Turbulence is a complex nonlinear dynamical behavior that we can observe in space plasmas over a wide range of temporal and spatial scales. This proposal offers to advance our understanding of plasma turbulence, a feature of nonlinear plasma electrodynamics that pervades and shapes basic physical phenomena throughout much of the universe. Much of the nonthermal energy stored by space and astrophysical plasmas is found in structures or fluctuations that are well described by magnetohydrodynamic (MHD) models. The solar corona, the solar wind, the magnetosphere, and the interstellar medium may exhibit MHD turbulence, ranging from the largest scales down to the scales at which kinetic dissipation becomes strong. Understanding this MHD turbulence is critical to problems related to coronal heating, the acceleration of the solar wind, distributed heating of the solar wind, mediation of "space weather" by transfer of energy through the heliosphere, and the transport of solar and galactic energetic charged particles throughout the solar system.
This proposal continues highly productive projects previously funded by the NSF. The PI intends to further elucidate basic properties of MHD turbulence and transport theories for macroscopic or inhomogeneous processes that include turbulence at smaller scales. He will use test particle theory and simulation to study energetic particle response to turbulence, and adopt an integrated approach using MHD and fluid simulation techniques, transport theory, analytical theories of turbulence and particle diffusion, and related analysis and interpretation of spacecraft observations. In this effort, the PI includes an educational component, supervision and mentorship of junior personnel, and potential contributions to analysis techniques, computational methods, and parallel computing strategies, as well as to industrial and cross disciplinary methodologies and applications.
