Events at Physics

<< Fall 2019 Spring 2020 Summer 2020 >>
Subscribe your calendar or receive email announcements of events
Astronomy Colloquium
Diffusion and dispersion in anisotropic magnetohydrodynamic turbulence
Date: Thursday, February 13th
Time: 3:30 pm - 5:00 am
Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM, Talk begins 3:45 PM
Speaker: Professor Jane Pratt, Georgia State University, Physics and Astronomy Deparment
Abstract: Diffusion and transport processes in turbulent plasmas constitute fundamental astrophysical problems; a clear understanding of these processes is needed in order to produce improved theoretical models for the diffusion and transport of energetic particles, including cosmic rays.
Magnetohydrodynamic (MHD) turbulence structured by a large-scale magnetic field is an essential aspect of interstellar or interplanetary plasmas. Here we investigate how turbulent diffusion and dispersion differ in the directions parallel and perpendicular to the magnetic field. We adopt the Lagrangian viewpoint, the natural point of view to study diffusion, and construct statistics based on the trajectories of Lagrangian tracer particles. From the motions of these tracer particles, we evaluate Lagrangian statistics for single-particle diffusion, two-particle dispersion, and velocity autocorrelations. We also demonstrate new Lagrangian statistics developed to understand anisotropic turbulent dispersion. Results will be presented from simulations with grid sizes up to 2048^3.

Host: Professor Ellen Zweibel
Add this event to your calendar