Ocean biology needs to be included in the model to capture the biological pump, including the carbonate pump. To represent the physics of the ocean, a version of the Hadley Centre climate model HadCM3 is used. The ocean component is presently run at a horizontal resolution of 3.75 degrees longitude by 2.5 degrees latitude, compared to the version used in climate prediction which has a 1.25 degree resolution. The reduced resolution means the model represents the ocean physics less well, but it does require less computing resources and hence greater testing of the carbon cycle in the model can be performed. A schematic of how these components fit together can be seen to the right.
Phytoplankton require sunlight and nutrients to grow.
Zooplankton prey on phytoplankton and in turn are prey themselves, which is represented by a mortality loss for the zooplankton. Waste products and dead material form detritus, which breaks down back to nutrient. Further to the four biological components are two components representing carbon in the ocean. These are dissolved inorganic carbon and alkalinity. The dissolved inorganic carbon is taken up by phytoplankton growth and returned with biological breakdown.