Kinetic range spectral features of cross-helicity using MMS
  We study spectral features of ion velocity and magnetic field correlations in
the solar wind and in the magnetosheath using data from the Magnetospheric
Multi-Scale (MMS) spacecraft. High resolution MMS observations enable the study
of transition of these correlations between their magnetofluid character at
larger scales into the sub-proton kinetic range, previously unstudied in
spacecraft data. Cross-helicity, angular alignment and energy partitioning is
examined over a suit- able range of scales, employing measurements based on the
Taylor frozen-in approximation as well as direct two-spacecraft correlation
measurements. The results demonstrate signatures of alignment at large scales.
As kinetic scales are approached, the alignment between v and b is destroyed by
demagnetization of protons.
