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Persson M, Aizawa S, André N, Barabash S, Saito Y, Harada Y, Heyner D, Orsini S, Fedorov A, Mazelle C, Futaana Y, Hadid LZ, Volwerk M, Collinson G, Sanchez-Cano B, Barthe A, Penou E, Yokota S, Génot V, Sauvaud JA, Delcourt D, Fraenz M, Modolo R, Milillo A, Auster HU, Richter I, Mieth JZD, Louarn P, Owen CJ, Horbury TS, Asamura K, Matsuda S, Nilsson H, Wieser M, Alberti T, Varsani A, Mangano V, Mura A, Lichtenegger H, Laky G, Jeszenszky H, Masunaga K, Signoles C, Rojo M, Murakami G. BepiColombo mission confirms stagnation region of Venus and reveals its large extent. Nat Commun 2022; 13:7743. [PMID: 36522338 PMCID: PMC9755131 DOI: 10.1038/s41467-022-35061-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/16/2022] [Indexed: 12/23/2022] Open
Abstract
The second Venus flyby of the BepiColombo mission offer a unique opportunity to make a complete tour of one of the few gas-dynamics dominated interaction regions between the supersonic solar wind and a Solar System object. The spacecraft pass through the full Venusian magnetosheath following the plasma streamlines, and cross the subsolar stagnation region during very stable solar wind conditions as observed upstream by the neighboring Solar Orbiter mission. These rare multipoint synergistic observations and stable conditions experimentally confirm what was previously predicted for the barely-explored stagnation region close to solar minimum. Here, we show that this region has a large extend, up to an altitude of 1900 km, and the estimated low energy transfer near the subsolar point confirm that the atmosphere of Venus, despite being non-magnetized and less conductive due to lower ultraviolet flux at solar minimum, is capable of withstanding the solar wind under low dynamic pressure.
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Affiliation(s)
- M. Persson
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - S. Aizawa
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - N. André
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - S. Barabash
- grid.425140.60000 0001 0706 1867Swedish Institute of Space Physics, Kiruna, Sweden
| | - Y. Saito
- grid.62167.340000 0001 2220 7916Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kyoto, Japan
| | - Y. Harada
- grid.258799.80000 0004 0372 2033Department of Geophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - D. Heyner
- grid.6738.a0000 0001 1090 0254Institute for Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Braunschweig, Germany
| | - S. Orsini
- grid.4293.c0000 0004 1792 8585Institute of Space Astrophysics and Planetology, Istituto Nazionale di Astrofisica, Rome, Italy
| | - A. Fedorov
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - C. Mazelle
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - Y. Futaana
- grid.425140.60000 0001 0706 1867Swedish Institute of Space Physics, Kiruna, Sweden
| | - L. Z. Hadid
- grid.508893.fLaboratoire de Physique des Plasmas (LPP), Centre National de la Recherche Scientifique, Observatoire de Paris, Sorbonne Université, Université Paris Saclay, École Polytechnique, Institut Polytechnique de Paris, Paris, France
| | - M. Volwerk
- grid.4299.60000 0001 2169 3852Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - G. Collinson
- grid.133275.10000 0004 0637 6666National Aeronautic and Space Administration, Goddard Space Flight Center, Greenbelt, MD USA
| | - B. Sanchez-Cano
- grid.9918.90000 0004 1936 8411School of Physics and Astronomy, University of Leicester, Leicester, UK
| | - A. Barthe
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - E. Penou
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - S. Yokota
- grid.136593.b0000 0004 0373 3971Department of Earth and Space Science, Graduate School of Science, Osaka University, Osaka, Japan
| | - V. Génot
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - J. A. Sauvaud
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - D. Delcourt
- grid.508893.fLaboratoire de Physique des Plasmas (LPP), Centre National de la Recherche Scientifique, Observatoire de Paris, Sorbonne Université, Université Paris Saclay, École Polytechnique, Institut Polytechnique de Paris, Paris, France
| | - M. Fraenz
- grid.435826.e0000 0001 2284 9011Max-Planck-Institute for Solar System Research, Göttingen, Germany
| | - R. Modolo
- Laboratoire Atmosphères, Milieux, Observations Spatiales, Institut Pierre Simon Laplace, Université Versailles Saint Quentin en Yvelines, Université Paris-Saclay, Université Pierre Marie Curie, Centre National de la Recherche Scientifique, Guyancourt, France
| | - A. Milillo
- grid.4293.c0000 0004 1792 8585Institute of Space Astrophysics and Planetology, Istituto Nazionale di Astrofisica, Rome, Italy
| | - H.-U. Auster
- grid.6738.a0000 0001 1090 0254Institute for Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Braunschweig, Germany
| | - I. Richter
- grid.6738.a0000 0001 1090 0254Institute for Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Braunschweig, Germany
| | - J. Z. D. Mieth
- grid.6738.a0000 0001 1090 0254Institute for Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Braunschweig, Germany
| | - P. Louarn
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - C. J. Owen
- grid.83440.3b0000000121901201Mullard Space Science Laboratory, University College London, Holmbury St. Mary, UK
| | - T. S. Horbury
- grid.7445.20000 0001 2113 8111Imperial College London, South Kensington Campus, London, UK
| | - K. Asamura
- grid.62167.340000 0001 2220 7916Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kyoto, Japan
| | - S. Matsuda
