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Richard L, Sorriso-Valvo L, Yordanova E, Graham DB, Khotyaintsev YV. Turbulence in Magnetic Reconnection Jets from Injection to Sub-Ion Scales. PHYSICAL REVIEW LETTERS 2024; 132:105201. [PMID: 38518330 DOI: 10.1103/physrevlett.132.105201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 10/02/2023] [Accepted: 02/05/2024] [Indexed: 03/24/2024]
Abstract
We investigate turbulence in magnetic reconnection jets in the Earth's magnetotail using data from the Magnetospheric Multiscale spacecraft. We show that signatures of a limited inertial range are observed in many reconnection jets. The observed turbulence develops on the timescale of a few ion gyroperiods, resulting in intermittent multifractal energy cascade from the characteristic scale of the jet down to the ion scales. We show that at sub-ion scales, the fluctuations are close to monofractal and predominantly kinetic Alfvén waves. The observed energy transfer rate across the inertial range is ∼10^{8} J kg^{-1} s^{-1}, which is the largest reported for space plasmas so far.
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Affiliation(s)
- Louis Richard
- Swedish Institute of Space Physics, Uppsala 751 21, Sweden and Department of Physics and Astronomy, Space and Plasma Physics, Uppsala University, Uppsala 751 20, Sweden
| | - Luca Sorriso-Valvo
- CNR/ISTP-Istituto per la Scienza e la Tecnologia dei Plasmi, 70126 Bari, Italy; Space and Plasma Physics, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 114 28, Sweden; and Swedish Institute of Space Physics, Uppsala 751 21, Sweden
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2
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Oka M, Birn J, Egedal J, Guo F, Ergun RE, Turner DL, Khotyaintsev Y, Hwang KJ, Cohen IJ, Drake JF. Particle Acceleration by Magnetic Reconnection in Geospace. SPACE SCIENCE REVIEWS 2023; 219:75. [PMID: 37969745 PMCID: PMC10630319 DOI: 10.1007/s11214-023-01011-8] [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: 05/04/2023] [Accepted: 10/05/2023] [Indexed: 11/17/2023]
Abstract
Particles are accelerated to very high, non-thermal energies during explosive energy-release phenomena in space, solar, and astrophysical plasma environments. While it has been established that magnetic reconnection plays an important role in the dynamics of Earth's magnetosphere, it remains unclear how magnetic reconnection can further explain particle acceleration to non-thermal energies. Here we review recent progress in our understanding of particle acceleration by magnetic reconnection in Earth's magnetosphere. With improved resolutions, recent spacecraft missions have enabled detailed studies of particle acceleration at various structures such as the diffusion region, separatrix, jets, magnetic islands (flux ropes), and dipolarization front. With the guiding-center approximation of particle motion, many studies have discussed the relative importance of the parallel electric field as well as the Fermi and betatron effects. However, in order to fully understand the particle acceleration mechanism and further compare with particle acceleration in solar and astrophysical plasma environments, there is a need for further investigation of, for example, energy partition and the precise role of turbulence.
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Affiliation(s)
- Mitsuo Oka
- Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, 94720 CA USA
| | - Joachim Birn
- Center for Space Plasma Physics, Space Science Institute, 4765 Walnut Street, Boulder, 80301 CO USA
- Los Alamos National Laboratory, Los Alamos, 87545 NM USA
| | - Jan Egedal
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, 53706 WI USA
| | - Fan Guo
- Los Alamos National Laboratory, Los Alamos, 87545 NM USA
| | - Robert E. Ergun
- Laboratory for Atmospheric and Space Physics, University of Colorado, 1234 Innovation Drive, Boulder, 80303 CO USA
- Department of Astrophysical and Planetary Sciences, University of Colorado, 2000 Colorado Avenue, Boulder, 80309 CO USA
| | - Drew L. Turner
- The Johns Hopkins Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, 20723 MD USA
| | | | - Kyoung-Joo Hwang
- Southwest Research Institute, 6220 Culebra Road, San Antonio, 78238 TX USA
| | - Ian J. Cohen
- The Johns Hopkins Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, 20723 MD USA
| | - James F. Drake
- Department of Physics, The Institute for Physical Science and Technology and The Joint Space Science Institute, University of Maryland, College Park, 20742 MD USA
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Distribution of water phase near the poles of the Moon from gravity aspects. Sci Rep 2022; 12:4501. [PMID: 35296705 PMCID: PMC8927600 DOI: 10.1038/s41598-022-08305-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/07/2022] [Indexed: 11/18/2022] Open
Abstract
Our Moon periodically moves through the magnetic tail of the Earth that contains terrestrial ions of hydrogen and oxygen. A possible density contrast might have been discovered that could be consistent with the presence of water phase of potential terrestrial origin. Using novel gravity aspects (descriptors) derived from harmonic potential coefficients of gravity field of the Moon, we discovered gravity strike angle anomalies that point to water phase locations in the polar regions of the Moon. Our analysis suggests that impact cratering processes were responsible for specific pore space network that were subsequently filled with the water phase filling volumes of permafrost in the lunar subsurface. In this work, we suggest the accumulation of up to ~ 3000 km3 of terrestrial water phase (Earth’s atmospheric escape) now filling the pore spaced regolith, portion of which is distributed along impact zones of the polar regions of the Moon. These unique locations serve as potential resource utilization sites for future landing exploration and habitats (e.g., NASA Artemis Plan objectives).
