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Observations of hydromagnetic turbulence in the solar windMHD turbulence is studied by analyzing magnetic field and plasma observations from Helios-1 and -2 at minimum solar activity. The steady conditions in the plasma flows and the magnetic field sector structure in 1975/1976 facilitate an investigation of the radial evolution of the turbulence from 0.29 to 1AU. In high speed streams the fluctuations in the solar wind velocity v and the magnetic field b are highly correlated (the correction coefficient almost being one), which indicates that the turbulence is mainly Alfvenic in high speed plasma. While some general fluctuation properties remain essentially unchanged from 0.29 to 1AU, power spectral analysis reveals a different frequency composition of the Alfvenic turbulence at different heliocentric distances. At 0.3AU much more 'high' frequency fluctuations contribute to the total power in the magnetic field and velocity fluctuations than at 1AU. The contributions of field magnitude fluctuations are found to be distance and frequency dependent. Magnetic field spectra with an extended frequency range up to 470Hz show certain frequency bands, where the steepness of the spectra is independent of the helicocentric distance.
Document ID
19840005006
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Denskat, K. U.
(Technische Univ. Brunswick, Germany)
Neubauer, F. M.
(Cologne Univ.)
Date Acquired
August 12, 2013
Publication Date
November 1, 1983
Publication Information
Publication: JPL Solar Wind Five
Subject Category
Solar Physics
Accession Number
84N13074
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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