- grid.9707.90000 0001 2308 3329Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Japan
| | - H. Nilsson
- grid.425140.60000 0001 0706 1867Swedish Institute of Space Physics, Kiruna, Sweden
| | - M. Wieser
- grid.425140.60000 0001 0706 1867Swedish Institute of Space Physics, Kiruna, Sweden
| | - T. Alberti
- grid.4293.c0000 0004 1792 8585Institute of Space Astrophysics and Planetology, Istituto Nazionale di Astrofisica, Rome, Italy
| | - A. Varsani
- grid.4299.60000 0001 2169 3852Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - V. Mangano
- grid.4293.c0000 0004 1792 8585Institute of Space Astrophysics and Planetology, Istituto Nazionale di Astrofisica, Rome, Italy
| | - A. Mura
- grid.4293.c0000 0004 1792 8585Institute of Space Astrophysics and Planetology, Istituto Nazionale di Astrofisica, Rome, Italy
| | - H. Lichtenegger
- grid.4299.60000 0001 2169 3852Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - G. Laky
- grid.4299.60000 0001 2169 3852Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - H. Jeszenszky
- grid.4299.60000 0001 2169 3852Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - K. Masunaga
- grid.62167.340000 0001 2220 7916Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kyoto, Japan
| | - C. Signoles
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - M. Rojo
- grid.15781.3a0000 0001 0723 035XInstitut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Centre National d’Etudes Spatiales, Université Paul Sabatier—Toulouse III, Toulouse, France
| | - G. Murakami
- grid.62167.340000 0001 2220 7916Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kyoto, Japan
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Andrés N, Sahraoui F, Galtier S, Hadid LZ, Ferrand R, Huang SY. Energy Cascade Rate Measured in a Collisionless Space Plasma with MMS Data and Compressible Hall Magnetohydrodynamic Turbulence Theory. Phys Rev Lett 2019; 123:245101. [PMID: 31922873 DOI: 10.1103/physrevlett.123.245101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/12/2019] [Indexed: 06/10/2023]
Abstract
The first complete estimation of the compressible energy cascade rate |ϵ_{C}| at magnetohydrodynamic (MHD) and subion scales is obtained in Earth's magnetosheath using Magnetospheric MultiScale spacecraft data and an exact law derived recently for compressible Hall MHD turbulence. A multispacecraft technique is used to compute the velocity and magnetic gradients, and then all the correlation functions involved in the exact relation. It is shown that when the density fluctuations are relatively small, |ϵ_{C}| identifies well with its incompressible analog |ϵ_{I}| at MHD scales but becomes much larger than |ϵ_{I}| at subion scales. For larger density fluctuations, |ϵ_{C}| is larger than |ϵ_{I}| at every scale with a value significantly higher than for smaller density fluctuations. Our study reveals also that for both small and large density fluctuations, the nonflux terms remain always negligible with respect to the flux terms and that the major contribution to |ϵ_{C}| at subion scales comes from the compressible Hall flux.
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Affiliation(s)
- N Andrés
- Laboratoire de Physique des Plasmas, École Polytechnique, CNRS, Sorbonne University, Observatoire de Paris, Univ. Paris-Sud, F-91128 Palaiseau Cedex, France
- Instituto de Astronomía y Física del Espacio, CONICET-UBA, Ciudad Universitaria, 1428, Buenos Aires, Argentina
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, UBA, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - F Sahraoui
- Laboratoire de Physique des Plasmas, École Polytechnique, CNRS, Sorbonne University, Observatoire de Paris, Univ. Paris-Sud, F-91128 Palaiseau Cedex, France
| | - S Galtier
- Laboratoire de Physique des Plasmas, École Polytechnique, CNRS, Sorbonne University, Observatoire de Paris, Univ. Paris-Sud, F-91128 Palaiseau Cedex, France
- Institut Universitaire de France (IUF), 2201 France
| | - L Z Hadid
- European Space Agency, ESTEC, 75231 Noordwijk, Netherlands
| | - R Ferrand
- Laboratoire de Physique des Plasmas, École Polytechnique, CNRS, Sorbonne University, Observatoire de Paris, Univ. Paris-Sud, F-91128 Palaiseau Cedex, France
| | - S Y Huang
- School of Electronic and Information, Wuhan University, 430072 Wuhan, China
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Waite JH, Perryman RS, Perry ME, Miller KE, Bell J, Cravens TE, Glein CR, Grimes J, Hedman M, Cuzzi J, Brockwell T, Teolis B, Moore L, Mitchell DG, Persoon A, Kurth WS, Wahlund JE, Morooka M, Hadid LZ, Chocron S, Walker J, Nagy A, Yelle R, Ledvina S, Johnson R, Tseng W, Tucker OJ, Ip WH. Chemical interactions between Saturn’s atmosphere and its rings. Science 2018; 362:362/6410/eaat2382. [DOI: 10.1126/science.aat2382] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 09/10/2018] [Indexed: 11/03/2022]
Abstract
The Pioneer and Voyager spacecraft made close-up measurements of Saturn’s ionosphere and upper atmosphere in the 1970s and 1980s that suggested a chemical interaction between the rings and atmosphere. Exploring this interaction provides information on ring composition and the influence on Saturn’s atmosphere from infalling material. The Cassini Ion Neutral Mass Spectrometer sampled in situ the region between the D ring and Saturn during the spacecraft’s Grand Finale phase. We used these measurements to characterize the atmospheric structure and material influx from the rings. The atmospheric He/H2 ratio is 10 to 16%. Volatile compounds from the rings (methane; carbon monoxide and/or molecular nitrogen), as well as larger organic-bearing grains, are flowing inward at a rate of 4800 to 45,000 kilograms per second.
