Fig. 7: Comparison of time evoluation of Tstd and temperature gradients along the CO₂ pathway.

Time series of Tstd (black; box in Fig. 4) and temperature gradients in (a) eastern Canada and (b) northwestern Eurasia along the CO₂ pathway for each experiment (Unit: K). Black lines show Tstd for each region, and green and violet lines show dT/dy and dT/dx, respectively, with the post-stabilization period masked. The regions defining the temperature gradients are shown in Fig. 5 and their captions. This study uses three periods labeled as follows: the red lines and shading indicate the years of peak CO₂ concentration and peak period; the blue lines and shading represent the end of the ramp-down phase and early stabilization period; the yellow line and shading indicate the end of the stabilization phase and late stabilization period. The numbers in the upper corner show the correlation coefficients for the meridional (green; left) and zonal (violet; right) temperature gradients with Tstd. The results for the full integration period are presented in Fig. S7.