Subsurface structural changes associated with successive 11-yr solar activity cycles have been progressively more confined near the surface: new helioseismic results on Cycles 22–25 from BiSON. - Chaplin, William J; Basu, Sarbani; Howe, Rachel; Elsworth, Yvonne; Hale, Steven J; Murray, Eleanor (Monthly Notices of the Royal Astronomical Society, 2026)