Heavy Ion Flows in the Upper Ionosphere of the Venusian North Pole
| Autor: | Stas Barabash, G. Stenberg Wieser, Hans Nilsson, T. L. Zhang, Yoshifumi Futaana, Maria Hamrin, Moa Persson, Andrei Fedorov |
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| Přispěvatelé: | Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2019 |
| Předmět: |
Venus ionosphere nightward flow
Physics North pole Spectrum analyzer 010504 meteorology & atmospheric sciences dusk-to-dawn flow pattern ion dynamics Plasma Space (mathematics) 01 natural sciences Ion Geophysics [SDU]Sciences of the Universe [physics] Physics::Plasma Physics Space and Planetary Science Physics::Space Physics Mass analyzer trans-terminator flow Heavy ion Ionosphere Atomic physics Venus North Pole 0105 earth and related environmental sciences |
| Zdroj: | Journal of Geophysical Research: Space Physics Journal of Geophysical Research: Space Physics, 2019, 124, pp.4597-4607. ⟨10.1029/2018JA026271⟩ |
| ISSN: | 2169-9402 2169-9380 |
| Popis: | International audience; We investigate the heavy ion density and velocity in the Venusian upper ionosphere near the North Pole, using the Ion Mass Analyzer, a part of the Analyzer of Space Plasmas and Energetic Atoms 4, together with the magnetic field instruments on Venus Express. The measurements were made during June-July 2014, covering the aerobraking campaign with lowered altitude measurements ( 130 km). The plasma scale heights are 15 km below 150-km altitude and 200 km at 150-400-km altitude. A clear trend of dusk-to-dawn heavy ion flow across the polar ionosphere was found, with speeds of 2-10 km/s. In addition, the flow has a significant downward radial velocity component. The flow pattern does not depend on the interplanetary magnetic field directions nor the ionospheric magnetization states. Instead, we suggest a thermal pressure gradient between the equatorial and polar terminator regions, induced by the decrease in density between the regions, as the dominant mechanism driving the ion flow. |
| Databáze: | OpenAIRE |
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