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Yang L, He J, Verscharen D, Li H, Bowen TA, Bale SD, Wu H, Li W, Wang Y, Zhang L, Feng X, Wu Z. Energy transfer of imbalanced Alfvénic turbulence in the heliosphere. Nat Commun 2023; 14:7955. [PMID: 38040682 PMCID: PMC10692179 DOI: 10.1038/s41467-023-43273-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 11/03/2023] [Indexed: 12/03/2023] Open
Abstract
Imbalanced Alfvénic turbulence is a universal process playing a crucial role in energy transfer in space, astrophysical, and laboratory plasmas. A fundamental and long-lasting question about the imbalanced Alfvénic turbulence is how and through which mechanism the energy transfers between scales. Here, we show that the energy transfer of imbalanced Alfvénic turbulence is completed by coherent interactions between Alfvén waves and co-propagating anomalous fluctuations. These anomalous fluctuations are generated by nonlinear couplings instead of linear reflection. We also reveal that the energy transfer of the waves and the anomalous fluctuations is carried out mainly through local-scale and large-scale nonlinear interactions, respectively, responsible for their bifurcated power-law spectra. This work unveils the energy transfer physics of imbalanced Alfvénic turbulence, and advances the understanding of imbalanced Alfvénic turbulence observed by Parker Solar Probe in the inner heliosphere.
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Affiliation(s)
- Liping Yang
- SIGMA Weather Group, State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, 100190, Beijing, People's Republic of China
| | - Jiansen He
- School of Earth and Space Sciences, Peking University, 100871, Beijing, People's Republic of China.
| | - Daniel Verscharen
- Mullard Space Science Laboratory, University College London, Surrey, RH5 6NT, UK
| | - Hui Li
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Trevor A Bowen
- Space Sciences Laboratory, University of California, Berkeley, CA, 94720-7450, USA
| | - Stuart D Bale
- Space Sciences Laboratory, University of California, Berkeley, CA, 94720-7450, USA
- Physics Department, University of California, Berkeley, CA, 94720-7300, USA
| | - Honghong Wu
- School of Electronic Information, Wuhan University, 430072, Wuhan, People's Republic of China
| | - Wenya Li
- State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, 100190, Beijing, People's Republic of China
| | - Ying Wang
- School of Earth and Space Sciences, Peking University, 100871, Beijing, People's Republic of China
| | - Lei Zhang
- China Academy of Aerospace Science and Innovation, 100190, Beijing, People's Republic of China
| | - Xueshang Feng
- SIGMA Weather Group, State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, 100190, Beijing, People's Republic of China
| | - Ziqi Wu
- School of Earth and Space Sciences, Peking University, 100871, Beijing, People's Republic of China
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Turc L, Roberts OW, Verscharen D, Dimmock AP, Kajdič P, Palmroth M, Pfau-Kempf Y, Johlander A, Dubart M, Kilpua EKJ, Soucek J, Takahashi K, Takahashi N, Battarbee M, Ganse U. Transmission of foreshock waves through Earth's bow shock. Nat Phys 2022; 19:78-86. [PMID: 36687291 PMCID: PMC9845118 DOI: 10.1038/s41567-022-01837-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/14/2022] [Indexed: 06/17/2023]
Abstract
The Earth's magnetosphere and its bow shock, which is formed by the interaction of the supersonic solar wind with the terrestrial magnetic field, constitute a rich natural laboratory enabling in situ investigations of universal plasma processes. Under suitable interplanetary magnetic field conditions, a foreshock with intense wave activity forms upstream of the bow shock. So-called 30 s waves, named after their typical period at Earth, are the dominant wave mode in the foreshock and play an important role in modulating the shape of the shock front and affect particle reflection at the shock. These waves are also observed inside the magnetosphere and down to the Earth's surface, but how they are transmitted through the bow shock remains unknown. By combining state-of-the-art global numerical simulations and spacecraft observations, we demonstrate that the interaction of foreshock waves with the shock generates earthward-propagating, fast-mode waves, which reach the magnetosphere. These findings give crucial insight into the interaction of waves with collisionless shocks in general and their impact on the downstream medium.
