Fig. 4: Temporal evolution of sea surface salinity (SSS) and δ¹⁸O_sw in CTR and perturbing experiments.

| A scatter plot of SSS and δ¹⁸O_sw of ocean grid points over 90°S-70°S at the surface level is presented with ellipses providing probabilistic representations. The grey ellipses illustrate the 1 to 4σ probabilistic area of SSS and δ¹⁸O_sw in the control experiment during 2001–2100 (n = 81400), centered on the black-squared mark representing the averaged values. The top and right-hand side panels show probabilistic density functions of SSS and δ¹⁸O_sw, respectively. Colored ellipses present 1σ probabilistic areas for ten years (n = 8140) in each sequential 10-year interval from phase 1 to phase 5. Phases 1 through 5 are calculated at 10-year intervals, beginning in 2006 CE and continuing every decade thereafter. Consequently, phase 1 represents the period from 2006 to 2015 CE, roughly corresponding to the year 2010 CE. The phases 1, 2, 3, 4, and 5 corresponds to the years 2010, 2020, 2030, 2040, and 2050 CE, respectively. Colored ellipses highlight responses from the combined climate and source effects (red, FWF-GHG585) and climate effects only (green, FWF0-GHG585). Mean SSS and δ¹⁸O_sw values in the five sequential time phases are denoted by colored square marks.