Abstract We report observations of solar wind turbulence derived from measurements by the Parker Solar Probe. Our findings reveal the emergence of finite magnetic helicity within the transition range of the turbulence, aligning with signatures of kinetic Alfvén waves (KAWs). Notably, as the wave scale transitions from superion to subion scales, the ratio between KAWs with opposite signs of magnetic helicity initially increases from approximately one to 6.5, before decreasing back to one. This observation provides, for the first time, compelling evidence for the transition from imbalanced to balanced kinetic Alfvénic turbulence.
Zhao et al. (Fri,) studied this question.