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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] [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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Teodorescu E, Echim M. Open-Source Software Analysis Tool to Investigate Space Plasma Turbulence and Nonlinear DYNamics (ODYN). EARTH AND SPACE SCIENCE (HOBOKEN, N.J.) 2020; 7:e2019EA001004. [PMID: 32715025 PMCID: PMC7375156 DOI: 10.1029/2019ea001004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
We have designed and built a versatile modularized software library-ODYN-that wraps a comprehensive set of advanced data analysis methods meant to facilitate the study of turbulence, nonlinear dynamics, and complexity in space plasmas. The Python programming language is used for the algorithmic implementation of models and methods devised to understand fundamental phenomena of space plasma physics like elements of spectral analysis, probability distribution functions and their moments, multifractal analysis, or information theory. ODYN is an open-source software analysis tool and freely available to any user interested in turbulence and nonlinear dynamics analysis and provides a tool to perform automatic analysis on large collections of space measurements, in situ or simulations, a feature that distinguishes ODYN from other similar software. A user-friendly configurator is provided, which allows customization of key parameters of the analysis methods, most useful for nonprogrammers.
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Affiliation(s)
| | - M.M. Echim
- Institute of Space Science (ISS)MăgureleRomania
- The Royal Belgian Institute for Space Aeronomy (BIRA‐IASB)BrusselsBelgium
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Meyrand R, Kanekar A, Dorland W, Schekochihin AA. Fluidization of collisionless plasma turbulence. Proc Natl Acad Sci U S A 2019; 116:1185-1194. [PMID: 30610178 PMCID: PMC6347695 DOI: 10.1073/pnas.1813913116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In a collisionless, magnetized plasma, particles may stream freely along magnetic field lines, leading to "phase mixing" of their distribution function and consequently, to smoothing out of any "compressive" fluctuations (of density, pressure, etc.). This rapid mixing underlies Landau damping of these fluctuations in a quiescent plasma-one of the most fundamental physical phenomena that makes plasma different from a conventional fluid. Nevertheless, broad power law spectra of compressive fluctuations are observed in turbulent astrophysical plasmas (most vividly, in the solar wind) under conditions conducive to strong Landau damping. Elsewhere in nature, such spectra are normally associated with fluid turbulence, where energy cannot be dissipated in the inertial-scale range and is, therefore, cascaded from large scales to small. By direct numerical simulations and theoretical arguments, it is shown here that turbulence of compressive fluctuations in collisionless plasmas strongly resembles one in a collisional fluid and does have broad power law spectra. This "fluidization" of collisionless plasmas occurs, because phase mixing is strongly suppressed on average by "stochastic echoes," arising due to nonlinear advection of the particle distribution by turbulent motions. Other than resolving the long-standing puzzle of observed compressive fluctuations in the solar wind, our results suggest a conceptual shift for understanding kinetic plasma turbulence generally: rather than being a system where Landau damping plays the role of dissipation, a collisionless plasma is effectively dissipationless, except at very small scales. The universality of "fluid" turbulence physics is thus reaffirmed even for a kinetic, collisionless system.