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Abstract
In the last few decades, solar activity has been diminishing, and so space weather studies need to be revisited with more attention. The physical processes involved in dealing with various space weather parameters have presented a challenge to the scientific community, with a threat of having a serious impact on modern society and humankind. In the present paper, we have reviewed various aspects of space weather and its present understanding. The Sun and the Earth are the two major elements of space weather, so the solar and the terrestrial perspectives are discussed in detail. A variety of space weather effects and their societal as well as anthropogenic aspects are discussed. The impact of space weather on the terrestrial climate is discussed briefly. A few tools (models) to explain the dynamical space environment and its effects, incorporating real-time data for forecasting space weather, are also summarized. The physical relation of the Earth’s changing climate with various long-term changes in the space environment have provided clues to the short-term/long-term changes. A summary and some unanswered questions are presented in the final section.
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Artemyev AV, Clark G, Mauk B, Vogt MF, Zhang XJ. Juno Observations of Heavy Ion Energization During Transient Dipolarizations in Jupiter Magnetotail. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2020; 125:e2020JA027933. [PMID: 32874822 PMCID: PMC7458100 DOI: 10.1029/2020ja027933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/24/2020] [Indexed: 06/11/2023]
Abstract
Transient magnetic reconnection and associated fast plasma flows led by dipolarization fronts play a crucial role in energetic particle acceleration in planetary magnetospheres. Despite large statistical observations on this phenomenon in the Earth's magnetotail, many important characteristics (e.g., mass or charge dependence of acceleration efficiency and acceleration scaling with the spatial scale of the system) of transient reconnection cannot be fully investigated with the limited parameter range of the Earth's magnetotail. The much larger Jovian magnetodisk, filled by a mixture of various heavy ions and protons, provides a unique opportunity for such investigations. In this study, we use recent Juno observations in Jupiter's magnetosphere to examine the properties of reconnection associated dipolarization fronts and charged particle acceleration. High-energy fluxes of sulfur, oxygen, and hydrogen ions show clear mass-dependent acceleration with energy ~ m 1/3. We compare Juno observations with similar observations in the Earth's magnetotail and discuss possible mechanism for the observed ion acceleration.
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Affiliation(s)
- A. V. Artemyev
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA, USA
- Space Research Institute of Russian Academy of Sciences, Moscow, Russia
| | - G. Clark
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - B. Mauk
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - M. F. Vogt
- Center for Space Physics, Boston University, Boston, MA, USA
| | - X.-J. Zhang
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA, USA
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Sitnov M, Birn J, Ferdousi B, Gordeev E, Khotyaintsev Y, Merkin V, Motoba T, Otto A, Panov E, Pritchett P, Pucci F, Raeder J, Runov A, Sergeev V, Velli M, Zhou X. Explosive Magnetotail Activity. SPACE SCIENCE REVIEWS 2019; 215:31. [PMID: 31178609 PMCID: PMC6528807 DOI: 10.1007/s11214-019-0599-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/27/2019] [Indexed: 06/01/2023]
Abstract
Modes and manifestations of the explosive activity in the Earth's magnetotail, as well as its onset mechanisms and key pre-onset conditions are reviewed. Two mechanisms for the generation of the pre-onset current sheet are discussed, namely magnetic flux addition to the tail lobes, or other high-latitude perturbations, and magnetic flux evacuation from the near-Earth tail associated with dayside reconnection. Reconnection onset may require stretching and thinning of the sheet down to electron scales. It may also start in thicker sheets in regions with a tailward gradient of the equatorial magnetic field B z ; in this case it begins as an ideal-MHD instability followed by the generation of bursty bulk flows and dipolarization fronts. Indeed, remote sensing and global MHD modeling show the formation of tail regions with increased B z , prone to magnetic reconnection, ballooning/interchange and flapping instabilities. While interchange instability may also develop in such thicker sheets, it may grow more slowly compared to tearing and cause secondary reconnection locally in the dawn-dusk direction. Post-onset transients include bursty flows and dipolarization fronts, micro-instabilities of lower-hybrid-drift and whistler waves, as well as damped global flux tube oscillations in the near-Earth region. They convert the stretched tail magnetic field energy into bulk plasma acceleration and collisionless heating, excitation of a broad spectrum of plasma waves, and collisional dissipation in the ionosphere. Collisionless heating involves ion reflection from fronts, Fermi, betatron as well as other, non-adiabatic, mechanisms. Ionospheric manifestations of some of these magnetotail phenomena are discussed. Explosive plasma phenomena observed in the laboratory, the solar corona and solar wind are also discussed.
