Time profiles of the solar wind turbulence parameters during the crossing of the sub-Alfvénic flow in E10. The two sub-Alfvénic solar wind intervals are indicated by the shaded areas as Figure 1. From top to bottom, the panels show the amplitude of the Elsässer variables z ^±, amplitude of the velocity fluctuations δ v and magnetic field fluctuations in Alfvén units δ b , normalized cross-helicity σ _c , normalized residual energy σ _r , the angle between the mean magnetic field and mean velocity field in the spacecraft frame ﹩{\theta }_{\mathrm{VB}}^{\mathrm{sc}}﹩, the transverse P _⊥ and longitudinal P _∥ magnetic fluctuation power, and the magnetic fluctuation power anisotropy P _⊥/P _∥.