The simulated climate of the Last Glacial Maximum and insights into the global marine carbon cycle

摘要: Abstract. The ocean's ability to store large quantities of carbon, combined with the millennial longevity over which this reservoir is overturned, has implicated ocean as a key driver glacial–interglacial climates. However, combination processes that cause an accumulation carbon within during glacial periods still under debate. Here we present simulations Last Glacial Maximum (LGM) using CSIRO Mk3L-COAL (Carbon–Ocean–Atmosphere–Land) earth system model test contribution physical and biogeochemical storage. For LGM simulation, find significant global cooling surface (3.2 °C) expansion both minimum maximum sea ice cover broadly consistent proxy reconstructions. stores additional 267 Pg C in deep relative pre-industrial (PI) simulation due stronger Antarctic Bottom Water formation. 889 Pg C lost from upper via equilibration lower atmospheric CO2 concentration decrease export production, causing net loss PI ocean. also experiences oxygenation ( >  100 mmol O2 m−3) deepening calcite saturation horizon (exceeds bottom) at odds With modifications processes, include increased organic matter simulated release iron limitation, remineralisation decreased inorganic driven by cooler temperatures, content can be sufficiently (317 Pg C) explain reduction terrestrial (194 ± 2 330 ± 400 Pg C, respectively). Assuming LGM–PI difference 95 ppm pCO2, 55 ppm attributed biological pump, 28 ppm circulation changes remaining 12 ppm solubility. improve model–proxy agreement carbonate chemistry dissolved oxygen fields. Thus, strong evidence variations oceanic pump exert primary control on climate.