Century-scale sequestration fluxes of natural and anthropogenic carbon throughout the ocean’s water column by the three biologically-driven pumps and the solubility pump

There is general information on the fluxes of natural and anthropogenic carbon between the atmosphere, the ocean and the sediment. The literature also contains scattered information on various fluxes of carbon in the water column by the three biologically-driven pumps (biological, carbonate and microbial, called bio-pumps) and the physical solubility pump. Recent information shows that carbon storage in the ocean on climatically significant timescales (i.e. sequestration) takes place throughout the water column and not only in the deep ocean (typically > 1,000 m) as previously thought. It has also been shown that century-scale (≥100 years) sequestration fluxes of organic carbon by the biological pump throughout the water column are significantly larger than previously estimated based on the organic carbon flux reaching the deep ocean. This study combines available information from different sources to estimate current century-scale sequestration fluxes of natural and anthropogenic carbon throughout the ocean’s water column by the three bio-pumps and the solubility pump, together and separately. As well as consolidating our understanding of carbon fluxes in the ocean, these values provide a baseline to assess ocean management proposals, such as deployments of open-ocean carbon dioxide removal (mCDR) systems.