HR: 14:30h
AN: SM43B-04    [Abstracts]
TI: Intermittency, Self- Similarity and a stochastic dynamical model for Solar Wind Turbulence
AU: Rowlands, G
EM: G.Rowlands@warwick.ac.uk
AF: Space and Astrophysics, University of Warwick, Coventry, CV4 7AL United Kingdom
AU: * Chapman, S C
EM: sandrac@astro.warwick.ac.uk
AF: Space and Astrophysics, University of Warwick, Coventry, CV4 7AL United Kingdom
AU: Hnat, B
EM: hnat@astro.warwick.ac.uk
AF: Space and Astrophysics, University of Warwick, Coventry, CV4 7AL United Kingdom
AB: The solar wind provides a natural laboratory for observations of MHD turbulence over extended temporal scales. We identify approximate self-similarity in the Probability Density Functions (PDF) of fluctuations in certain solar wind in- situ bulk plasma parameters. Whereas the fluctuations of speed for example are multi-fractal, we find that under certain conditions the fluctuations in the ion density, field and particle energy densities and MHD-approximated Poynting flux are approximately self-similar on timescales up to tens of hours. The intermittency of thesystem is then expressed in these parameters through the non-Gaussian nature of the single curve that describes the fluctuations PDF up to this timescale. Self- similarity implies that a simple Fokker-Planck model exists for the timeseries and we derive this here along with the associated Langevin equation- a stochastic dynamical equation for the fluctuations in the timeseries. This is an example of a generic approach to turbulence, with connections with our understanding of the statistical mechanics of correlated systems generally.
DE: 2149 MHD waves and turbulence
DE: 2159 Plasma waves and turbulence
DE: 3210 Modeling
DE: 3250 Fractals and multifractals
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting