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Dougherty MK, Cao H, Khurana KK, Hunt GJ, Provan G, Kellock S, Burton ME, Burk TA, Bunce EJ, Cowley SWH, Kivelson MG, Russell CT, Southwood DJ. Saturn’s magnetic field revealed by the Cassini Grand Finale. Science 2018; 362:362/6410/eaat5434. [DOI: 10.1126/science.aat5434] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 09/05/2018] [Indexed: 11/03/2022]
Abstract
During 2017, the Cassini fluxgate magnetometer made in situ measurements of Saturn’s magnetic field at distances ~2550 ± 1290 kilometers above the 1-bar surface during 22 highly inclined Grand Finale orbits. These observations refine the extreme axisymmetry of Saturn’s internal magnetic field and show displacement of the magnetic equator northward from the planet’s physical equator. Persistent small-scale magnetic structures, corresponding to high-degree (>3) axisymmetric magnetic moments, were observed. This suggests secondary shallow dynamo action in the semiconducting region of Saturn’s interior. Some high-degree magnetic moments could arise from strong high-latitude concentrations of magnetic flux within the planet’s deep dynamo. A strong field-aligned current (FAC) system is located between Saturn and the inner edge of its D-ring, with strength comparable to the high-latitude auroral FACs.
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Jia X, Kivelson MG. Driving Saturn's magnetospheric periodicities from the upper atmosphere/ionosphere: Magnetotail response to dual sources. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012ja018183] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Badman SV, Andrews DJ, Cowley SWH, Lamy L, Provan G, Tao C, Kasahara S, Kimura T, Fujimoto M, Melin H, Stallard T, Brown RH, Baines KH. Rotational modulation and local time dependence of Saturn's infrared H3+auroral intensity. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012ja017990] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Szego K, Nemeth Z, Erdos G, Foldy L, Bebesi Z, Thomsen M, Delapp D. Location of the magnetodisk in the nightside outer magnetosphere of Saturn near equinox based on ion densities. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012ja017817] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Andrews DJ, Cowley SWH, Dougherty MK, Lamy L, Provan G, Southwood DJ. Planetary period oscillations in Saturn's magnetosphere: Evolution of magnetic oscillation properties from southern summer to post-equinox. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011ja017444] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Provan G, Andrews DJ, Arridge CS, Coates AJ, Cowley SWH, Cox G, Dougherty MK, Jackman CM. Dual periodicities in planetary-period magnetic field oscillations in Saturn's tail. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011ja017104] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Arridge CS, André N, Khurana KK, Russell CT, Cowley SWH, Provan G, Andrews DJ, Jackman CM, Coates AJ, Sittler EC, Dougherty MK, Young DT. Periodic motion of Saturn's nightside plasma sheet. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011ja016827] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- C. S. Arridge
- Mullard Space Science Laboratory; University College London; Dorking UK
- Centre for Planetary Sciences at UCL/Birkbeck; London UK
| | - N. André
- Institut de Recherche en Astrophysique et Planétologie; CNRS; Toulouse France
- Institut de Recherche en Astrophysique et Planétologie; Université de Toulouse, UPS-OMP; Toulouse France
| | - K. K. Khurana
- Institute for Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - C. T. Russell
- Institute for Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - S. W. H. Cowley
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - G. Provan
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - D. J. Andrews
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - C. M. Jackman
- Centre for Planetary Sciences at UCL/Birkbeck; London UK
- Blackett Laboratory; Imperial College London; London UK
- Department of Physics and Astronomy; University College London; London UK
| | - A. J. Coates
- Mullard Space Science Laboratory; University College London; Dorking UK
- Centre for Planetary Sciences at UCL/Birkbeck; London UK
| | - E. C. Sittler
- NASA Goddard Space Flight Center; Greenbelt Maryland USA
| | | | - D. T. Young
- Southwest Research Institute; San Antonio Texas USA
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Andrews DJ, Cecconi B, Cowley SWH, Dougherty MK, Lamy L, Provan G, Zarka P. Planetary period oscillations in Saturn's magnetosphere: Evidence in magnetic field phase data for rotational modulation of Saturn kilometric radiation emissions. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011ja016636] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- D. J. Andrews
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - B. Cecconi
- LESIA, Observatoire de Paris, CNRS, UPMC; Université Paris VII - Denis Diderot; Meudon France
| | - S. W. H. Cowley
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | | | - L. Lamy
- LESIA, Observatoire de Paris, CNRS, UPMC; Université Paris VII - Denis Diderot; Meudon France
| | - G. Provan
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - P. Zarka
- LESIA, Observatoire de Paris, CNRS, UPMC; Université Paris VII - Denis Diderot; Meudon France
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Provan G, Andrews DJ, Cecconi B, Cowley SWH, Dougherty MK, Lamy L, Zarka PM. Magnetospheric period magnetic field oscillations at Saturn: Equatorial phase “jitter” produced by superposition of southern and northern period oscillations. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010ja016213] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- G. Provan
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - D. J. Andrews
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - B. Cecconi
- LESIA, Observatoire de Paris, CNRS, UPMC; Université Paris Diderot; Meudon France
| | - S. W. H. Cowley
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | | | - L. Lamy
- LESIA, Observatoire de Paris, CNRS, UPMC; Université Paris Diderot; Meudon France
| | - P. M. Zarka
- LESIA, Observatoire de Paris, CNRS, UPMC; Université Paris Diderot; Meudon France
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