1. A prospectus on kinetic heliophysics
- Author
-
Gregory G. Howes
- Subjects
Physics ,Field (physics) ,Turbulence ,FOS: Physical sciences ,Magnetic reconnection ,Plasma ,Condensed Matter Physics ,Kinetic energy ,01 natural sciences ,Space Physics (physics.space-ph) ,Physics - Plasma Physics ,Computational physics ,Plasma Physics (physics.plasm-ph) ,Particle acceleration ,Heliophysics ,Astrophysics - Solar and Stellar Astrophysics ,Physics - Space Physics ,13. Climate action ,INVITED PAPERS ,Physics::Space Physics ,0103 physical sciences ,010306 general physics ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Heliosphere - Abstract
Under the low density and high temperature conditions typical of heliospheric plasmas, the macroscopic evolution of the heliosphere is strongly affected by the kinetic plasma physics governing fundamental microphysical mechanisms. Kinetic turbulence, collision less magnetic reconnection, particle acceleration, and kinetic instabilities are four poorly understood, grand-challenge problems that lie at the new frontier of kinetic heliophysics. The increasing availability of high cadence and high phase-space resolution measurements of particle velocity distributions by current and upcoming spacecraft missions and of massively parallel nonlinear kinetic simulations of weakly collisional heliospheric plasmas provides the opportunity to transform our understanding of these kinetic mechanisms through the full utilization of the information contained in the particle velocity distributions. Several major considerations for future investigations of kinetic heliophysics are examined. Turbulent dissipation followed by particle heating is highlighted as an inherently two-step process in weakly collisional plasmas, distinct from the more familiar case in fluid theory. Concerted efforts must be made to tackle the big-data challenge of visualizing the high-dimensional (3D-3V) phase space of kinetic plasma theory through physics-based reductions. Furthermore, the development of innovative analysis methods that utilize full velocity-space measurements, such as the field-particle correlation technique, will enable us to gain deeper insight into these four grand-challenge problems of kinetic heliophysics. A systems approach to tackle the multi-scale problem of heliophysics through a rigorous connection between the kinetic physics at microscales and the self-consistent evolution of the heliosphere at macro scales will propel the field of kinetic heliophysics into the future., Ronald C. Davidson Award paper, 13 pages, 1 figure, in press with Physics of Plasmas
- Published
- 2017