Southern Ocean iron cycle provides new insight into climate change

Researchers have found that deep winter mixing, a seasonal process which carries colder and deeper, nutrient-rich water to the surface, plays very crucial role in transporting iron to the surface.

They said that the iron is then able to stimulate phytoplankton growth which supports the ocean's carbon cycle and the aquatic food chain

Researchers were also able to determine that following the winter iron surge, a recycling process is necessary to support biological activity during the spring and summer seasons.

Oceanographer, Dr Alessandro Tagliabue, from the University's School of Environmental Sciences, said that they combined all available iron data, matched them with physical data from autonomous profiling floats and used the latest satellite estimates of biological iron demand to explore how iron is supplied to the phytoplankton in the Southern Ocean.

He said that they found unique aspects to the iron cycle and how it is supplied by physical processes, making it distinct to other nutrients.

Tagliabue said that this means that the Southern Ocean's nutrient supply would be affected by changes to the climate system (such as winds and freshwater input) differently to other areas of the ocean.

Researchers have long known the region is crucial in the uptake of atmospheric CO2 and that biological processes in the Southern Ocean influence the global ocean system via northward flowing currents.