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Affiliation(s)
- Romain Meyrand
- Laboratoire de Physique des Plasmas, École Polytechnique, F-91128 Palaiseau Cedex, France;
- Space Sciences Laboratory, University of California, Berkeley, CA 94720
| | - Anjor Kanekar
- Department of Physics, University of Maryland, College Park, MD 20742-3511
- Palantir Technologies, London W1D 3QW, United Kingdom
| | - William Dorland
- Department of Physics, University of Maryland, College Park, MD 20742-3511
- Rudolf Peierls Centre for Theoretical Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Alexander A Schekochihin
- Rudolf Peierls Centre for Theoretical Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom
- Merton College, Oxford OX1 4JD, United Kingdom
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Šafránková J, Němeček Z, Němec F, Přech L, Pitňa A, Chen CHK, Zastenker GN. SOLAR WIND DENSITY SPECTRA AROUND THE ION SPECTRAL BREAK. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/803/2/107] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Chen CHK, Salem CS, Bonnell JW, Mozer FS, Bale SD. Density fluctuation spectrum of solar wind turbulence between ion and electron scales. PHYSICAL REVIEW LETTERS 2012; 109:035001. [PMID: 22861861 DOI: 10.1103/physrevlett.109.035001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Indexed: 06/01/2023]
Abstract
We present a measurement of the spectral index of density fluctuations between ion and electron scales in solar wind turbulence using the EFI instrument on the ARTEMIS spacecraft. The mean spectral index at 1 AU was found to be -2.75±0.06, steeper than predictions for pure whistler or kinetic Alfvén wave turbulence but consistent with previous magnetic field measurements. The steep spectra are also consistent with expectations of increased intermittency or damping of some of the turbulent energy over this range of scales. Neither the spectral index nor the flattening of the density spectra before ion scales were found to depend on the proximity to the pressure anisotropy instability thresholds, suggesting that they are features inherent to the turbulent cascade.
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Affiliation(s)
- C H K Chen
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA.
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Hnat B, Chapman SC, Gogoberidze G, Wicks RT. Scale-free texture of the fast solar wind. Phys Rev E 2012; 84:065401. [PMID: 22304144 DOI: 10.1103/physreve.84.065401] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 11/22/2011] [Indexed: 11/07/2022]
Abstract
The higher-order statistics of magnetic field magnitude fluctuations in the fast quiet solar wind are quantified systematically, scale by scale. We find a single global non-Gaussian scale-free behavior from minutes to over 5 h. This spans the signature of an inertial range of magnetohydrodynamic turbulence and a ~1/f range in magnetic field components. This global scaling in field magnitude fluctuations is an intrinsic component of the underlying texture of the solar wind and puts a strong constraint on any theory of solar corona and the heliosphere. Intriguingly, the magnetic field and velocity components show scale-dependent dynamic alignment outside of the inertial range.
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Affiliation(s)
- B Hnat
- Centre for Fusion, Space and Astrophysics, Physics Department, University of Warwick, Coventry, United Kingdom
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Chapman SC, Nicol RM. Generalized similarity in finite range solar wind magnetohydrodynamic turbulence. PHYSICAL REVIEW LETTERS 2009; 103:241101. [PMID: 20366193 DOI: 10.1103/physrevlett.103.241101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Indexed: 05/29/2023]
Abstract
Extended or generalized similarity is a ubiquitous but not well understood feature of turbulence that is realized over a finite range of scales. The ULYSSES spacecraft solar polar passes at solar minimum provide in situ observations of evolving anisotropic magnetohydrodynamic turbulence in the solar wind under ideal conditions of fast quiet flow. We find a single generalized scaling function characterizes this finite range turbulence and is insensitive to plasma conditions. The recent unusually inactive solar minimum--with turbulent fluctuations down by a factor of approximately 2 in power--provides a test of this invariance.
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Affiliation(s)
- S C Chapman
- Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom.
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Kiyani KH, Chapman SC, Khotyaintsev YV, Dunlop MW, Sahraoui F. Global scale-invariant dissipation in collisionless plasma turbulence. PHYSICAL REVIEW LETTERS 2009; 103:075006. [PMID: 19792654 DOI: 10.1103/physrevlett.103.075006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Indexed: 05/28/2023]
Abstract
A higher-order multiscale analysis of the dissipation range of collisionless plasma turbulence is presented using in situ high-frequency magnetic field measurements from the Cluster spacecraft in a stationary interval of fast ambient solar wind. The observations, spanning five decades in temporal scales, show a crossover from multifractal intermittent turbulence in the inertial range to non-Gaussian monoscaling in the dissipation range. This presents a strong observational constraint on theories of dissipation mechanisms in turbulent collisionless plasmas.
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Affiliation(s)
- K H Kiyani
- Centre for Fusion, Space and Astrophysics; University of Warwick, Coventry CV4 7AL, United Kingdom.
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