Abstract
Marine life plays a key role in the Earth s climate. To grow, marine algae extract almost as much carbon dioxide from the atmosphere annually as all plants on land. This primary production fuels the marine ecosystem. The resulting waste sinks, as export , sequestering large amounts of carbon at depth, away from the atmosphere. Atmospheric carbon dioxide levels can be very sensitive to small changes in the depth at which recycling (or remineralisation ) of this waste back into nutrients takes place. We have sufficient observations of sinking material to investigate the process of remineralisation but far from enough to produce a global map that could be used to test climate models. We do have such maps for nutrient distributions, that are the consequence of the remineralisation, but traditionally models take too long to run to allow such comparisons. A new technique (the Transport Matrix method) provides a means of running models much faster. In tandem with this technical development, the mechanisms controlling the process of export have become much better understood in recent years. It is timely therefore to unite these recent advances to ensure that climate models accurately capture this key process of the Earth system.
United Kingdom