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Phan TD, Verniero JL, Larson D, Lavraud B, Drake JF, Øieroset M, Eastwood JP, Bale SD, Livi R, Halekas JS, Whittlesey PL, Rahmati A, Stansby D, Pulupa M, MacDowall RJ, Szabo PA, Koval A, Desai M, Fuselier SA, Velli M, Hesse M, Pyakurel PS, Maheshwari K, Kasper JC, Stevens JM, Case AW, Raouafi NE. Parker Solar Probe Observations of Solar Wind Energetic Proton Beams Produced by Magnetic Reconnection in the Near-Sun Heliospheric Current Sheet. Geophys Res Lett 2022; 49:e2021GL096986. [PMID: 35864893 PMCID: PMC9286436 DOI: 10.1029/2021gl096986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 06/09/2023]
Abstract
We report observations of reconnection exhausts in the Heliospheric Current Sheet (HCS) during Parker Solar Probe Encounters 08 and 07, at 16 R s and 20 R s , respectively. Heliospheric current sheet (HCS) reconnection accelerated protons to almost twice the solar wind speed and increased the proton core energy by a factor of ∼3, due to the Alfvén speed being comparable to the solar wind flow speed at these near-Sun distances. Furthermore, protons were energized to super-thermal energies. During E08, energized protons were found to have leaked out of the exhaust along separatrix field lines, appearing as field-aligned energetic proton beams in a broad region outside the HCS. Concurrent dropouts of strahl electrons, indicating disconnection from the Sun, provide further evidence for the HCS being the source of the beams. Around the HCS in E07, there were also proton beams but without electron strahl dropouts, indicating that their origin was not the local HCS reconnection exhaust.
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Affiliation(s)
- T. D. Phan
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | | | - D. Larson
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | - B. Lavraud
- Laboratoire d'Astrophysique de BordeauxUniversity BordeauxPessacFrance
- IRAPCNRSCNESUniversité de ToulouseToulouseFrance
| | | | | | | | - S. D. Bale
- SSLUniversity of CaliforniaBerkeleyCAUSA
- Physics DepartmentUniversity of CaliforniaBerkeleyCAUSA
| | - R. Livi
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | | | | | - A. Rahmati
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | - D. Stansby
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
| | - M. Pulupa
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | | | - P. A. Szabo
- NASA Goddard Space Flight CenterGreenbeltMDUSA
| | - A. Koval
- NASA Goddard Space Flight CenterGreenbeltMDUSA
- University of MarylandBaltimore CountyBaltimoreMDUSA
| | - M. Desai
- Southwest Research InstituteSan AntonioTXUSA
| | | | - M. Velli
- University of CaliforniaLos AngelesCAUSA
| | - M. Hesse
- NASA Ames Research CenterMoffett FieldCAUSA
| | | | | | - J. C. Kasper
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | | | - A. W. Case
- Smithsonian Astrophysical ObservatoryCambridgeMAUSA
| | - N. E. Raouafi
- Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
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Adhikari S, Parashar TN, Shay MA, Matthaeus WH, Pyakurel PS, Fordin S, Stawarz JE, Eastwood JP. Energy transfer in reconnection and turbulence. Phys Rev E 2022; 104:065206. [PMID: 35030942 DOI: 10.1103/physreve.104.065206] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 12/03/2021] [Indexed: 11/07/2022]
Abstract
Reconnection and turbulence are two of the most commonly observed dynamical processes in plasmas, but their relationship is still not fully understood. Using 2.5D kinetic particle-in-cell simulations of both strong turbulence and reconnection, we compare the cross-scale transfer of energy in the two systems by analyzing the generalization of the von Kármán Howarth equations for Hall magnetohydrodynamics, a formulation that subsumes the third-order law for steady energy transfer rates. Even though the large scale features are quite different, the finding is that the decomposition of the energy transfer is structurally very similar in the two cases. In the reconnection case, the time evolution of the energy transfer also exhibits a correlation with the reconnection rate. These results provide explicit evidence that reconnection dynamics fundamentally involves turbulence-like energy transfer.
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Affiliation(s)
- S Adhikari
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - T N Parashar
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA.,School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
| | - M A Shay
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA.,Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - W H Matthaeus
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA.,Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - P S Pyakurel
- Space Sciences Laboratory, University of California, Berkeley, Berkeley, California 94720, USA
| | - S Fordin
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - J E Stawarz
- Department of Physics, Imperial College London, SW7 2AZ, United Kingdom
| | - J P Eastwood
- Department of Physics, Imperial College London, SW7 2AZ, United Kingdom
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3
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Pyakurel PS, Shay MA, Drake JF, Phan TD, Cassak PA, Verniero JL. Faster Form of Electron Magnetic Reconnection with a Finite Length X-Line. Phys Rev Lett 2021; 127:155101. [PMID: 34677989 DOI: 10.1103/physrevlett.127.155101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Observations in Earth's turbulent magnetosheath downstream of a quasiparallel bow shock reveal a prevalence of electron-scale current sheets favorable for electron-only reconnection where ions are not coupled to the reconnecting magnetic fields. In small-scale turbulence, magnetic structures associated with intense current sheets are limited in all dimensions. And since the coupling of ions are constrained by a minimum length scale, the dynamics of electron reconnection is likely to be 3D. Here, both 2D and 3D kinetic particle-in-cell simulations are used to investigate electron-only reconnection, focusing on the reconnection rate and associated electron flows. A new form of 3D electron-only reconnection spontaneously develops where the magnetic X-line is localized in the out-of-plane (z) direction. The consequence is an enhancement of the reconnection rate compared with two dimensions, which results from differential mass flux out of the diffusion region along z, enabling a faster inflow velocity and thus a larger reconnection rate. This outflow along z is due to the magnetic tension force in z just as the conventional exhaust tension force, allowing particles to leave the diffusion region efficiently along z unlike the 2D configuration.
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Affiliation(s)
- P S Pyakurel
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA
| | - M A Shay
- University of Delaware, Newark, Delaware 19716, USA
| | - J F Drake
- Department of Physics and the Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
| | - T D Phan
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA
| | - P A Cassak
- Department of Physics and Astronomy and Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - J L Verniero
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA
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Phan TD, Eastwood JP, Shay MA, Drake JF, Sonnerup BUÖ, Fujimoto M, Cassak PA, Øieroset M, Burch JL, Torbert RB, Rager AC, Dorelli JC, Gershman DJ, Pollock C, Pyakurel PS, Haggerty CC, Khotyaintsev Y, Lavraud B, Saito Y, Oka M, Ergun RE, Retino A, Le Contel O, Argall MR, Giles BL, Moore TE, Wilder FD, Strangeway RJ, Russell CT, Lindqvist PA, Magnes W. Publisher Correction: Electron magnetic reconnection without ion coupling in Earth's turbulent magnetosheath. Nature 2019; 569:E9. [PMID: 31073227 DOI: 10.1038/s41586-019-1208-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Change history: In this Letter, the y-axis values in Fig. 3f should go from 4 to -8 (rather than from 4 to -4), the y-axis values in Fig. 3h should appear next to the major tick marks (rather than the minor ticks), and in Fig. 1b, the arrows at the top and bottom of the electron-scale current sheet were going in the wrong direction; these errors have been corrected online.
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Affiliation(s)
- T D Phan
- Space Sciences Laboratory, University of California, Berkeley, CA, USA.
| | - J P Eastwood
- The Blackett Laboratory, Imperial College London, London, UK
| | - M A Shay
- University of Delaware, Newark, DE, USA
| | - J F Drake
- University of Maryland, College Park, MD, USA
| | | | | | - P A Cassak
- West Virginia University, Morgantown, WV, USA
| | - M Øieroset
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - J L Burch
- Southwest Research Institute, San Antonio, TX, USA
| | - R B Torbert
- University of New Hampshire, Durham, NH, USA
| | - A C Rager
- Catholic University of America, Washington, DC, USA.,NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J C Dorelli
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - D J Gershman
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | | | | | | | - B Lavraud
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, Toulouse, France
| | - Y Saito
- ISAS/JAXA, Sagamihara, Japan
| | - M Oka
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - R E Ergun
- University of Colorado LASP, Boulder, CO, USA
| | - A Retino
- CNRS/Ecole Polytechnique, Paris, France
| | | | - M R Argall
- University of New Hampshire, Durham, NH, USA
| | - B L Giles
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - T E Moore
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - F D Wilder
- University of Colorado LASP, Boulder, CO, USA
| | - R J Strangeway
- University of California, Los Angeles, Los Angeles, CA, USA
| | - C T Russell
- University of California, Los Angeles, Los Angeles, CA, USA
| | | | - W Magnes
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
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