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Affiliation(s)
- L. Turc
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - O. W. Roberts
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - D. Verscharen
- Mullard Space Science Laboratory, University College London, Dorking, UK
| | | | - P. Kajdič
- Departamento de Ciencias Espaciales, Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - M. Palmroth
- Department of Physics, University of Helsinki, Helsinki, Finland
- Finnish Meteorological Institute, Helsinki, Finland
| | - Y. Pfau-Kempf
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - A. Johlander
- Department of Physics, University of Helsinki, Helsinki, Finland
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - M. Dubart
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - E. K. J. Kilpua
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - J. Soucek
- Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - K. Takahashi
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - N. Takahashi
- Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo, Japan
- Radio Research Institute, National Institute of Information and Communication Technology, Tokyo, Japan
| | - M. Battarbee
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - U. Ganse
- Department of Physics, University of Helsinki, Helsinki, Finland
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Verscharen D, Wicks RT, Alexandrova O, Bruno R, Burgess D, Chen CHK, D’Amicis R, De Keyser J, de Wit TD, Franci L, He J, Henri P, Kasahara S, Khotyaintsev Y, Klein KG, Lavraud B, Maruca BA, Maksimovic M, Plaschke F, Poedts S, Reynolds CS, Roberts O, Sahraoui F, Saito S, Salem CS, Saur J, Servidio S, Stawarz JE, Štverák Š, Told D. A Case for Electron-Astrophysics. Exp Astron (Dordr) 2021; 54:473-519. [PMID: 36915623 PMCID: PMC9998602 DOI: 10.1007/s10686-021-09761-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 05/07/2021] [Indexed: 06/18/2023]
Abstract
The smallest characteristic scales, at which electron dynamics determines the plasma behaviour, are the next frontier in space and astrophysical plasma research. The analysis of astrophysical processes at these scales lies at the heart of the research theme of electron-astrophysics. Electron scales are the ultimate bottleneck for dissipation of plasma turbulence, which is a fundamental process not understood in the electron-kinetic regime. In addition, plasma electrons often play an important role for the spatial transfer of thermal energy due to the high heat flux associated with their velocity distribution. The regulation of this electron heat flux is likewise not understood. By focussing on these and other fundamental electron processes, the research theme of electron-astrophysics links outstanding science questions of great importance to the fields of space physics, astrophysics, and laboratory plasma physics. In this White Paper, submitted to ESA in response to the Voyage 2050 call, we review a selection of these outstanding questions, discuss their importance, and present a roadmap for answering them through novel space-mission concepts.
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Affiliation(s)
- Daniel Verscharen
- Mullard Space Science Laboratory, University College London, Dorking, UK
- Space Science Center, University of New Hampshire, Durham, NH USA
| | - Robert T. Wicks
- Mullard Space Science Laboratory, University College London, Dorking, UK
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle-upon-Tyne, UK
| | - Olga Alexandrova
- Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique, Observatoire de Paris-Meudon, Paris, France
| | - Roberto Bruno
- Instituto di Astrofisica e Planetologia Spaziali, INAF, Rome, Italy
| | - David Burgess
- School of Physics and Astronomy, Queen Mary University of London, London, UK
| | | | | | - Johan De Keyser
- Royal Belgian Institute for Space Aeronomy, Brussels, Belgium
| | - Thierry Dudok de Wit
- Laboratoire de Physique et Chimie de l’Environment et de l’Espace, CNRS, University of Orléans and CNES, Orléans, France
| | - Luca Franci
- School of Physics and Astronomy, Queen Mary University of London, London, UK
- Osservatorio Astrofisico di Arcetri, INAF, Firenze, Italy
| | - Jiansen He
- School of Earth and Space Sciences, Peking University, Beijing, China
| | - Pierre Henri
- Laboratoire de Physique et Chimie de l’Environment et de l’Espace, CNRS, University of Orléans and CNES, Orléans, France
- CNRS, UCA, OCA, Lagrange, Nice, France
| | - Satoshi Kasahara
- Department of Earth and Planetary Science, University of Tokyo, Tokyo, Japan
| | | | - Kristopher G. Klein
- Lunar and Planetary Laboratory and Department of Planetary Sciences, University of Arizona, Tucson, AZ USA
| | - Benoit Lavraud
- Laboratoire d’astrophysique de Bordeaux, Université de Bordeaux, CNRS, Pessac, France
- Institut de Recherche en Astrophysique et Planétologie, CNRS, UPS, CNES, Université de Toulouse, Toulouse, France
| | - Bennett A. Maruca
- Department of Physics and Astronomy, Bartol Research Institute, University of Delaware, Newark, DE USA
| | - Milan Maksimovic
- Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique, Observatoire de Paris-Meudon, Paris, France
| | | | - Stefaan Poedts
- Centre for Mathematical Plasma Astrophysics, KU Leuven, Leuven, Belgium
- Institute of Physics, University of Maria Curie-Skłodowska, Lublin, Poland
| | | | - Owen Roberts
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - Fouad Sahraoui
- Laboratoire de Physique des Plasmas, CNRS, École Polytechnique, Sorbonne Université, Observatoire de Paris-Meudon, Paris Saclay, Palaiseau, France
| | - Shinji Saito
- Space Environment Laboratory, National Institute of Information and Communications Technology, Tokyo, Japan
| | - Chadi S. Salem
- Space Sciences Laboratory, University of California, Berkeley, CA USA
| | - Joachim Saur
- Institut für Geophysik und Meteorologie, University of Cologne, Cologne, Germany
| | - Sergio Servidio
- Department of Physics, Università della Calabria, Rende, Italy
| | | | - Štěpán Štverák
- Astronomical Institute and Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Daniel Told
- Max Planck Institute for Plasma Physics, Garching, Germany
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Wilson LB, Brosius AL, Gopalswamy N, Nieves‐Chinchilla T, Szabo A, Hurley K, Phan T, Kasper JC, Lugaz N, Richardson IG, Chen CHK, Verscharen D, Wicks RT, TenBarge JM. A Quarter Century of Wind Spacecraft Discoveries. Rev Geophys 2021; 59:e2020RG000714. [PMCID: PMC9285980 DOI: 10.1029/2020rg000714] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/29/2021] [Accepted: 03/05/2021] [Indexed: 06/13/2023]
Abstract
The Wind spacecraft, launched on November 1, 1994, is a critical element in NASA’s Heliophysics System Observatory (HSO)—a fleet of spacecraft created to understand the dynamics of the Sun‐Earth system. The combination of its longevity (>25 years in service), its diverse complement of instrumentation, and high resolution and accurate measurements has led to it becoming the “standard candle” of solar wind measurements. Wind has over 55 selectable public data products with over ∼1,100 total data variables (including OMNI data products) on SPDF/CDAWeb alone. These data have led to paradigm shifting results in studies of statistical solar wind trends, magnetic reconnection, large‐scale solar wind structures, kinetic physics, electromagnetic turbulence, the Van Allen radiation belts, coronal mass ejection topology, interplanetary and interstellar dust, the lunar wake, solar radio bursts, solar energetic particles, and extreme astrophysical phenomena such as gamma‐ray bursts. This review introduces the mission and instrument suites then discusses examples of the contributions by Wind to these scientific topics that emphasize its importance to both the fields of heliophysics and astrophysics. Wind has made seminal advances to the fields of astrophysics, turbulence, kinetic physics, magnetic reconnection, and the radiation belts Wind pioneered the study of the source and evolution of solar radio emissions below 15 MHz Wind revolutionized our understanding of coronal mass ejections, their internal magnetic structure, and evolution
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Affiliation(s)
- Lynn B. Wilson
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
| | - Alexandra L. Brosius
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
- Department of Meteorology and Atmospheric ScienceThe Pennsylvania State UniversityUniversity ParkPAUSA
| | | | | | - Adam Szabo
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
| | - Kevin Hurley
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCAUSA
| | - Tai Phan
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCAUSA
| | - Justin C. Kasper
- School of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborAnn ArborMIUSA
| | - Noé Lugaz
- Space Science CenterInstitute for the Study of EarthOceans, and SpaceUniversity of New HampshireDurhamNHUSA
- Department of PhysicsUniversity of New HampshireDurhamNHUSA
| | - Ian G. Richardson
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
- Department of AstronomyUniversity of MarylandCollege ParkMDUSA
| | | | - Daniel Verscharen
- Space Science CenterInstitute for the Study of EarthOceans, and SpaceUniversity of New HampshireDurhamNHUSA
- Mullard Space Science LaboratoryUniversity College LondonSurreyUK
| | - Robert T. Wicks
- Department of MathematicsPhysics and Electrical EngineeringNorthumbria University: Newcastle upon TyneTyne and WearUK
| | - Jason M. TenBarge
- University of MarylandCollege ParkMDUSA
- Department of Astrophysical SciencesPrinceton UniversityPrincetonNJUSA
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Nicolaou G, Wicks R, Livadiotis G, Verscharen D, Owen C, Kataria D. Determining the Bulk Parameters of Plasma Electrons from Pitch-Angle Distribution Measurements. Entropy (Basel) 2020; 22:e22010103. [PMID: 33285879 PMCID: PMC7516406 DOI: 10.3390/e22010103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 12/02/2022]
Abstract
Electrostatic analysers measure the flux of plasma particles in velocity space and determine their velocity distribution function. There are occasions when science objectives require high time-resolution measurements, and the instrument operates in short measurement cycles, sampling only a portion of the velocity distribution function. One such high-resolution measurement strategy consists of sampling the two-dimensional pitch-angle distributions of the plasma particles, which describes the velocities of the particles with respect to the local magnetic field direction. Here, we investigate the accuracy of plasma bulk parameters from such high-resolution measurements. We simulate electron observations from the Solar Wind Analyser’s (SWA) Electron Analyser System (EAS) on board Solar Orbiter. We show that fitting analysis of the synthetic datasets determines the plasma temperature and kappa index of the distribution within 10% of their actual values, even at large heliocentric distances where the expected solar wind flux is very low. Interestingly, we show that although measurement points with zero counts are not statistically significant, they provide information about the particle distribution function which becomes important when the particle flux is low. We also examine the convergence of the fitting algorithm for expected plasma conditions and discuss the sources of statistical and systematic uncertainties.
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Affiliation(s)
- Georgios Nicolaou
- Department of Space and Climate Physics, Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT, UK; (R.W.); (D.V.); (C.O.); (D.K.)
- Correspondence:
| | - Robert Wicks
- Department of Space and Climate Physics, Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT, UK; (R.W.); (D.V.); (C.O.); (D.K.)
| | | | - Daniel Verscharen
- Department of Space and Climate Physics, Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT, UK; (R.W.); (D.V.); (C.O.); (D.K.)
- Space Science Center, University of New Hampshire, Durham, NH 03824, USA
| | - Christopher Owen
- Department of Space and Climate Physics, Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT, UK; (R.W.); (D.V.); (C.O.); (D.K.)
| | - Dhiren Kataria
- Department of Space and Climate Physics, Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT, UK; (R.W.); (D.V.); (C.O.); (D.K.)
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7
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Abstract
The solar wind is a magnetized plasma and as such exhibits collective plasma behavior associated with its characteristic spatial and temporal scales. The characteristic length scales include the size of the heliosphere, the collisional mean free paths of all species, their inertial lengths, their gyration radii, and their Debye lengths. The characteristic timescales include the expansion time, the collision times, and the periods associated with gyration, waves, and oscillations. We review the past and present research into the multi-scale nature of the solar wind based on in-situ spacecraft measurements and plasma theory. We emphasize that couplings of processes across scales are important for the global dynamics and thermodynamics of the solar wind. We describe methods to measure in-situ properties of particles and fields. We then discuss the role of expansion effects, non-equilibrium distribution functions, collisions, waves, turbulence, and kinetic microinstabilities for the multi-scale plasma evolution.
