Blar i forfatter "Gustavsson, Bjorn Johan"

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    • The altitude of green OI 557.7 nm and blue N2+ 427.8 nm aurora 

      Whiter, Daniel K.; Partamies, Noora; Gustavsson, Bjorn Johan; Kauristie, Kirsti (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-06)
      We have performed a large statistical study of the peak emission altitude of green O(1D2–1S0) (557.7 nm) and blue 1 N (427.8 nm) aurora using observations from a network of all-sky cameras stationed across northern Finland and Sweden recorded during seven winter seasons from 2000 to 2007. Both emissions were found to typically peak at about 114 km. The distribution of blue peak altitudes is more ...

    • Manx Arrays: Perfect Non-Redundant Interferometric Geometries 

      McKay, Derek; Grydeland, Tom; Gustavsson, Bjorn Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-09)
      Interferometry applications (e.g., radio astronomy) often wish to optimize the placement of the interferometric elements. One such optimal criterion is a uniform distribution of non-redundant element spacings (in both distance and position angle). While large systems, with many elements, can rely on saturating the sample space, and disregard “wasted” sampling, small arrays with only a few elements ...

    • Multi-instrument observations of the Pajala fireball: origin, characteristics, and atmospheric implications 

      Vierinen, Juha; Aslaksen, Torstein; Chau, Jorge L.; Gritsevich, Maria; Gustavsson, Bjorn Johan; Kastinen, Daniel; Kero, Johan; Kozlovsky, Alexandre; Kværna, Tormod; Näsholm, Sven Peter; Ulich, Thomas; Vegum, Ketil; Midtskogen, Steinar; Lester, Mark (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-07)
      Meteor observations provide information about Solar System constituents and their influx onto Earth, their interaction processes in the atmosphere, as well as the neutral dynamics of the upper atmosphere. This study presents optical, radar, and infrasound measurements of a daytime fireball that occurred on 4 December 2020 at 13:30 UTC over Northeast Sweden. The fireball was recorded with two video ...

    • A technique for volumetric incoherent scatter radar analysis 

      Stamm, Johann Immanuel; Vierinen, Juha; Gustavsson, Bjorn Johan; Spicher, Andres (Journal article; Tidsskriftartikkel, 2023-01-19)
      Volumetric measurements of the ionosphere are important for investigating spatial variations of ionospheric features, like auroral arcs and energy deposition in the ionosphere. In addition, such measurements make it possible to distinguish between variations in space and time. While spatial variations in scalar quantities such as electron density or temperature have been investigated with incoherent ...