Towards a better understanding of the nutrient cycles in the ‘new’ Arctic Ocean and implications for future primary productivity and carbon export
Acronym
nuArctic
Name
Towards a better understanding of the nutrient cycles in the ‘new’ Arctic Ocean and implications for future primary productivity and carbon export
Description
The Arctic is warming more than twice as fast as temperate regions due to anthropogenic Climate Change, and summer sea-ice is expected to vanish by the middle of the century. In this context, we hypothesize that Arctic marine primary productivity will increase due to sea-ice loss until the limitation of nutrients (nitrate in particular) outweighs the benefits of higher light availability. The available upper ocean “nutrient stocks” that get replenished in winter determine to a large extent the annual primary production. However, the quantity of nutrients remineralized in the Arctic Ocean is unknown, leading to an unbalanced budget - i.e. a ‘missing source’ of nitrate remains to be discovered. This glaring gap in our understanding is mainly due to the extreme scarcity of nutrient data, especially during the ‘polar night’ in winter and from the mesopelagic ‘twilight zone’ (in ~100-1000 m depth). The objective of the nuArctic project is to address this knowledge gap by testing the hypothesis that terrigenous inputs drive key feedbacks in the Arctic Ocean's carbon and nutrient cycles—primarily through the remineralization of organic matter, a critical process linking surface and deep ocean layers.
nuArctic has been funded by the BMBF (project 03F0918A). Computing resources were provided by the North-German Supercomputing Alliance (HLRN) project hbk00083. This work has also received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 820989 (project COMFORT; https://comfort.w.uib.no/). COMFORT aims to assess tipping points in the coupled cycles of carbon, oxygen, and nutrients in the ocean for determining and achieving safe operating spaces.