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Affiliation(s)
- Daniel Verscharen
- Mullard Space Science Laboratory, University College London, Dorking, RH5 6NT UK
- Space Science Center, University of New Hampshire, Durham, NH 03824 USA
| | - Kristopher G. Klein
- Lunar and Planetary Laboratory and Department of Planetary Sciences, University of Arizona, Tucson, AZ 85719 USA
| | - Bennett A. Maruca
- Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 USA
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Hoppock IW, Chandran BDG, Klein KG, Mallet A, Verscharen D. Stochastic proton heating by kinetic-Alfvén-wave turbulence in moderately high- β plasmas. J Plasma Phys 2018; 84:905840615. [PMID: 30948860 PMCID: PMC6443259 DOI: 10.1017/s0022377818001277] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Stochastic heating refers to an increase in the average magnetic moment of charged particles interacting with electromagnetic fluctuations whose frequencies are much smaller than the particles' cyclotron frequencies. This type of heating arises when the amplitude of the gyroscale fluctuations exceeds a certain threshold, causing particle orbits in the plane perpendicular to the magnetic field to become stochastic rather than nearly periodic. We consider the stochastic heating of protons by Alfvén-wave (AW) and kinetic-Alfvén-wave (KAW) turbulence, which may make an important contribution to the heating of the solar wind. Using phenomenological arguments, we derive the stochastic-proton-heating rate in plasmas in which β p ∼ 1 - 30, where β p is the ratio of the proton pressure to the magnetic pressure. (We do not consider the β p ≳ 30 regime, in which KAWs at the proton gyroscale become non-propagating.) We test our formula for the stochastic-heating rate by numerically tracking test-particle protons interacting with a spectrum of randomly phased AWs and KAWs. Previous studies have demonstrated that at β p ≲1, particles are energized primarily by time variations in the electrostatic potential and thermal-proton gyro-orbits are stochasticized primarily by gyroscale fluctuations in the electrostatic potential. In contrast, at β p ≳ 1, particles are energized primarily by the solenoidal component of the electric field and thermal-proton gyro-orbits are stochasticized primarily by gyroscale fluctuations in the magnetic field.
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Affiliation(s)
- Ian W. Hoppock
- Space Science Center, University of New Hampshire, Durham, NH, 03824, USA
| | | | - Kristopher G. Klein
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, 85719, USA
- CLASP, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Alfred Mallet
- Space Science Center, University of New Hampshire, Durham, NH, 03824, USA
- Space Sciences Laboratory, University of California, Berkeley, CA, 94720, USA
| | - Daniel Verscharen
- Space Science Center, University of New Hampshire, Durham, NH, 03824, USA
- Mullard Space Science Laboratory, University College London, Dorking, RH5 6NT, UK
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Riquelme MA, Quataert E, Verscharen D. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/800/1/27] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Verscharen D, Marsch E, Motschmann U, Müller J. Parametric decay of oblique Alfvén waves in two-dimensional hybrid simulations. Phys Rev E Stat Nonlin Soft Matter Phys 2012; 86:027401. [PMID: 23005891 DOI: 10.1103/physreve.86.027401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 07/23/2012] [Indexed: 06/01/2023]
Abstract
Certain types of plasma waves are known to become parametrically unstable under specific plasma conditions, in which the pump wave will decay into several daughter waves with different wavenumbers and frequencies. In the past, the related plasma instabilities have been treated analytically for various parameter regimes and by use of various numerical methods, yet the oblique propagation with respect to the background magnetic field has rarely been dealt with in two dimensions, mainly because of the high computational demand. Here we present a hybrid-simulation study of the parametric decay of a moderately oblique Alfvén wave having elliptical polarization. It is found that such a compressive wave can decay into waves with higher and lower wavenumbers than the pump.
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Affiliation(s)
- D Verscharen
- Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany.
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