Jonathan Pietarila Graham

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We present direct numerical simulations and Lagrangian averaged (also known as alpha model) simulations of forced and free decaying magnetohydrodynamic turbulence in two dimensions. The statistics of sign cancellations of the current at small scales is studied using both the cancellation exponent and the fractal dimension of the structures. The alpha model(More)
We determine how the differences in the treatment of the subfilter-scale physics affect the properties of the flow for three closely related regularizations of Navier–Stokes. The consequences on the applicability of the regularizations as subgrid-scale ͑SGS͒ models are also shown by examining their effects on superfilter-scale properties. Numerical(More)
Using turbulent MHD simulations (magnetic Reynolds numbers up to ≈ 8000) and Hinode observations, we study effects of turbulence on measuring the solar magnetic field outside active regions. Firstly, from synthetic Stokes V profiles for the FeI lines at 6301 and 6302Å, we show that a peaked probability distribution function (PDF) for observationally-derived(More)
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