[A-OS13] Exploring Variability and Changes in Ocean Biogeochemical Cycles

[AOS13-P11] Marine dissolved organic carbon and impact to climate change

*Jerry Tjiputra¹ (1.Norwegian Research Centre, Bjerknes Centre for Climate Research)

Keywords:Marine biogeochemical cycles, Dissolved organic carbon , Climate change projection, Earth system models

The carbon stored in the formed of dissolved organic carbon (DOC) is approximately equivalent to that in the atmospheric CO₂. Nevertheless, the role of DOC in the global carbon cycle is poorly understood and its response or potential feedback to climate change are generally overlooked. Here, four species of DOC (labile, semi-labile, semi-refractory, and refractory) are implemented in the global ocean biogeochemical model of the Norwegian Earth system model. The labile fractions are produced through phytoplankton exudation and zooplankton excretion, while the refractory fractions through remineralization processes. Temperature dependent DOC degradation based on laboratory experiments are implemented. Following several cycles of ocean overturning time scales spin-up, a quasi-equilibrium distribution of refractory DOC in the ocean interior is reached with broad agreement in amplitude and spatial patterns compared to the observations. The impact of warming-enhanced remineralization on the ocean biological carbon pump will be presented, as well as the potential feedback on long-term ocean capacity to absorb anthropogenic carbon.