Paper#: 52
Poster #: 31
Session Name: Poster Session 1
Room: East Ballroom
Day: Tuesday
Time: 10:10 a.m.-Noon
Abstract Title: Quantifying the Multiscale Nature of Turbulent Transport in Finite Size Systems
PresentSurname: Chapman, S.C.
All Authors: S.C. Chapman, B. Hnat, J. Greenhough, G. Rowlands, N. W. Watkins
Abstract : A key issue in characterizing bursty magnetotail transport and its relationship to complex systems approaches such as turbulence and SOC is quantifying selfsimilar (scaling) behavior. One approach that has been applied to turbulent fluids (both laboratory fluid experiments and in the solar wind) is analysis of the Probability Distribution Functions (PDF) of velocity and magnetic field fluctuations in turbulent plasma flows. Here we demonstrate a model-independent method to quantify the rescaling properties of these PDFs. The technique is based on rescaling the PDF of the differenced form of the raw time series and complements fitting of the Castaing distribution. The details of the rescaled PDF, for example, the exponents of their non- Gaussian Pareto tails and how they are truncated constrains turbulence models of both open and finite sized plasma systems. The range over which scaling is identified quantifies the extent to which such systems are 'multiscale', that is, the range of physical scales over which there is strong coupling. We discuss application of the technique to in situ solar wind observations and to 'global' observables of finite sized systems where plasma transport is known to be highly irregular; such as geomagnetic indices for the earth's magnetosphere, and X ray flux from accretion disks.