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Yoshioka K, Murakami G, Yamazaki A, Tsuchiya F, Kimura T, Kagitani M, Sakanoi T, Uemizu K, Kasaba Y, Yoshikawa I, Fujimoto M. Evidence for global electron transportation into the jovian inner magnetosphere. Science 2014; 345:1581-4. [PMID: 25258073 DOI: 10.1126/science.1256259] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Jupiter's magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves.
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Affiliation(s)
- K Yoshioka
- Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan.
| | - G Murakami
- Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan
| | - A Yamazaki
- Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan
| | - F Tsuchiya
- Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Japan
| | - T Kimura
- Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan
| | - M Kagitani
- Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Japan
| | - T Sakanoi
- Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Japan
| | - K Uemizu
- Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan. National Astronomical Observatory of Japan, Mitaka, Japan
| | - Y Kasaba
- Department of Geophysics, Tohoku University, Sendai, Japan
| | - I Yoshikawa
- Department of Earth and Planetary Science, University of Tokyo, Tokyo, Japan
| | - M Fujimoto
- Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan. Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
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Dols V, Delamere PA, Bagenal F, Kurth WS, Paterson WR. Asymmetry of Io's outer atmosphere: Constraints from five Galileo flybys. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012je004076] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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3
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Bagenal F, Delamere PA. Flow of mass and energy in the magnetospheres of Jupiter and Saturn. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010ja016294] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fran Bagenal
- Laboratory for Atmospheric and Space Physics; University of Colorado at Boulder; Boulder Colorado USA
| | - Peter A. Delamere
- Laboratory for Atmospheric and Space Physics; University of Colorado at Boulder; Boulder Colorado USA
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Jones ST, Su YJ. Role of dispersive Alfvén waves in generating parallel electric fields along the Io-Jupiter fluxtube. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008ja013512] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- S. T. Jones
- Department of Physics; University of Texas at Arlington; Arlington Texas USA
| | - Y.-J. Su
- Department of Physics; University of Texas at Arlington; Arlington Texas USA
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Menietti JD, Santolik O, Rymer AM, Hospodarsky GB, Persoon AM, Gurnett DA, Coates AJ, Young DT. Analysis of plasma waves observed within local plasma injections seen in Saturn's magnetosphere. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007ja012856] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- J. D. Menietti
- Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
| | - O. Santolik
- Institute of Atmospheric Physics; ASCR, and Charles University; Prague Czech Republic
| | - A. M. Rymer
- Johns Hopkins University, Applied Physics Laboratory; Laurel Maryland USA
| | - G. B. Hospodarsky
- Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
| | - A. M. Persoon
- Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
| | - D. A. Gurnett
- Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
| | - A. J. Coates
- University College London, Mullard Space Science Laboratory; Dorking UK
| | - D. T. Young
- Southwest Research Institute; San Antonio Texas USA
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6
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Burch JL, Goldstein J, Lewis WS, Young DT, Coates AJ, Dougherty MK, André N. Tethys and Dione as sources of outward-flowing plasma in Saturn’s magnetosphere. Nature 2007; 447:833-5. [PMID: 17568741 DOI: 10.1038/nature05906] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Accepted: 05/04/2007] [Indexed: 11/09/2022]
Abstract
Rotating at over twice the angular speed of Earth, Saturn imposes a rapid spin on its magnetosphere. As a result, cold, dense plasma is believed to be flung outward from the inner magnetosphere by centrifugal force and replaced by hotter, more tenuous plasma from the outer magnetosphere. The centrifugal interchange of plasmas in rotating magnetospheres was predicted many years ago and was conclusively demonstrated by observations in Jupiter's magnetosphere, which--like that of Saturn (but unlike that of Earth)--is rotationally dominated. Recent observations in Saturn's magnetosphere have revealed narrow injections of hot, tenuous plasma believed to be the inward-moving portion of the centrifugal interchange cycle. Here we report observations of the distribution of the angle between the electron velocity vector and the magnetic field vector ('pitch angle') obtained in the cold, dense plasma adjacent to these inward injection regions. The observed pitch-angle distributions are indicative of outward plasma flow and consistent with centrifugal interchange in Saturn's magnetosphere. Further, we conclude that the observed double-peaked ('butterfly') pitch-angle distributions result from the transport of plasma from regions near the orbits of Dione and Tethys, supporting the idea of distinct plasma tori associated with these moons.
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Affiliation(s)
- J L Burch
- Southwest Research Institute, PO Drawer 28510, San Antonio, Texas 78228-0510, USA
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Rymer AM, Mauk BH, Hill TW, Paranicas C, André N, Sittler EC, Mitchell DG, Smith HT, Johnson RE, Coates AJ, Young DT, Bolton SJ, Thomsen MF, Dougherty MK. Electron sources in Saturn's magnetosphere. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006ja012017] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- A. M. Rymer
- Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
| | - B. H. Mauk
- Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
| | - T. W. Hill
- Department of Physics and Astronomy; Rice University; Houston Texas USA
| | - C. Paranicas
- Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
| | - N. André
- Research and Scientific Support Department; European Space Agency; Noordwijk Netherlands
| | - E. C. Sittler
- NASA Goddard Space Flight Center; Greenbelt Maryland USA
| | - D. G. Mitchell
- Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
| | - H. T. Smith
- University of Virginia; Charlottesville Virginia USA
| | - R. E. Johnson
- University of Virginia; Charlottesville Virginia USA
| | - A. J. Coates
- Mullard Space Science Laboratory; University College London; London UK
| | - D. T. Young
- Southwest Research Institute; San Antonio Texas USA
| | - S. J. Bolton
- Southwest Research Institute; San Antonio Texas USA
| | - M. F. Thomsen
- Space and Atmospheric Science Group; Los Alamos National Laboratory; Los Alamos New Mexico USA
| | - M. K. Dougherty
- Department of Space and Atmospheric Physics; Imperial College London; London UK
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8
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Mauk BH. Energetic ion characteristics and neutral gas interactions in Jupiter's magnetosphere. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003ja010270] [Citation(s) in RCA: 172] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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9
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André N. Low-frequency waves and instabilities in stratified, gyrotropic, multicomponent plasmas: Theory and application to plasma transport in the Io torus. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004ja010599] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Su YJ, Ergun RE, Bagenal F, Delamere PA. Io-related Jovian auroral arcs: Modeling parallel electric fields. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002ja009247] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yi-Jiun Su
- Laboratory for Atmospheric and Space Physics; University of Colorado; Boulder Colorado USA
| | - Robert E. Ergun
- Laboratory for Atmospheric and Space Physics; University of Colorado; Boulder Colorado USA
| | - Fran Bagenal
- Laboratory for Atmospheric and Space Physics; University of Colorado; Boulder Colorado USA
| | - Peter A. Delamere
- Laboratory for Atmospheric and Space Physics; University of Colorado; Boulder Colorado USA
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Frank LA, Paterson WR. Galileo observations of electron beams and thermal ions in Jupiter's magnetosphere and their relationship to the auroras. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001ja009150] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- L. A. Frank
- Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
| | - W. R. Paterson
- Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
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Oliversen RJ, Scherb F, Smyth WH, Freed ME, Woodward RC, Marconi ML, Retherford KD, Lupie OL, Morgenthaler JP. Sunlit Io atmospheric [O I] 6300 Å emission and the plasma torus. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja002507] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Frank LA, Paterson WR. Survey of thermal ions in the Io plasma torus with the Galileo spacecraft. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja000159] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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