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Hadid LZ, Sahraoui F, Galtier S, Huang SY. Compressible Magnetohydrodynamic Turbulence in the Earth's Magnetosheath: Estimation of the Energy Cascade Rate Using in situ Spacecraft Data. Phys Rev Lett 2018; 120:055102. [PMID: 29481187 DOI: 10.1103/physrevlett.120.055102] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 10/18/2017] [Indexed: 06/08/2023]
Abstract
The first estimation of the energy cascade rate |ε_{C}| of magnetosheath turbulence is obtained using the Cluster and THEMIS spacecraft data and an exact law of compressible isothermal magnetohydrodynamics turbulence. The mean value of |ε_{C}| is found to be close to 10^{-13} J m^{-3} s^{-1}, at least 2 orders of magnitude larger than its value in the solar wind (∼10^{-16} J m^{-3} s^{-1} in the fast wind). Two types of turbulence are evidenced and shown to be dominated either by incompressible Alfvénic or compressible magnetosoniclike fluctuations. Density fluctuations are shown to amplify the cascade rate and its spatial anisotropy in comparison with incompressible Alfvénic turbulence. Furthermore, for compressible magnetosonic fluctuations, large cascade rates are found to lie mostly near the linear kinetic instability of the mirror mode. New empirical power-laws relating |ε_{C}| to the turbulent Mach number and to the internal energy are evidenced. These new findings have potential applications in distant astrophysical plasmas that are not accessible to in situ measurements.
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Affiliation(s)
- L Z Hadid
- Swedish Institute of Space Physics, SE 751 21, Uppsala, Sweden and LPP, CNRS, Ecole Polytechnique, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, Sorbonne Université, PSL Research University, 91128 Palaiseau, France
| | - F Sahraoui
- LPP, CNRS, Ecole Polytechnique, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, Sorbonne Université, PSL Research University, 91128 Palaiseau, France
| | - S Galtier
- LPP, CNRS, Ecole Polytechnique, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, Sorbonne Université, PSL Research University, 91128 Palaiseau, France
| | - S Y Huang
- School of Electronic Information, Wuhan University, Wuhan 430072, China
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Wahlund JE, Morooka MW, Hadid LZ, Persoon AM, Farrell WM, Gurnett DA, Hospodarsky G, Kurth WS, Ye SY, Andrews DJ, Edberg NJT, Eriksson AI, Vigren E. In situ measurements of Saturn's ionosphere show that it is dynamic and interacts with the rings. Science 2017; 359:66-68. [PMID: 29229651 DOI: 10.1126/science.aao4134] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/27/2017] [Indexed: 11/02/2022]
Abstract
The ionized upper layer of Saturn's atmosphere, its ionosphere, provides a closure of currents mediated by the magnetic field to other electrically charged regions (for example, rings) and hosts ion-molecule chemistry. In 2017, the Cassini spacecraft passed inside the planet's rings, allowing in situ measurements of the ionosphere. The Radio and Plasma Wave Science instrument detected a cold, dense, and dynamic ionosphere at Saturn that interacts with the rings. Plasma densities reached up to 1000 cubic centimeters, and electron temperatures were below 1160 kelvin near closest approach. The density varied between orbits by up to two orders of magnitude. Saturn's A- and B-rings cast a shadow on the planet that reduced ionization in the upper atmosphere, causing a north-south asymmetry.
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Affiliation(s)
- J-E Wahlund
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden.
| | - M W Morooka
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
| | - L Z Hadid
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
| | - A M Persoon
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA
| | - W M Farrell
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - D A Gurnett
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA
| | - G Hospodarsky
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA
| | - W S Kurth
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA
| | - S-Y Ye
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA
| | - D J Andrews
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
| | - N J T Edberg
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
| | - A I Eriksson
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
| | - E Vigren
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
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