HR: 1340h
AN: SH23A-1144    [Abstracts]
TI: Statistical Analysis of the High-Frequency Spectral Break of the Solar Wind Turbulence at 1 AU
AU: * Markovskii, S
EM: sergei.markovskii@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
AU: Vasquez, B
EM: bernie.vasquez@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
AU: Smith, C
EM: charles.smith@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
AB: The physical mechanism responsible for the dissipation of the solar wind turbulence and the resulting plasma heating is not completely understood. To be a viable means of dissipation, any mechanism has to reproduce several observational features of the turbulence spectra. One of the important characteristics of the spectrum is its high-frequency break where the spectral slope becomes considerably steeper than the Kolmogorov-like scaling law observed in the inertial range. The onset of the spectral steepening can be inferred from the observations fairly accurately and it is a good benchmark to test various theories of the turbulence dissipation. We use a large database of magnetic field spectra and plasma parameters at 1 AU measured by the ACE spacecraft to determine the spectral break. The statistical correlation of the data points calculated according to various theoretical formulas for the break is analyzed and the least squares fits to the data are compared with the theoretically predicted scalings. We conclude that the position of the spectral break is not determined just by a scale of the turbulent fluctuations but by a combination of their scale and the amplitude at that scale. This means that the dissipation of the solar wind turbulence is an essentially nonlinear process.
DE: 2159 Plasma waves and turbulence
DE: 2164 Solar wind plasma
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting