2604.00684 CUSUM Change-Point Detection in Solar Cycle Asymmetry: Evidence for a Structural Transition in the Early Nineteenth Century
The temporal asymmetry of the solar activity cycle—characterized by a faster rise to maximum than decline to minimum—is a well-established feature of solar variability, closely linked to the Waldmeier effect. Here we apply cumulative sum (CUSUM) change-point analysis to the rise-fall asymmetry ratio across all 24 complete solar cycles (1755–2024) using the SILSO v2.