Near-Sun Switchbacks Show Statistical Signatures of Solar Activity

Abstract: The large amplitude, Alfvénic deflections in the solar wind, called magnetic switchbacks, are a ubiquitous feature of the inner heliosphere, yet their origin and variability remain poorly understood. We investigate the dependence of large amplitude magnetic fluctuations in the inner heliosphere on both heliocentric distance and global solar activity. Using Parker Solar Probe observations, we quantify switchback deflections through their normalised deflection angle $z$. We examine both their distribution and the probability of large events, combining radial binning, sunspot-number-based activity classification, and regression analysis. We find a statistically significant but weak dependence of switchback properties on solar activity, with a decrease in large deflections at higher activity levels, alongside a modest increase with heliocentric distance. The weak activity trend suggests that multiple processes act simultaneously. Solar-cycle variations in coronal magnetic topology may modulate switchback generation at the source, while nonlinear in situ effects in the solar wind may partially evolve these signatures. Our results indicate that switchbacks retain only a limited imprint of solar activity, reflecting a coupled interplay between coronal origin and in situ evolution. This study provides a quantitative framework to disentangle activity and radial effects, and highlights the need for multi-parameter and multi-spacecraft analyses to fully understand the origin and evolution of switchbacks.