Fig. 4: The ocean carbon flux and global overturning circulation before and after AMOC collapse for fully coupled version with a hosing rate of 0.2 Sv.

During the process, the changes of net and cumulative ocean carbon flux to the atmosphere under different CO₂ levels are shown in (a, b), respectively. The initial global air-sea CO₂ flux patterns at 450 ppm is shown in (c), averaged over model year 100–300. (d, e) show the difference in air-sea CO₂ flux between the average and the initial for model years 1100–1300 and 6800–7000, respectively. The positive values of CO₂ flux indicate carbon flux into the ocean and negative values represent carbon release from the ocean. The streamfunctions of global overturning circulations before and after the AMOC collapse under 450 ppm, averaged over model years 100–300 (f), 1100–1300 (g), 6800–7000 (h) are illustrated respectively.