On the scaling of the dynamic alignment angle in solar wind turbulence from 0.3 to 1 au

We use Helios in-situ measurements to investigate the scaling of the angle $\theta$ between the velocity and magnetic field fluctuations, also called the scale-dependent dynamic alignment (SDDA), in solar wind turbulence and its dependency with heliocentric distance $r$, from 0.3 to 1 au. Here we analyze the SDDA as a function of the cross helicity and distance $r$, and find that the scaling of angle $\theta$ depends on both the cross helicity and the radial distance $r$. We found that intervals with lower values of normalized cross helicity (more balanced turbulence) show extended steeper scalings that cover the inertial range part of the turbulence, however, the SDDA seems to saturate (and shows a flatter behavior) already within the inertial range and then it reverses back to higher angles for smaller time scales.