The Role of Intermittency in Anisotropic Plasma Velocity Distributions

Turbulence in the solar wind spans several decades in frequency/wavenumber. The self-similar energy exchange between subsequent scales develops a universal power-law scaling ($k^{-5/3}$). In the solar wind, magnetic structures, like current sheets, disrupt the smooth flow of energy resulting in an intermittent signal. Periods of enhanced intermittency are associated with higher spectral indices. Near ion scales, intermittency increases, developing the dissipation range, where kinetic effects become important. Understanding the behavior of the solar wind turbulence at these scales requires knowledge of the ion velocity distribution. We first characterize the intermittency of periods using the Partial Variance of Increments (PVI). Next, we examine the ion velocity distribution function (VDF) from spacecraft measurements using a Hermite Decomposition (HD) technique. Using both PVI and HD, we correlate the amplitude of various Hermite modes of ion VDFs with intermittency in solar wind turbulence.