Magnetic field rotations in the solar wind at kinetic scales

The solar wind magnetic field contains rotations at a broad range of scales, which have been extensively studied in the magnetohydrodynamics range. Here, we present an extension of this analysis to the range between ion and electron kinetic scales. The distribution of rotation angles was found to be approximately lognormal, shifting to smaller angles at smaller scales almost self-similarly, but with small, statistically significant changes of shape. The fraction of energy in fluctuations with angles larger than alpha was found to drop approximately exponentially with alpha, with e-folding angle 9.8A degrees at ion scales and 0.66A degrees at electron scales, showing that large angles (alpha A > 30A degrees) do not contain a significant amount of energy at kinetic scales. Implications for kinetic turbulence theory and the dissipation of solar wind turbulence are discussed.