeton University  Princeton New Jersey USA"}]}],"publication":{"publicationIdentifier":[{"@type":"PISSN","@value":"01480227"}],"prism:publicationName":[{"@value":"Journal of Geophysical Research: Space Physics"}],"dc:publisher":[{"@value":"American Geophysical Union (AGU)"}],"prism:publicationDate":"2004-10","prism:volume":"109","prism:number":"A10","prism:startingPage":"A10211"},"reviewed":"false","dc:rights":["http://onlinelibrary.wiley.com/termsAndConditions#vor"],"url":[{"@id":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2004JA010464"},{"@id":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004JA010464"}],"createdAt":"2004-10-23","modifiedAt":"2023-10-31","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/1360283689327292160","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Van Allen Probes observations of magnetic field dipolarization and its associated O<sup>+</sup> flux variations in the inner magnetosphere at <i>L</i> < 6.6"}]},{"@id":"https://cir.nii.ac.jp/crid/2050870367066593280","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"ERG observations of drift echoes during a unique period of the satellite mission"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1029/2004ja010464"},{"@type":"CROSSREF","@value":"10.1002/2016ja022549_references_DOI_VP6qBbVXVwBxI86u8FRCsCy7xr3"},{"@type":"CROSSREF","@value":"10.1186/s40623-019-0999-5_references_DOI_VP6qBbVXVwBxI86u8FRCsCy7xr3"}]}