TEX86 reconstructs past temperatures using membrane lipids (GDGTs) produced by marine archaea, whose composition changes with environmental temperature. Because these compounds are typically produced below the surface mixed layer, TEX86 often reflects shallow subsurface temperatures that closely track sea‑surface variability. MioOcean applies multiple modern calibrations, including Bayesian and machine‑learning approaches, and reports both surface and subsurface temperature estimates to account for regional and depth‑related differences in GDGT production.