A grand challenge problem at the forefront of heliophysics is to understand how the energy of turbulent plasma flows and electromagnetic fields is converted into energy of the plasma particles, either…

This is a $210,789.75 grant award from the National Aeronautics and Space Administration (NASA) to the University of Iowa, a top public research university, to conduct a coordinated research effort to understand how energy is transferred from turbulent plasma flows to plasma particles in heliophysics applications. The research will utilize analytical theory, numerical simulations, and analysis of data from NASA's ARTEMIS, Magnetospheric Multiscale (MMS), and MAVEN spacecraft to develop the field-particle correlation technique as a new method for diagnosing plasma heating and particle energization resulting from the dissipation of plasma turbulence. This effort directly addresses a high-level science goal of NASA's 2013 Heliophysics Decadal Survey. There is no set-aside designation for this grant, which runs from June 2018 to November 2021.

A grand challenge problem at the forefront of heliophysics is to understand how the energy of turbulent plasma flows and electromagnetic fields is converted into energy of the plasma particles, either as heat or some other form of particle energization. Under the typically low-density and high-temperature conditions of turbulent plasmas in the heliosphere and planetary magnetospheres, the turbulent dynamics is weakly collisional, requiring the application of six-dimensional (3D-3V) kinetic plasma theory to follow the evolution of the turbulence, where energy is removed from the turbulent fluctuations by collisionless interactions between the electromagnetic fields and the individual plasma particles. The PI has recently devised the field-particle correlation technique, an innovative new method for understanding the energization of particles due to these collisionless interactions using correlations between the electromagnetic field and particle velocity distribution measurements. Here we propose a coordinated effort of analytical theory in kinetic plasma physics, nonlinear kinetic numerical simulations, and analysis of artemis, magnetospheric multiscale (MMS), and maven spacecraft observations to determine the velocity-space signatures of different particle energization mechanisms in space plasmas using the field-particle correlation technique and to use those signatures to identify the physical mechanisms governing the removal of energy from turbulent fluctuations and the consequent energization of the plasma particles. This field-particle correlation method fully utilizes single-point particle and field data from modern spacecraft instrumentation, with the potential to transform our ability to diagnose directly the plasma heating and particle energization resulting from the dissipation of plasma turbulence, thereby answering fundamental questions about the physical processes responsible for turbulent dissipation and plasma heating. This project directly addresses the high-level science goal of the 2013 NRC heliophysics decadal survey to "understand the fundamental physical processes of the space environment from the sun to earth, to other planets, and beyond to the interstellar medium."