SHINE: Statistical Analysis of Magnetic Helicity of the Solar Wind Turbulence at Kinetic Scales

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The research agenda of this project directly addresses the SHINE goal of "understanding or characterizing the background solar wind and how it evolves." The outcome of the research work will advance the understanding of interplanetary turbulence at the kinetic scales. This project is expected to provide fundamental new insights in space physics regarding how collisionless dissipation of large-scale magnetohydrodynamic turbulence actually proceeds in the solar wind. The overall effort includes the participation of students from the University of New Hampshire. The research and EPO agenda of this SHINE project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research. The main goal of this 3-year SHINE project is to study the magnetic helicity associated with interplanetary turbulent fluctuations in the proton kinetic range. The magnetic helicity is a sensitive indicator of the physical processes responsible for the turbulent energy cascade. The project team will use spacecraft data from Wind to determine the statistical properties of the magnetic helicity. The distribution of the helicity with the scale convected past the spacecraft will be described by the value and position attained at the peak and also its width at half maximum. These properties will be studied as functions of the amplitude of the fluctuations, the plasma beta, and the cross-helicity. The spectral properties of the magnetic helicity will be calculated using both global and local mean magnetic fields from the same data sets. This will allow a direct comparison between the obtained statistical results of these two techniques. Three-dimensional hybrid numerical simulations with particle ions and fluid electrons will also be used to interpret the results found in each approach.