Biology, physics and gravity interact to pump organic carbon into the deep sea. The processes of fixation of inorganic carbon in organic matter during photosynthesis, its transformation by foodweb processes (trophodynamics), physical mixing, transport and gravitational settling are referred to collectively as the “biological pump” (Figure 1). When the Global Ocean Flux Study (GOFS) began in 1984 in the U.S., followed in 1987 by the international Joint Global Ocean Flux Study (JGOFS), several ideas about the functioning of the biological pump formed the conceptual core of the fledgling program:
- The biological and physical processes in the ocean that control the air-sea carbon dioxide (CO2) balance are key factors In the planetary climate system.
- The efficiency of the biological pump, expressed as the amount of carbon exported from the surface layer divided by the total amount produced through photosynthesis, is determined by foodweb processes.
- Pump efficiency and export processes can be monitored and understood through a global network of sediment traps and satellite sensors, informed by process studies and models.