The Solubility Pump Assignment: Create a Quiz!

CO₂ and heat are continually exchanged between the atmosphere and the ocean. When cold dry air passes over a warmer ocean, the ocean loses heat to the atmosphere. As it gives up heat to the air, the surface ocean cools. Cooling waters are able to absorb more CO₂ from the atmosphere.

As it cools further, the surface ocean water becomes denser and denser. Once it reaches the far North Atlantic, near Greenland, for example, it becomes so dense that it finally sinks into the deep interior ocean.

Once it's down there it can be locked in the deep ocean for thousands of years, depending on the path it takes. Masses of deep water are moved around the oceans by currents.

Carbon dioxide that has been transferred to the deep ocean in the North Atlantic finds its way through to the South Atlantic, into the Indian Ocean, into the Southern Ocean and then into the Pacific Ocean. Eventually it will return to the surface in places where there is an upwelling.

An upwelling is a process in which deeper cold water rises toward the surface. It occurs in places where wind blowing across the ocean’s surface pushes water away, from continents, for example, making room for deeper waters to rise up and replace the water that was pushed out.

When that deep ocean water eventually works its way back to the surface it is again warmed by the sun, and the solubility of the CO₂ in the water decreases. Then the CO₂ gas is driven to leave the water and go into the atmosphere where CO₂ concentrations are lower than in the upwelled water.

So, that's one of the ways carbon is transferred through the global ocean. It is called the solubility pump.