Local anisotropy, higher order statistics, and turbulence spectra

Correlation anisotropy emerges dynamically in magnetohydrodynamics (MHD), producing stronger gradients across the large-scale mean magnetic field than along it. This occurs both globally and locally, and has significant implications in space and astrophysical plasmas, including particle scattering a...

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Autores principales: Matthaeus, W.H., Servidio, S., Dmitruk, P., Carbone, V., Oughton, S., Wan, M., Osman, K.T.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0004637X_v750_n2_p_Matthaeus
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spelling todo:paper_0004637X_v750_n2_p_Matthaeus2023-10-03T14:02:21Z Local anisotropy, higher order statistics, and turbulence spectra Matthaeus, W.H. Servidio, S. Dmitruk, P. Carbone, V. Oughton, S. Wan, M. Osman, K.T. interplanetary medium magnetic fields magnetohydrodynamics (MHD) methods: data analysis solar wind turbulence Correlation anisotropy emerges dynamically in magnetohydrodynamics (MHD), producing stronger gradients across the large-scale mean magnetic field than along it. This occurs both globally and locally, and has significant implications in space and astrophysical plasmas, including particle scattering and transport, and theories of turbulence. Properties of local correlation anisotropy are further documented here by showing through numerical experiments that the effect is intensified in more localized estimates of the mean field. The mathematical formulation of this property shows that local anisotropy mixes second-order with higher order correlations. Sensitivity of local statistical estimates to higher order correlations can be understood in connection with the stochastic coordinate system inherent in such formulations. We demonstrate this in specific cases, and illustrate the connection to higher order statistics by showing the sensitivity of local anisotropy to phase randomization, after which the global measure of anisotropy is recovered at all scales of averaging. This establishes that anisotropy of the local structure function is not a measure of anisotropy of the energy spectrum. Evidently, the local enhancement of correlation anisotropy is of substantial fundamental interest and must be understood in terms of higher order correlations, specifically fourth-order and above. © 2012. The American Astronomical Society. All rights reserved. Fil:Dmitruk, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0004637X_v750_n2_p_Matthaeus
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic interplanetary medium
magnetic fields
magnetohydrodynamics (MHD)
methods: data analysis
solar wind
turbulence
spellingShingle interplanetary medium
magnetic fields
magnetohydrodynamics (MHD)
methods: data analysis
solar wind
turbulence
Matthaeus, W.H.
Servidio, S.
Dmitruk, P.
Carbone, V.
Oughton, S.
Wan, M.
Osman, K.T.
Local anisotropy, higher order statistics, and turbulence spectra
topic_facet interplanetary medium
magnetic fields
magnetohydrodynamics (MHD)
methods: data analysis
solar wind
turbulence
description Correlation anisotropy emerges dynamically in magnetohydrodynamics (MHD), producing stronger gradients across the large-scale mean magnetic field than along it. This occurs both globally and locally, and has significant implications in space and astrophysical plasmas, including particle scattering and transport, and theories of turbulence. Properties of local correlation anisotropy are further documented here by showing through numerical experiments that the effect is intensified in more localized estimates of the mean field. The mathematical formulation of this property shows that local anisotropy mixes second-order with higher order correlations. Sensitivity of local statistical estimates to higher order correlations can be understood in connection with the stochastic coordinate system inherent in such formulations. We demonstrate this in specific cases, and illustrate the connection to higher order statistics by showing the sensitivity of local anisotropy to phase randomization, after which the global measure of anisotropy is recovered at all scales of averaging. This establishes that anisotropy of the local structure function is not a measure of anisotropy of the energy spectrum. Evidently, the local enhancement of correlation anisotropy is of substantial fundamental interest and must be understood in terms of higher order correlations, specifically fourth-order and above. © 2012. The American Astronomical Society. All rights reserved.
format JOUR
author Matthaeus, W.H.
Servidio, S.
Dmitruk, P.
Carbone, V.
Oughton, S.
Wan, M.
Osman, K.T.
author_facet Matthaeus, W.H.
Servidio, S.
Dmitruk, P.
Carbone, V.
Oughton, S.
Wan, M.
Osman, K.T.
author_sort Matthaeus, W.H.
title Local anisotropy, higher order statistics, and turbulence spectra
title_short Local anisotropy, higher order statistics, and turbulence spectra
title_full Local anisotropy, higher order statistics, and turbulence spectra
title_fullStr Local anisotropy, higher order statistics, and turbulence spectra
title_full_unstemmed Local anisotropy, higher order statistics, and turbulence spectra
title_sort local anisotropy, higher order statistics, and turbulence spectra
url http://hdl.handle.net/20.500.12110/paper_0004637X_v750_n2_p_Matthaeus
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