Biological Carbon Pump

Biological Carbon Pump Once the solubility pump introduces carbon into surface waters, the ocean twilight zone’s biological carbon pump (BCP) plays an important role in the rapid removal of a fraction of that carbon further downward into the deep sea. The physical, chemical, and biological processes that take place in the zone start with the transport of upwards of 12 billion metric tons of carbon annually out of the surface ocean.20 Most of that carbon goes to feeding the twilight zone marine organisms, leaving roughly 10% to exit the twilight zone and reach the deep sea, effectively keeping heat-trapping GHGs out of the atmosphere. The BCP is not a single process, rather it is a collective of processes that synergistically influence the transport of carbon deep into the ocean that in turn helps regulate global climate.21 Essentially, there are three major pathways that comprise the Biological Carbon Pump (BCP): 1. Gravitational Pump, 2. Mixing Pump, and 3. Migrant Pump. (Illustration by Natalie Renier, © Woods Hole Oceanographic Institution)