Authors: Julian Toczylowski (Andrews University), Jay Johnson (Andrews University), Simon Wing (Johns Hopkins University), and Thierry Dudok de Wit (ISSI)

To better understand the dynamics of the solar cycle, we analyze sunspot area data (http://solarcyclescience.com/AR_Database/bflydata.txt) organized by Carrington rotation, focusing on latitudinal and interhemispheric interactions over 14 solar cycles (1874 to 2024). We use information theoretic measures, mutual information (MI) and transfer entropy (TE), to establish nonlinear correlations and to quantify directional information flow between high- and low-latitude temporal modes across and between hemispheres. Our results reveal a helical TE structure near 15° latitude reflecting an evolution of the intrahemispheric coupling. Additionally, TE shows that apparent low-latitude interhemispheric coupling is substantially mediated through polar field modes, consistent with Babcock-Leighton flux-transport dynamics. We further identify significant cross-scale information cascades, where QBO-band (1.3–2.5 year periodicity) activity predicts Schwabe-scale (2.5-10 year periodicity) variability in the opposite hemisphere. A permutation test on cycle-windowed statistics identifies ~1950 as a significant breakpoint (p<0.05) in polar directional TE, with interhemispheric polar MI dropping ~45% across the transition, providing evidence for a mid-20th century regime change in hemispheric coupling. These findings offer new constraints for solar dynamo models, and are consistent with the Glasberg cycle.