The more motion in the ocean surface, the faster gases are exchanged. Breaking waves and bubbles allow gas molecules like CO2 to enter the water column more effectively.
Phytoplankton – the plants of our oceans. These tiny organisms need CO2 for their growth. The more phytoplankton in the ocean, the more CO2 is taken up from the atmosphere. Some species even build shells from the carbon contained in the carbon dioxide. At the end of their life cycle the shells sink down to the sea floor and thus CO2 is permanently withdrawn from the atmosphere.
In cold water gases are more soluble than in warm water. Accordingly, in cold regions more CO2 is dissolved in the water column and can be transferred to the deep ocean.