Probability Distribution Functions of Field Variations, Non-Gaussianity and Intermittency in the Turbulent Solar Wind

Helio Research, La Crescenta CA

Investigators

Abstract

The proposer plans to study solar wind turbulence by applying statistical analysis techniques to ACE, Wind, and Helios 2 spacecraft data. Specifically, she will analyze magnetic field probability distribution functions (PDFs) in order to seek the causes of intermittency and the departures of solar wind plasma structures from Gaussian profiles. She expects to determine whether phase correlation or spectral variability is the main cause of observed non-Gaussian PDFs of magnetic field variations. In this investigation, she will extend her prior calculations and modeling of non-Gaussian PDFs to a broader range of solar wind parameters, testing both random-phase and phase-correlated models. The proposer will thereby produce theoretical predictions of these PDFs, from the largest to the smallest separation scales, and provide definitive tests of the relative impacts of variability and phase correlations on the non-Gaussian nature of such probability distribution functions. The proposer explains that her new model of intermittent turbulence will be valuable for estimating the scattering of solar wind energetic particles and for quantifying the dispersal of solar wind magnetic field lines. She notes that such information is crucial to accurate space weather predictions of solar energetic particle intensities at the Earth. As a female scientist, the proposer is a member of an underrepresented group in solar physics. Therefore, funding this research will contribute to broadening diversity in the field.