Speaker
Dr
Marius Echim
(IASB)
Description
In-situ measurements of magnetic field fluctuations in the terrestrial magnetosheath revealed differences between the quasi-perpendicular and quasi-parallel shock geometry. In the quasi-parallel case the fluctuations are strongly intermittent as suggested by the scale dependent non-Gaussian wings of the probability distribution functions (PDFs) and the scale dependent behaviour of their fourth order moment. Further insight on the structure of fluctuations and their scale behavior is provided by the multirfractal analysis. The Rank Ordered Multifractal Analysis (ROMA) invented by Wu and Chang (Phys Rev E, 2008) is capable of disentangling the ranges of fluctuations that exhibit the same fractal (self-similar) dimension in terms of the local invariant property based on the scaled amplitude of fluctuations. It can thereby identify the different regimes of fluctuations (e.g., persistency, antipersistency) and different physical regimes (e.g., kinetic/MHD). A ROMA analysis of the intermittent turbulence in the magnetosheath describing the multiscale and dissipation behaviour over ranges of scales, in the coarse-grained sense, will be presented and provides a coplex view of developping turbulence in the terrestrial magnetosheath.
Primary author
Dr
Marius Echim
(IASB)