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Affiliation(s)
- Mikhail Sitnov
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | | | - Evgeny Gordeev
- Earth’s Physics Department, Saint Petersburg State University, St. Petersburg, Russia
| | | | - Viacheslav Merkin
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - Tetsuo Motoba
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | - Evgeny Panov
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - Philip Pritchett
- Department of Physics and Astronomy, University of California, Los Angeles, CA USA
| | - Fulvia Pucci
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, 509-5292 Japan
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ USA
| | - Joachim Raeder
- Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH USA
| | - Andrei Runov
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA USA
| | - Victor Sergeev
- Earth’s Physics Department, Saint Petersburg State University, St. Petersburg, Russia
| | - Marco Velli
- University of California Los Angeles, Los Angeles, CA 90095 USA
| | - Xuzhi Zhou
- School of Earth and Space Sciences, Peking University, Beijing, 100871 China
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Abstract
The problem of studying anomalous superdiffusive transport by means of fractional transport equations is considered. We concentrate on the case when an advection flow is present (since this corresponds to many actual plasma configurations), as well as on the case when a boundary is also present. We propose that the presence of a boundary can be taken into account by adopting the Caputo fractional derivatives for the side of the boundary (here, the left side), while the Riemann-Liouville derivative is used for the unbounded side (here, the right side). These derivatives are used to write the fractional diffusion–advection equation. We look for solutions in the steady-state case, as such solutions are of practical interest for comparison with observations both in laboratory and astrophysical plasmas. It is shown that the solutions in the completely asymmetric cases have the form of Mittag-Leffler functions in the case of the left fractional contribution, and the form of an exponential decay in the case of the right fractional contribution. Possible applications to space plasmas are discussed.
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Kiehas SA, Volkonskaya NN, Semenov VS, Erkaev NV, Kubyshkin IV, Zaitsev IV. Large-scale energy budget of impulsive magnetic reconnection: Theory and simulation. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2017; 122:3212-3231. [PMID: 28529838 PMCID: PMC5413852 DOI: 10.1002/2016ja023169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 02/10/2017] [Accepted: 02/14/2017] [Indexed: 06/07/2023]
Abstract
We evaluate the large-scale energy budget of magnetic reconnection utilizing an analytical time-dependent impulsive reconnection model and a numerical 2-D MHD simulation. With the generalization to compressible plasma, we can investigate changes in the thermal, kinetic, and magnetic energies. We study these changes in three different regions: (a) the region defined by the outflowing plasma (outflow region, OR), (b) the region of compressed magnetic fields above/below the OR (traveling compression region, TCR), and (c) the region trailing the OR and TCR (wake). For incompressible plasma, we find that the decrease inside the OR is compensated by the increase in kinetic energy. However, for the general compressible case, the decrease in magnetic energy inside the OR is not sufficient to explain the increase in thermal and kinetic energy. Hence, energy from other regions needs to be considered. We find that the decrease in thermal and magnetic energy in the wake, together with the decrease in magnetic energy inside the OR, is sufficient to feed the increase in kinetic and thermal energies in the OR and the increase in magnetic and thermal energies inside the TCR. That way, the energy budget is balanced, but consequently, not all magnetic energy is converted into kinetic and thermal energies of the OR. Instead, a certain fraction gets transfered into the TCR. As an upper limit of the efficiency of reconnection (magnetic energy → kinetic energy) we find ηeff=1/2. A numerical simulation is used to include a finite thickness of the current sheet, which shows the importance of the pressure gradient inside the OR for the conversion of kinetic energy into thermal energy.
