Cross Helicity Correlations in the Solar Wind

Over the last decade, several magnetohydrodynamic models of the solar wind proposed a two component structure for the fluctuations: a "slab" (Alfvénic) component with wavenumbers parallel to the ambient dc magnetic field and a quasi two-dimensional (turbulent) component with wavenumbers mo...

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Autores principales: Dasso, S., Milano, L.J., Matthaeus, W.H., Smith, C.W., Velli M., Bruno R., Malara F.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0094243X_v679_n_p546_Dasso
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spelling todo:paper_0094243X_v679_n_p546_Dasso2023-10-03T14:56:07Z Cross Helicity Correlations in the Solar Wind Dasso, S. Milano, L.J. Matthaeus, W.H. Smith, C.W. Velli M. Bruno R. Malara F. Magnetohydrodynamics Cross correlations Cross-correlation function DC magnetic field Initial support Magnetohydrodynamic model Three-dimensional correlation Turbulent properties Two-component structures Solar wind Over the last decade, several magnetohydrodynamic models of the solar wind proposed a two component structure for the fluctuations: a "slab" (Alfvénic) component with wavenumbers parallel to the ambient dc magnetic field and a quasi two-dimensional (turbulent) component with wavenumbers mostly perpendicular to the magnetic field. Initial support and motivation for these models was given in part from the study of three dimensional correlation functions for the magnetic field from solar wind data (W.H Matthaeus, M.L. Goldstein and D.A. Roberts 1990, JGR 95, 20673). We extend here this study to the analysis of the cross-correlation between the velocity and the magnetic field. The cross-correlation function is simply related to the cross helicity power spectrum, a quantity of great interest for solar wind models. This quantity provides, on one hand, a measure of the relative importance of outgoing and incoming Alfvénic fluctuations. On the other hand, the turbulent properties of the system are greatly influenced by the amount of cross helicity present in it. We analyze ACE data and present preliminary results for the three dimensional cross-correlation function. Special emphasis is given to the implications for solar wind models. © 2003 American Institute of Physics. CONF info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0094243X_v679_n_p546_Dasso
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Magnetohydrodynamics
Cross correlations
Cross-correlation function
DC magnetic field
Initial support
Magnetohydrodynamic model
Three-dimensional correlation
Turbulent properties
Two-component structures
Solar wind
spellingShingle Magnetohydrodynamics
Cross correlations
Cross-correlation function
DC magnetic field
Initial support
Magnetohydrodynamic model
Three-dimensional correlation
Turbulent properties
Two-component structures
Solar wind
Dasso, S.
Milano, L.J.
Matthaeus, W.H.
Smith, C.W.
Velli M.
Bruno R.
Malara F.
Cross Helicity Correlations in the Solar Wind
topic_facet Magnetohydrodynamics
Cross correlations
Cross-correlation function
DC magnetic field
Initial support
Magnetohydrodynamic model
Three-dimensional correlation
Turbulent properties
Two-component structures
Solar wind
description Over the last decade, several magnetohydrodynamic models of the solar wind proposed a two component structure for the fluctuations: a "slab" (Alfvénic) component with wavenumbers parallel to the ambient dc magnetic field and a quasi two-dimensional (turbulent) component with wavenumbers mostly perpendicular to the magnetic field. Initial support and motivation for these models was given in part from the study of three dimensional correlation functions for the magnetic field from solar wind data (W.H Matthaeus, M.L. Goldstein and D.A. Roberts 1990, JGR 95, 20673). We extend here this study to the analysis of the cross-correlation between the velocity and the magnetic field. The cross-correlation function is simply related to the cross helicity power spectrum, a quantity of great interest for solar wind models. This quantity provides, on one hand, a measure of the relative importance of outgoing and incoming Alfvénic fluctuations. On the other hand, the turbulent properties of the system are greatly influenced by the amount of cross helicity present in it. We analyze ACE data and present preliminary results for the three dimensional cross-correlation function. Special emphasis is given to the implications for solar wind models. © 2003 American Institute of Physics.
format CONF
author Dasso, S.
Milano, L.J.
Matthaeus, W.H.
Smith, C.W.
Velli M.
Bruno R.
Malara F.
author_facet Dasso, S.
Milano, L.J.
Matthaeus, W.H.
Smith, C.W.
Velli M.
Bruno R.
Malara F.
author_sort Dasso, S.
title Cross Helicity Correlations in the Solar Wind
title_short Cross Helicity Correlations in the Solar Wind
title_full Cross Helicity Correlations in the Solar Wind
title_fullStr Cross Helicity Correlations in the Solar Wind
title_full_unstemmed Cross Helicity Correlations in the Solar Wind
title_sort cross helicity correlations in the solar wind
url http://hdl.handle.net/20.500.12110/paper_0094243X_v679_n_p546_Dasso
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AT smithcw crosshelicitycorrelationsinthesolarwind
AT vellim crosshelicitycorrelationsinthesolarwind
AT brunor crosshelicitycorrelationsinthesolarwind
AT malaraf crosshelicitycorrelationsinthesolarwind
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