Analysis and visualization of small-scale structures occurring in high-resolution MHD simulation

We present methods of combining quantitative and visualization techniques to identify and analyze structures, such as folds and current sheets, resulting from three-dimensional MHD flow simulation. These methods have been applied to the results of direct numerical simulations with grids up to 15363 points. A desktop suite of analysis and visualization tools ("Vapor") has been developed at NCAR for interactive analysis of huge datasets. Simulation data on very large grids are analyzed and visualized directly from a wavelet representation, enabling interactive isolation of current sheets and vortices, and analysis of their time-evolution. Flow integration and volume rendering are applied to local regions in the grid, combined with numerical analysis to characterize geometric structures that result. These techniques enabled the discovery of parallel current and vorticity sheets, found to form at the same spatial locations, and the sheets were seen to further destabilize and fold or roll-up after an initial exponential phase. A self-similar evolution of the current and vorticity maxima was also identified and characterized using these methods.