Date: May 19, 2017
Time: 12:45 p.m.
Location: Geology 4330
Speaker: Prof. Gregory Howes, University of Iowa
Title: Understanding Turbulent Heating in Space and Astrophysical Plasmas
Abstract: The flow of energy from the sun, through interplanetary space, to the
magnetospheres of the Earth and other planets impacts the macroscopic
evolution of the heliosphere, our home in the universe. Further afield,
the evolution of many astrophysical environments is strongly influenced
by the conversion of kinetic and magnetic energy into plasma heat.
Plasma turbulence plays a key role in this process, mediating the
conversion of the energy of large-scale fields and flows to plasma heat.
But our understanding of how turbulence governs energy transport and
plasma heating remains incomplete, representing a grand challenge
problem in heliophysics. Further complicating matters is the fact that
the typically low-density and high-temperature conditions dictate that
the turbulent dynamics is weakly collisional on the length scales at
which the turbulent energy is removed, requiring the application of
kinetic plasma theory to follow the evolution and dissipation of the
turbulence. Here I will outline the frontier of efforts to understand
how kinetic turbulence in space and astrophysical plasmas leads to
plasma heating and particle energization, exploiting a combined approach
using kinetic plasma theory, supercomputer simulations, spacecraft
measurements, and even laboratory experiments.