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Ionospheric Flow Vortex Induced by the Sudden Decrease in the Solar Wind Dynamic Pressure
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  • Yaqi Jin,
  • Jøran Idar Moen,
  • Andres Spicher,
  • Jianjun Liu,
  • Lasse Boy Novock Clausen,
  • Wojciech Jacek Miloch
Yaqi Jin
University of Oslo

Corresponding Author:[email protected]

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Jøran Idar Moen
University Centre in Svalbard, Longyearbyen, Norway
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Andres Spicher
UiT The Arctic University of Norway
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Jianjun Liu
Polar Research Institute of China
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Lasse Boy Novock Clausen
University of Oslo
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Wojciech Jacek Miloch
University of Oslo
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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 side 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 flow vortex was first seen in the eastern field of view (FOV) of the Hankasalmi radar, and then propagated poleward and westward into the FOV of the ESR. During the passage of the flow vortex, a gradual decrease of electron density was observed by the field-aligned ESR 42 m antenna. When the equatorward directed ionospheric flow reached the ESR site, weak and visible increases in the electron density and electron temperature were observed. This impact was likely caused by soft electron precipitation associated with the clockwise flow vortex and upward field-aligned current. The azimuthal scan mode of the ESR 32 m radar at low elevation angle (30°) allowed us to measure key ionospheric parameters over a larger area (6° in latitude and 120° in azimuthal angle). The latitudinal scan of the electron temperature was used to derive the equatorward auroral boundary, which shows that the flow vortex was located in the subauroral region. We further demonstrated that it is possible to study the weak increase of electron density by using GPS total electron content (TEC) data. A minor TEC increase was observed near the center of the flow vortex.
13 May 2023Submitted to ESS Open Archive
25 May 2023Published in ESS Open Archive