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Sun W, Turner DL, Zhang Q, Wang S, Egedal J, Leonard T, Slavin JA, Hu Q, Cohen IJ, Genestreti K, Poh G, Gershman DJ, Smith A, Le G, Nakamura R, Giles BL, Ergun RE, Burch JL. Properties and Acceleration Mechanisms of Electrons Up To 200 keV Associated With a Flux Rope Pair and Reconnection X-Lines Around It in Earth's Plasma Sheet. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2022JA030721. [PMID: 37032657 PMCID: PMC10078532 DOI: 10.1029/2022ja030721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/26/2022] [Accepted: 12/02/2022] [Indexed: 06/19/2023]
Abstract
The properties and acceleration mechanisms of electrons (<200 keV) associated with a pair of tailward traveling flux ropes and accompanied reconnection X-lines in Earth's plasma sheet are investigated with MMS measurements. Energetic electrons are enhanced on both boundaries and core of the flux ropes. The power-law spectra of energetic electrons near the X-lines and in flux ropes are harder than those on flux rope boundaries. Theoretical calculations show that the highest energy of adiabatic electrons is a few keV around the X-lines, tens of keV immediately downstream of the X-lines, hundreds of keV on the flux rope boundaries, and a few MeV in the flux rope cores. The X-lines cause strong energy dissipation, which may generate the energetic electron beams around them. The enhanced electron parallel temperature can be caused by the curvature-driven Fermi acceleration and the parallel electric potential. Betatron acceleration due to the magnetic field compression is strong on flux rope boundaries, which enhances energetic electrons in the perpendicular direction. Electrons can be trapped between the flux rope pair due to mirror force and parallel electric potential. Electrostatic structures in the flux rope cores correspond to potential drops up to half of the electron temperature. The energetic electrons and the electron distribution functions in the flux rope cores are suggested to be transported from other dawn-dusk directions, which is a 3-dimensional effect. The acceleration and deceleration of the Betatron and Fermi processes appear alternately indicating that the magnetic field and plasma are turbulent around the flux ropes.
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Affiliation(s)
- Weijie Sun
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - Drew L. Turner
- Space Exploration SectorJohns Hopkins Applied Physics LaboratoryLaurelMDUSA
| | - Qile Zhang
- Los Alamos National LaboratoryLos AlamosNMUSA
| | - Shan Wang
- Department of AstronomyUniversity of MarylandCollege ParkMDUSA
| | - Jan Egedal
- Department of PhysicsUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Trevor Leonard
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderCOUSA
| | - James A. Slavin
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - Qiang Hu
- Department of Space ScienceCenter for Space Plasma and Aeronomic ResearchThe University of Alabama in HuntsvilleHuntsvilleALUSA
| | - Ian J. Cohen
- Space Exploration SectorJohns Hopkins Applied Physics LaboratoryLaurelMDUSA
| | | | - Gangkai Poh
- NASA Goddard Space Flight CenterGreenbeltMDUSA
- Center for Research and Exploration in Space Sciences and Technology IICatholic University of AmericaWashingtonDCUSA
| | | | - Andrew Smith
- Mullard Space Science LaboratoryUniversity College LondonSurreyUK
- Department of Mathematics, Physics and Electrical EngineeringNorthumbria UniversityNewcastle Upon TyneUK
| | - Guan Le
- NASA Goddard Space Flight CenterGreenbeltMDUSA
| | - Rumi Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | | | - Robert E. Ergun
- Department of Astrophysical and Planetary SciencesUniversity of Colorado BoulderBoulderCOUSA
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Sarkango Y, Slavin JA, Jia X, DiBraccio GA, Clark GB, Sun W, Mauk BH, Kurth WS, Hospodarsky GB. Properties of Ion-Inertial Scale Plasmoids Observed by the Juno Spacecraft in the Jovian Magnetotail. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2021JA030181. [PMID: 35865743 PMCID: PMC9286786 DOI: 10.1029/2021ja030181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 06/15/2023]
Abstract
We expand on previous observations of magnetic reconnection in Jupiter's magnetosphere by constructing a survey of ion-inertial scale plasmoids in the Jovian magnetotail. We developed an automated detection algorithm to identify reversals in the B θ component and performed the minimum variance analysis for each identified plasmoid to characterize its helical structure. The magnetic field observations were complemented by data collected using the Juno Waves instrument, which is used to estimate the total electron density, and the JEDI energetic particle detectors. We identified 87 plasmoids with "peak-to-peak" durations between 10 and 300 s. Thirty-one plasmoids possessed a core field and were classified as flux-ropes. The other 56 plasmoids had minimum field strength at their centers and were termed O-lines. Out of the 87 plasmoids, 58 had in situ signatures shorter than 60 s, despite the algorithm's upper limit being 300 s, suggesting that smaller plasmoids with shorter durations were more likely to be detected by Juno. We estimate the diameter of these plasmoids assuming a circular cross section and a travel speed equal to the Alfven speed in the surrounding lobes. Using the electron density inferred by Waves, we contend that these plasmoid diameters were within an order of the local ion-inertial length. Our results demonstrate that magnetic reconnection in the Jovian magnetotail occurs at ion scales like in other space environments. We show that ion-scale plasmoids would need to be released every 0.1 s or less to match the canonical 1 ton/s rate of plasma production due to Io.
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Affiliation(s)
| | | | | | | | - George B. Clark
- Johns Hopkins University – Applied Physics LaboratoryLawrelMDUSA
| | | | - Barry H. Mauk
- Johns Hopkins University – Applied Physics LaboratoryLawrelMDUSA
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Smith AW, Jackman CM, Frohmaier CM, Coxon JC, Slavin JA, Fear RC. Evaluating Single-Spacecraft Observations of Planetary Magnetotails With Simple Monte Carlo Simulations: 1. Spatial Distributions of the Neutral Line. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2018; 123:10109-10123. [PMID: 31008003 PMCID: PMC6472645 DOI: 10.1029/2018ja025958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/26/2018] [Accepted: 12/01/2018] [Indexed: 06/09/2023]
Abstract
A simple Monte Carlo model is presented that considers the effects of spacecraft orbital sampling on the inferred distribution of magnetic flux ropes, generated through magnetic reconnection in the magnetotail current sheet. When generalized, the model allows the determination of the number of orbits required to constrain the underlying population of structures: It is able to quantify this as a function of the physical parameters of the structures (e.g., azimuthal extent and probability of generation). The model is shown adapted to the Hermean magnetotail, where the outputs are compared to the results of a recent survey. This comparison suggests that the center of Mercury's neutral line is located dawnward of midnight by 0 . 3 7 - 1 . 02 + 1 . 21 R M and that the flux ropes are most likely to be wide azimuthally (∼50% of the width of the Hermean tail). The downtail location of the neutral line is not self-consistent or in agreement with previous (independent) studies unless dissipation terms are included planetward of the reconnection site; potential physical explanations are discussed. In the future the model could be adapted to other environments, for example, the dayside magnetopause or other planetary magnetotails.
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Affiliation(s)
- A. W. Smith
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Jackman
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Frohmaier
- Institute of Cosmology and GravitationUniversity of PortsmouthPortsmouthUK
| | - J. C. Coxon
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - J. A. Slavin
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - R. C. Fear
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
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Smith AW, Jackman CM, Frohmaier CM, Fear RC, Slavin JA, Coxon JC. Evaluating Single Spacecraft Observations of Planetary Magnetotails With Simple Monte Carlo Simulations: 2. Magnetic Flux Rope Signature Selection Effects. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2018; 123:10124-10138. [PMID: 31008004 PMCID: PMC6472627 DOI: 10.1029/2018ja025959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/25/2018] [Accepted: 11/20/2018] [Indexed: 06/09/2023]
Abstract
A Monte Carlo method of investigating the effects of placing selection criteria on the magnetic signature of in situ encounters with flux ropes is presented. The technique is applied to two recent flux rope surveys of MESSENGER data within the Hermean magnetotail. It is found that the different criteria placed upon the signatures will preferentially identify slightly different subsets of the underlying population. Quantifying the selection biases first allows the distributions of flux rope parameters to be corrected, allowing a more accurate estimation of the intrinsic distributions. This is shown with regard to the distribution of flux rope radii observed. When accounting for the selection criteria, the mean radius of Hermean magnetotail quasi-force-free flux ropes is found to be 58 9 - 269 + 273 km. Second, it is possible to weight the known identifications in order to determine a rate of recurrence that accounts for the presence of the structures that will not be identified. In the case of the Hermean magnetotail, the average rate of quasi-force-free flux ropes is found to 0.12 min-1 when selection effects are accounted for (up from 0.05 min-1 previously inferred from observations).
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Affiliation(s)
- A. W. Smith
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Jackman
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Frohmaier
- Institute of Cosmology and GravitationUniversity of PortsmouthPortsmouthUK
| | - R. C. Fear
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - J. A. Slavin
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - J. C. Coxon
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
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Mukai T, Yamamoto T, Machida S. Dynamics and Kinetic Properties of Plasmoids and Flux Ropes: GEOTAIL Observations. NEW PERSPECTIVES ON THE EARTH'S MAGNETOTAIL 2013. [DOI: 10.1029/gm105p0117] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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Slavin JA. Cluster observations of traveling compression regions in the near-tail. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004ja010878] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Winglee RM. Ion cyclotron and heavy ion effects on reconnection in a global magnetotail. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004ja010385] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Shirai H, Takada TK, Kamide Y, Mukai T. Enhancements of lobe ion density and velocity associated with plasmoids. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001ja900086] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Håland S, Østgaard N, Bjordal J, Stadsnes J, Ullaland S, Wilken B, Yamamoto T, Doke T, Chenette DL, Parks GK, Brittnacher MJ, Reeves GD. Magnetospheric and ionospheric response to a substorm: Geotail HEP-LD and Polar PIXIE observations. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999ja900216] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ieda A, Machida S, Mukai T, Saito Y, Yamamoto T, Nishida A, Terasawa T, Kokubun S. Statistical analysis of the plasmoid evolution with Geotail observations. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97ja03240] [Citation(s) in RCA: 205] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Zong QG, Wilken B, Reeves GD, Daglis IA, Doke T, Iyemori T, Livi S, Maezawa K, Mukai T, Kokubun S, Pu ZY, Ullaland S, Woch J, Lepping R, Yamamoto T. Geotail observations of energetic ion species and magnetic field in plasmoid-like structures in the course of an isolated substorm event. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97ja00076] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Angelopoulos V, Mitchell DG, McEntire RW, Williams DJ, Lui ATY, Krimigis SM, Decker RB, Christon SP, Kokubun S, Yamamoto T, Saito Y, Mukai T, Mozer FS, Tsuruda K, Reeves GD, Hughes WJ, Friis-Christensen E, Troshichev O. Tailward progression of magnetotail acceleration centers: Relationship to substorm current wedge. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96ja01665] [Citation(s) in RCA: 22] [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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Elphinstone RD, Hearn DJ, Cogger LL, Murphree JS, Wright A, Sandahl I, Ohtani S, Newell PT, Klumpar DM, Shapshak M, Potemra TA, Mursula K, Sauvaud JA. The double oval UV auroral distribution: 2. The most poleward arc system and the dynamics of the magnetotail. ACTA ACUST UNITED AC 1995. [DOI: 10.1029/95ja00327] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Owen CJ, Slavin JA, Richardson IG, Murphy N, Hynds RJ. Average motion, structure and orientation of the distant magnetotail determined from remote sensing of the edge of the plasma sheet boundary layer withE> 35 keV ions. ACTA ACUST UNITED AC 1995. [DOI: 10.1029/94ja02417] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Richardson IG, Owen CJ, Cowley SWH, Galvin AB, Sanderson TR, Scholer M, Slavin JA, Zwickl RD. ISEE 3 observations during the CDAW 8 intervals: Case studies of the distant geomagnetic tail covering a wide range of geomagnetic activity. ACTA ACUST UNITED AC 1989. [DOI: 10.1029/ja094ia11p15189] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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