Abstract:

Anthropogenic Intensification of Surface Ocean Interannual pCO₂ Variablility

We use several global coupled atmosphere-ocean-biogeochemistry models from the Coupled Model Intercomparison Project (CMIP5) to show that the global interannual variability of the sea surface pCO₂ (calculated as 1σ) will increase by ∼64 ± 20 % by 2040-2090 relative to the beginning of the industrial revolution under the RCP8.5 scenario. All models agree that the increase in variability is a consequence of a larger background pCO2 and a lower buffering capacity that enhance the response of pCO₂ to the fluctuations of surface temperature (T) and dissolved inorganic carbon (DIC). The most skillful group of models under present‐day conditions shows a future global decrease in DIC fluctuations that will weaken the pCO₂ interannual variability (IAV). The remaining uncertainties in the projected evolution of pCO₂ variability regionally highlight the need for continuous carbon monitoring programs which will contribute to a better understanding of the oceanic carbon sink's response to increased green house emissions.

link to full paper