Authors: Gregory G. Howes (University of Iowa)

The evolution of heliospheric plasmas is strongly influenced by kinetic plasma physics processes that govern the flow of energy from the Sun, through the solar wind, to the planetary magnetospheres, and further on to the outer boundary of the heliosphere with the local interstellar medium. Fundamental kinetic plasma physics phenomena—such as turbulence, magnetic reconnection, collisionless shocks, and kinetic instabilities—control the energization of particles, either through heating of the plasma species or the acceleration of a small fraction of particles to high energy. These fundamental mechanisms mediate the impact of extreme space weather events on the technological infrastructure upon which our daily lives depend, such as communication and GPS navigation satellites and the electrical power grid. Yet, despite the ability to measure directly with spacecraft the evolution of the particles and electromagnetic fields in space, our detailed knowledge of how turbulence, reconnection, shocks, and instabilities actually control particle energization remains incomplete. The recent development of innovative velocity-space diagnostics that resolve the energization of particles as a function of their position in three-dimensional velocity space has opened up a new avenue for the identification of proposed kinetic particle energization mechanisms and the quantification of the resulting energization rate using single-point spacecraft measurements. In this plenary talk, I will briefly review the kinetic theory underlying two of these techniques: the field-particle correlation technique and kinetic pressure strain. I will present examples of how the application of these techniques illuminates the mechanisms governing plasma heating and particle acceleration in space plasmas and provides a framework for the development of a predictive capability for the partitioning of dissipated energy among the plasma species.