The delivery of nutrients to the sunlit surface ocean spurs phytoplankton growth and the production of particulate organic carbon (POC). As organisms die or are consumed and excreted, some of these particles settle and are exported deep into the ocean interior before remineralization occurs; this process is a component of what is commonly called the “biological pump” (see Ducklow et al., this issue). Equations that generalize the relationship between the amount of carbon produced and the amount exported from the surface ocean, as well as the relationship between the export flux and ocean depth, are key components of models that seek to predict the distribution of CO2 in the ocean in time and space.

Berelson, W.M. 2001. The flux of particulate organic carbon into the ocean interior: A comparison of four U.S. JGOFS regional studies. Oceanography 14(4):59–67, https://doi.org/10.5670/oceanog.2001.07.

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