Generalised Ohm’s Law in the Magnetosheath: How do plasma conditions impact turbulent electric fields?

• DOI: 10.5194/egusphere-egu23-13782
• Publication Date: 2023-02-26T04:33:27Z
• Authors: Harry Lewis; Julia Stawarz; Luca Franci; Lorenzo Matteini; Kristopher Klein; Chadi Salem
• Keywords: Magnetosheath; Ohm's law

Turbulence is a complex phenomenon whereby fluctuation energy transferred between different scale sizes as result of nonlinear interactions. Electromagnetic turbulence ubiquitous within space plasmas, wherein it associated with numerous The dynamics the magnetic field, which are widely studied in theory, intimately linked to electric controls exchange field and particles. Magnetospheric Multiscale (MMS) provides unique opportunity decompose into contributions from linear processes. evolution described by generalised Ohm’s law, breaks down components arising physical effects. Using high-resolution multipoint measurements, we compute MHD, Hall Electron Pressure terms law for 60 turbulent magnetosheath intervals. These terms, have varying function scale, arise effects related range underlying phenomena. We examine how two characteristics spectra depend on plasma conditions: transition MHD dominance (the ‘Hall scale’, kHall) relative amplitude contributions. Motivated dimensional analysis arguments appeal that can be quantified number ways MMS, demonstrate necessary refinements required reproduce measured values. scalar isotropic kinetic Alfven wave prediction ratio beta not consistent measurements. observe dominated either or dynamics, depending interval, while term only. Our work shows change conditions, may provide insight other environments.