Fig. 1.

Time-dependent results of scenario #1, a net aerobic remineralization of organic matter leading to a negative δ¹³C isotopic excursion. Time advances from left to right. (A) Prescribed carbon fluxes; the only flux prescribed to change in this scenario is the decreasing oxygenic production F_prod forcing the isotopic signal. (*) Anaerobic remineralization fluxes are plotted shifted and are identically zero in this scenario. (B) Dissolved organic and inorganic carbon masses (solid lines) and δ¹³C isotopic compositions (dashed). (C) Atmospheric pCO₂ (ppm) showing a large increase, due to the increase in dissolved inorganic carbon concentration, and a decrease in ocean pH.