{"@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/1361418519917491968.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1029/2009ja014437"}},{"identifier":{"@type":"URI","@value":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2009JA014437"}},{"identifier":{"@type":"URI","@value":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009JA014437"}}],"dc:title":[{"@value":"Gadanki radar observations of <i>F</i> region field‐aligned irregularities during June solstice of solar minimum: First results and preliminary analysis"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:p>In this paper we present the first results of <jats:italic>F</jats:italic> region field‐aligned irregularities (FAI) made during the summer of low solar condition using the Gadanki mesosphere‐stratosphere‐troposphere radar. FAI echoes were observed on all 20 nights of radar observations and were mostly confined to the postmidnight hours. Echo morphology is found to be very different from the equinoctial postsunset features reported earlier from Gadanki. Echo SNRs are lower by 25 dB than their equinoctial postsunset counterparts but are quite comparable to those of the equinoctial decaying FAI during the postmidnight hours. The Doppler velocities, which lie in the range of ±100 m s<jats:sup>−1</jats:sup>, are predominantly upward‐northward during 0000–0300 LT and downward‐southward afterward, in contrast to those observed as predominantly downward‐southward associated with the decaying equinoctial postmidnight <jats:italic>F</jats:italic> region FAI. Spectral widths of the summer echoes, which are well below 50 m s<jats:sup>−1</jats:sup> and are very similar to those of the decaying equinoctial irregularities, represent the presence of weak plasma turbulence. Simultaneous observations made using a collocated ionosonde show no ionogram trace during 2200–0530 LT except for a few cases of weak spread <jats:italic>F</jats:italic> events. Concurrent ionosonde observations made from magnetic equatorial location Trivandrum also show very similar results. The observations are discussed in the light of current understanding on the postmidnight occurrence of <jats:italic>F</jats:italic> region irregularities in the summer of low solar condition.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1380298757412383254","@type":"Researcher","foaf:name":[{"@value":"A. K. Patra"}],"jpcoar:affiliationName":[{"@value":"National Atmospheric Research Laboratory  Gadanki India"}]},{"@id":"https://cir.nii.ac.jp/crid/1381418519917491970","@type":"Researcher","foaf:name":[{"@value":"D. V. Phanikumar"}],"jpcoar:affiliationName":[{"@value":"Korea Astronomy and Space Science Institute  Daejeon South Korea"}]},{"@id":"https://cir.nii.ac.jp/crid/1381418519917491969","@type":"Researcher","foaf:name":[{"@value":"T. K. Pant"}],"jpcoar:affiliationName":[{"@value":"Space Physics Laboratory Vikram Sarabhai Space Centre  Thiruvananthapuram India"}]}],"publication":{"publicationIdentifier":[{"@type":"PISSN","@value":"01480227"}],"prism:publicationName":[{"@value":"Journal of Geophysical Research: Space Physics"}],"dc:publisher":[{"@value":"American Geophysical Union (AGU)"}],"prism:publicationDate":"2009-12","prism:volume":"114","prism:number":"A12","prism:startingPage":"A12305"},"reviewed":"false","dc:rights":["http://onlinelibrary.wiley.com/termsAndConditions#vor"],"url":[{"@id":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2009JA014437"},{"@id":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009JA014437"}],"createdAt":"2009-12-03","modifiedAt":"2023-10-31","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/1050845763736019072","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@language":"en","@value":"Coordinated observations of postmidnight irregularities and thermospheric neutral winds and temperatures at low latitudes"}]},{"@id":"https://cir.nii.ac.jp/crid/1360017279829920128","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Evidence for the In‐Situ Generation of Plasma Depletion Structures Over the Transition Region of Geomagnetic Low‐Mid Latitude"}]},{"@id":"https://cir.nii.ac.jp/crid/1360298757412383488","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Challenges to Equatorial Plasma Bubble and Ionospheric Scintillation Short-Term Forecasting and Future Aspects in East and Southeast Asia"}]},{"@id":"https://cir.nii.ac.jp/crid/1360306905153809792","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Monitoring of Ionospheric Variability Using the Low lAtitude Long Range Ionospheric raDar (LARID): Capabilities, Advantages and Limitations"}]},{"@id":"https://cir.nii.ac.jp/crid/1360567179757409536","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Altitude development of postmidnight <i>F</i> region field‐aligned irregularities observed using Equatorial Atmosphere Radar in Indonesia"}]},{"@id":"https://cir.nii.ac.jp/crid/1360567183241974144","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"On postmidnight low-latitude ionospheric irregularities during solar minimum: 1. Equatorial Atmosphere Radar and GPS-TEC observations in Indonesia"}]},{"@id":"https://cir.nii.ac.jp/crid/1360576118797089024","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Anomalous Increase in the Occurrence of Post‐Midnight FAI Radar Echoes in September 2019 and Its Relation With the Austral Sudden Stratospheric Warming"}]},{"@id":"https://cir.nii.ac.jp/crid/2050870367065763072","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Review of the generation mechanisms of post-midnight irregularities in the equatorial and low-latitude ionosphere"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1029/2009ja014437"},{"@type":"CROSSREF","@value":"10.1029/2020ja028837_references_DOI_ZuzDWNZMSsSqXRQs6S7duKr6LjF"},{"@type":"CROSSREF","@value":"10.1007/s10712-020-09613-5_references_DOI_ZuzDWNZMSsSqXRQs6S7duKr6LjF"},{"@type":"CROSSREF","@value":"10.1029/2024sw004134_references_DOI_J4PNDHgAQxRBXcYl5HTCE2bZNjr"},{"@type":"CROSSREF","@value":"10.1002/2015gl067432_references_DOI_ZuzDWNZMSsSqXRQs6S7duKr6LjF"},{"@type":"CROSSREF","@value":"10.1029/2011ja016797_references_DOI_ZuzDWNZMSsSqXRQs6S7duKr6LjF"},{"@type":"CROSSREF","@value":"10.1029/2020ja028902_references_DOI_ZuzDWNZMSsSqXRQs6S7duKr6LjF"},{"@type":"CROSSREF","@value":"10.1002/2017ja024048_references_DOI_ZuzDWNZMSsSqXRQs6S7duKr6LjF"},{"@type":"CROSSREF","@value":"10.1186/s40645-018-0212-7_references_DOI_ZuzDWNZMSsSqXRQs6S7duKr6LjF"}]}