About this Research Topic
Models and simulations suggest that turbulence is characterized by a broad range of dynamical scales. Nonlinear interactions induce cross-scale transfer of energy, called the “turbulent cascade”. Nonlinear cascades result in intermittency, i.e. the production of small-scale coherent structures such as magnetic discontinuities and vorticity filaments, responsible for the bursty nature of fluctuations commonly measured by spacecraft instruments. Dissipation and acceleration processes are mostly observed to occur at those discontinuities embedded into the turbulence. Methodologies to detect such structures are being developed in order to efficiently identify the particle energization regions, with the main goal of understanding the fate of energy in space plasmas.
Recent high-resolution spacecraft observations provided new insight in the cross-scale connection of intermittent discontinuities, from proton down to electron scales. At these scales, intermittent structures such as current sheets may drive magnetic reconnection events, resulting in efficient energy conversion from fields to the particles. The interaction between charged particles and wave modes propagating in the plasma also contributes to the energy transfer and eventually to energy dissipation, within the kinetic range of space plasma turbulence, where cascades of different nature are observed.
Numerical simulations strongly support such cross-scale scenarios. Furthermore, the investigation of turbulence properties at sub-proton scales has been possible in the near-Earth environment, thanks to the Magnetospheric Multiscale (MMS) mission, that has provided high resolution measurements of electric fields, magnetic fields, and ion and electron velocity distribution functions (VDFs).
The recent launch of the Parker Solar Probe, whose data has become public recently, will advance significantly our understanding of space plasma turbulence both at large, intermediate, and small time scales in a region of the interplanetary space close to the source of solar wind plasma.
This Research Topic aims to gather research papers on pioneering observations, theories, and models that explain the physical processes responsible for the space plasma turbulence cascade and the resulting plasma heating. In particular, papers presenting general turbulence characterization and modeling (including radial evolution), wave-particle interactions, formation of magnetic structures, magnetic reconnection, propagation and acceleration of energetic particles in the solar wind and the near-Earth environment, both from observations and theoretical point of view, are particularly welcome.
Keywords: interplanetary medium, turbulence, space plasmas
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.