Small-scale anisotropy and intermittency in high and low-latitude solar wind

Abstract

We analyze low and high--latitude fast solar wind data from the Ulysses spacecraft from 1992 to 1994 using a a systematic method to analyse the anisotropic content of the magnetic field fluctuations. We investigate all available frequencies, 1-10^{-6} Hz, for both high and low--latitudes datasets and are able to quantify the relative importance of the anisotropic versus the isotropic fluctuations. We analyse, up to sixth order, longitudinal, transverse and mixed magnetic field correlations. Our results show that strongly intermittent and anisotropic events are present in the solar wind plasma at high frequencies/small scales, indicating the absence of a complete recovery of isotropy. Anisotropic scaling properties are compatible for high and low--latitude data, suggesting a universal behaviour in spite of the different rate of evolution of the fast solar wind streams in the two environments.

26 pages, 8 figures. Submitted to Astrophysical Journal

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• Persistence of small-scale anisotropy of magnetic turbulence as observed in the solar wind
• Weak Alfven-Wave Turbulence Revisited
• Anomalous scaling of a passive scalar advected by the turbulent velocity field with finite correlation time and uniaxial small-scale anisotropy
• Astrophysics in 2006
• Quantifying shear-induced wave transformations in the solar wind
• Correlation functions of small-scale fluctuations of the interplanetary magnetic field
• De-Biasing Structure Function Estimates From Sparse Time Series of the Solar Wind: A Data-Driven Approach