Blar i forfatter "Clausen, Lasse"

Viser treff 1-7 av 7

    • Interferometric Study of Ionospheric Plasma Irregularities in Regions of Phase Scintillations and HF Backscatter 

      Spicher, Andres; LaBelle, James; Bonnell, John W.; Roglans, Roger; Moser, Chrystal; Fuselier, Stephen A.; Bounds, Scott; Clausen, Lasse; Di Mare, Francesca; Feltman, Connor A.; Jin, Yaqi; Kletzing, Craig; Miloch, Wojciech Jacek; Moen, Jøran Idar; Oksavik, Kjellmar; Sawyer, Rhyan; Takahashi, Toru; Yeoman, Tim K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-08)
      We investigate the nature of small-scale irregularities observed in the cusp by the Twin Rockets to Investigate Cusp Electrodynamics-2 (TRICE-2) in regions of enhanced phase scintillations and high-frequency coherent radar backscatter. We take advantage of the fact that the irregularities were detected by spatially separated probes, and present an interferometric analysis of both the observed electron ...

    • Ionospheric Flow Vortex Induced by the Sudden Decrease in the Solar Wind Dynamic Pressure 

      Jin, Yaqi; Moen, Jøran Idar; Spicher, Andres; Liu, Jianjun; Clausen, Lasse; Miloch, Wojciech Jacek (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-30)
      Abrupt changes in the solar wind dynamic pressure can greatly affect the Earth's magnetosphere-ionosphere system. We present an ionospheric flow vortex in the morning sector during the sudden decrease in the solar wind dynamic pressure. The flow vortex was clearly observed by both the Hankasalmi radar and the azimuthal scan mode of the European Incoherent Scatter (EISCAT) Svalbard Radar (ESR). The ...

    • Measuring small-scale plasma irregularities in the high-latitude E- and F-regions simultaneously 

      Ivarsen, Magnus Fagernes; St‐Maurice, Jean-Pierre; Hussey, Glenn C.; Spicher, Andres; Jin, Yaqi; Lozinsky, Adam; Goodwin, Lindsay Victoria; Galeschuk, Draven; Park, Jaeheung; Clausen, Lasse (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-18)
      The ionosphere, Earth’s space environment, exhibits widespread turbulent structuring, or plasma irregularities, visualized by the auroral displays seen in Earth’s polar regions. Such plasma irregularities have been studied for decades, but plasma turbulence remains an elusive phenomenon. We combine scale-dependent measurements from a ground-based radar with satellite observations to characterize ...

    • The role of particle precipitation on plasma structuring at different altitudes by in-situ measurements 

      Buschmann, Lisa Marie; Bonnell, John W.; Bounds, Scott; Clausen, Lasse; Kletzing, Craig; Marholm, Sigvald; Miloch, Wojciech Jacek; Roglans, Roger; Spicher, Andres (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-02)
      The plasma in the cusp ionosphere is subject to particle precipitation, which is important for the development of large-scale irregularities in the plasma density. These irregularities can be broken down into smaller scales which have been linked to strong scintillations in the Global Navigation Satellite System (GNSS) signals. We present power spectra for the plasma density irregularities in the ...

    • Statistical Distribution of Decameter Scale (50 m) Ionospheric Irregularities at High Latitudes 

      Jin, Yaqi; Clausen, Lasse; Spicher, Andres; Ivarsen, Magnus Fagernes; Zhang, Yongliang; Miloch, Wojciech Jacek; Moen, Jøran Idar (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-15)
      We present a study of decameter scale ionospheric irregularities using in-situ electron density data from the NorSat-1 satellite. During the current period of low solar activity, NorSat-1 frequently observes significant plasma irregularities from several 10 s km down to several decameter. These are often observed near the dayside cusp and dawnside auroral zone. The decameter-scale irregularities are ...

    • Suppression of ionospheric irregularity due to auroral particle impact 

      Takahashi, Toru; Spicher, Andres; Di Mare, Francesca; Rowland, Douglas E.; Pfaff, Robert F.; Collier, Michael R.; Clausen, Lasse; Moen, Jøran Idar (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-16)
      The VISIONS-2 35.039 sounding rocket was launched from Ny-Ålesund, Svalbard, on 7 December 2018 at 11:06 UT, and traveled overhead of the cusp aurora. The payload reached an apogee of 806.6 km and provided measurements of the electric field (E) and electron density (N<sub>e</sub> ) with a high sampling rate of 6,250 Hz. The high-sampling-data make it possible to estimate the horizontal structure ...

    • Turbulence and Intermittency in the Winter Cusp Ionosphere Studied With the ICI Sounding Rockets 

      Di Mare, Francesca; Spicher, Andres; Clausen, Lasse; Miloch, Wojciech Jacek; Moen, Jøran Idar (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-15)
      The characteristics of turbulent plasma in the winter cusp ionosphere is studied based on in-situ data from the Investigation of Cusp Irregularities (ICI) sounding rockets. The electron density fluctuations from ICI-2 and ICI-3 missions have been analyzed for the whole flight, using advanced timeseries analysis techniques. The analysis of the autocorrelation scale is indicative of the turbulence ...