Ulysses Ulysses paper


Structure function measurements of the intermittent MHD turbulent cascade
T. S. Horbury and A. Balogh

Nonlinear Processes in Geophysics, 4, 185 - 199, 1997

Abstract:
The intermittent nature of turbulence within solar wind plasma has been demonstrated by several studies of spacecraft data. Using magnetic field data taken in high speed flows at high heliographic latitudes by the Ulysses probe, the character of fluctuations within the inertial range is discussed. Structure functions are used extensively. A simple consideration of errors associated with calculations of high moment structure functions is shown to be useful as a practical estimate of the reliability of such calculations. For data sets of around 300 000 points, structure functions of moments above 5 are rarely reliable on the basis of this test, highlighting the importance of considering uncertainties in such calculations. When unreliable results are excluded, it is shown that inertial range polar fluctuations are well described by a multifractal model of turbulent energy transfer. Detailed consideration of the scaling of high order structure functions suggests energy transfer consistent with a "Kolmogorov" cascade.

For preprints of this paper, please contact us.


Ulysses home | Publication list
Last changed 8th May 1998 by Tim Horbury.