Revisiting the Winding Angle of the Heliospheric Magnetic Field: Investigating the Influence of Turbulence

The nature, and geometry, of the heliospheric magnetic field (HMF) plays a significant role in the transport of energetic charged particles, whether these be of solar or galactic origin. The present study investigates the winding angle of the HMF by analysing almost 60 years of spacecraft data, by employing methods based on the assumption of a Parker HMF from prior studies, as well as a 3D definition of the winding angle. The 2D results reveal an overwound (relative to the expected Parker field result) winding angle with a clear solar cycle dependence, in agreement with previous studies. The 3D results, however, indicate a consistently underwound field. It is further demonstrated that this winding can potentially be explained by the meandering of HMF lines due to the presence of turbulence. Furthermore, consequences of this phenomenon for energetic particle transport, particularly for magnetic focusing, are discussed.