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Affiliation(s)
- S. A. Kiehas
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - N. N. Volkonskaya
- Institute of PhysicsSt. Petersburg State UniversitySt. PetersburgRussia
| | - V. S. Semenov
- Institute of PhysicsSt. Petersburg State UniversitySt. PetersburgRussia
| | - N. V. Erkaev
- Institute of Computational ModellingRussian Academy of Sciences, Siberian BranchKrasnoyarskRussia
- Department of Computational PhysicsSiberian Federal UniversityKrasnoyarskRussia
| | - I. V. Kubyshkin
- Institute of PhysicsSt. Petersburg State UniversitySt. PetersburgRussia
| | - I. V. Zaitsev
- Institute of PhysicsSt. Petersburg State UniversitySt. PetersburgRussia
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Panov EV, Baumjohann W, Wolf RA, Nakamura R, Angelopoulos V, Weygand JM, Kubyshkina MV. Magnetotail energy dissipation during an auroral substorm. NATURE PHYSICS 2016; 12:1158-1163. [PMID: 27917231 PMCID: PMC5131847 DOI: 10.1038/nphys3879] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 08/04/2016] [Indexed: 06/01/2023]
Abstract
Violent releases of space plasma energy from the Earth's magnetotail during substorms produce strong electric currents and bright aurora. But what modulates these currents and aurora and controls dissipation of the energy released in the ionosphere? Using data from the THEMIS fleet of satellites and ground-based imagers and magnetometers, we show that plasma energy dissipation is controlled by field-aligned currents (FACs) produced and modulated during magnetotail topology change and oscillatory braking of fast plasma jets at 10-14 Earth radii in the nightside magnetosphere. FACs appear in regions where plasma sheet pressure and flux tube volume gradients are non-collinear. Faster tailward expansion of magnetotail dipolarization and subsequent slower inner plasma sheet restretching during substorm expansion and recovery phases cause faster poleward then slower equatorward movement of the substorm aurora. Anharmonic radial plasma oscillations build up displaced current filaments and are responsible for discrete longitudinal auroral arcs that move equatorward at a velocity of about 1km/s. This observed auroral activity appears sufficient to dissipate the released energy.
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Affiliation(s)
- E V Panov
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - W Baumjohann
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - R A Wolf
- Physics and Astronomy Department, Rice University, Houston, Texas, USA
| | - R Nakamura
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - V Angelopoulos
- Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, USA
| | - J M Weygand
- Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, USA
| | - M V Kubyshkina
- St. Petersburg State University, St. Petersburg, Russian Federation
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Artemyev AV, Vasiliev AA. Resonant ion acceleration by plasma jets: Effects of jet breaking and the magnetic-field curvature. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:053104. [PMID: 26066269 DOI: 10.1103/physreve.91.053104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Indexed: 06/04/2023]
Abstract
In this paper we consider resonant ion acceleration by a plasma jet originating from the magnetic reconnection region. Such jets propagate in the background magnetic field with significantly curved magnetic-field lines. Decoupling of ion and electron motions at the leading edge of the jet results in generation of strong electrostatic fields. Ions can be trapped by this field and get accelerated along the jet front. This mechanism of resonant acceleration resembles surfing acceleration of charged particles at a shock wave. To describe resonant acceleration of ions, we use adiabatic theory of resonant phenomena. We show that particle motion along the curved field lines significantly influences the acceleration rate. The maximum gain of energy is determined by the particle's escape from the system due to this motion. Applications of the proposed mechanism to charged-particle acceleration in the planetary magnetospheres and the solar corona are discussed.
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Affiliation(s)
- A V Artemyev
- Space Research Institute (IKI) 117997, 84/32 Profsoyuznaya Str, Moscow, Russia
| | - A A Vasiliev
- Space Research Institute (IKI) 117997, 84/32 Profsoyuznaya Str, Moscow, Russia
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Yamada M, Yoo J, Jara-Almonte J, Ji H, Kulsrud RM, Myers CE. Conversion of magnetic energy in the magnetic reconnection layer of a laboratory plasma. Nat Commun 2014; 5:4774. [DOI: 10.1038/ncomms5774] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/23/2014] [Indexed: 11/09/2022] Open
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Artemyev AV. Charged-particle acceleration in braking plasma jets. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:033108. [PMID: 24730957 DOI: 10.1103/physreve.89.033108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Indexed: 06/03/2023]
Abstract
In this paper we describe the mechanism of the charged particle acceleration in space plasma systems. We consider the interaction of nonrelativistic particles with a sub-Alfvenic plasma jet originated from the magnetic reconnection. The sharp front with increased magnetic field amplitude forms in the jet leading edge. Propagation of the jet in the inhomogeneous background plasma results in front braking. We show that particles can interact with this front in a resonance manner. Synchronization of particle reflections from the front and the front braking provides the stable trapping of particles in the vicinity of the front. This trapping supports the effective particle acceleration along the front. The mechanism of acceleration is potentially important due to the prevalence of the magnetic reconnection in space and astrophysical plasmas.
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