Abstract
There are a variety of theoretical and observational indications that fluctuation energy in astrophysical and space plasma turbulence is distributed anisotropically in space relative to the magnetic field direction. The cross helicity, represented by correlations between velocity and magnetic field fluctuations, enters a magnetohydrodynamic description on equal footing with the energy, but its anisotropy has not been examined in the same degree of detail. Here we employ Advanced Coronal Explorer data to examine the rotational symmetry of the cross helicity. We find that the normalized cross helicity is associated more or less equally with all angular components of the fluctuations. This favors turbulence models that allow for cross communication between parallel and perpendicular wave numbers, suggesting that 'wavelike' and 'turbulencelike' fluctuations are strongly coupled.
Milano, L J;
Matthaeus, W H;
[1]
Dasso, S;
[2]
Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina)];
Smith, C W
[3]
- Bartol Research Institute, University of Delaware, Newark, Delaware 19716 (United States)
- Instituto de Astronomia y Fisica del Espacio (IAFE), Buenos Aires (Argentina)
- Institute for Earth, Oceans and Space, University of New Hampshire, Durham, New Hampshire 03824 (United States)
Citation Formats
Milano, L J, Matthaeus, W H, Dasso, S, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina)], and Smith, C W.
Spectral distribution of the cross helicity in the solar wind.
United States: N. p.,
2004.
Web.
doi:10.1103/PhysRevLett.93.155005.
Milano, L J, Matthaeus, W H, Dasso, S, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina)], & Smith, C W.
Spectral distribution of the cross helicity in the solar wind.
United States.
https://doi.org/10.1103/PhysRevLett.93.155005
Milano, L J, Matthaeus, W H, Dasso, S, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina)], and Smith, C W.
2004.
"Spectral distribution of the cross helicity in the solar wind."
United States.
https://doi.org/10.1103/PhysRevLett.93.155005.
@misc{etde_20617590,
title = {Spectral distribution of the cross helicity in the solar wind}
author = {Milano, L J, Matthaeus, W H, Dasso, S, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina)], and Smith, C W}
abstractNote = {There are a variety of theoretical and observational indications that fluctuation energy in astrophysical and space plasma turbulence is distributed anisotropically in space relative to the magnetic field direction. The cross helicity, represented by correlations between velocity and magnetic field fluctuations, enters a magnetohydrodynamic description on equal footing with the energy, but its anisotropy has not been examined in the same degree of detail. Here we employ Advanced Coronal Explorer data to examine the rotational symmetry of the cross helicity. We find that the normalized cross helicity is associated more or less equally with all angular components of the fluctuations. This favors turbulence models that allow for cross communication between parallel and perpendicular wave numbers, suggesting that 'wavelike' and 'turbulencelike' fluctuations are strongly coupled.}
doi = {10.1103/PhysRevLett.93.155005}
journal = []
issue = {15}
volume = {93}
journal type = {AC}
place = {United States}
year = {2004}
month = {Oct}
}
title = {Spectral distribution of the cross helicity in the solar wind}
author = {Milano, L J, Matthaeus, W H, Dasso, S, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina)], and Smith, C W}
abstractNote = {There are a variety of theoretical and observational indications that fluctuation energy in astrophysical and space plasma turbulence is distributed anisotropically in space relative to the magnetic field direction. The cross helicity, represented by correlations between velocity and magnetic field fluctuations, enters a magnetohydrodynamic description on equal footing with the energy, but its anisotropy has not been examined in the same degree of detail. Here we employ Advanced Coronal Explorer data to examine the rotational symmetry of the cross helicity. We find that the normalized cross helicity is associated more or less equally with all angular components of the fluctuations. This favors turbulence models that allow for cross communication between parallel and perpendicular wave numbers, suggesting that 'wavelike' and 'turbulencelike' fluctuations are strongly coupled.}
doi = {10.1103/PhysRevLett.93.155005}
journal = []
issue = {15}
volume = {93}
journal type = {AC}
place = {United States}
year = {2004}
month = {Oct}
}