Changing Arctic Carbon cycle in the Coastal Ocean Near-shore (CACOON): a project focussing on the dynamic interface between land and ocean in the Arctic

• Main Authors: Strauss, Jens, Mann, Paul James, Bedington, Michael, Fuchs, Matthias, Grosse, Guido, Haugk, Charlotte, Mollenhauer, Gesine, Juhls, Bennet, Ogneva, Olga, Overduin, Pier Paul, Palmtag, Juri, Polimene, Luca, Torres, Ricardo
• Format: Conference Object
• Language: unknown
• Published: 2020
• Subjects: Arctic; Arctic Ocean; Kolyma; Climate change; Ice; lena delta; permafrost; Sea ice
• Online Access: https://epic.awi.de/id/eprint/53624/; https://hdl.handle.net/10013/epic.96617878-2c9e-4605-8fc6-f86127546c6f

No other region has warmed as rapidly in the past decades as the Arctic. Funded by the British Natural Environment Research Council and the German Federal Ministry of Education and Research, the CACOON project investigates how this warming influences Arctic coastal-marine ecosystems. Arctic rivers annually carry around 13% of the globally transported dissolved organic carbon (despite the Arctic Ocean making up only approx. 1% of the Earth's ocean volume). Arctic shelf waters are therefore dominated by terrestrial carbon pools, so that shelf ecosystems are intimately linked to freshwater supplies. Arctic ecosystems also contain permafrost carbon that may be released with warming. Climate change already thaws permafrost, reduces sea-ice and increases riverine discharge, triggering important feedbacks. The importance of the near-shore region, consisting of several tightly connected ecosystems that include rivers, deltas and the shelf, is however often overlooked. Year-round studies are scarce but needed to predict the impact of shifting seasonality, fresher water, changing nutrient supply and greater proportions of permafrost-derived carbon on coastal waters. The aims of the CACOON project are to quantify the effect of changing freshwater export and permafrost thaw on the type and fate of river-borne organic matter (OM) delivered to Arctic shore, and resulting changes on ecosystem functioning in the coastal Arctic Ocean. We are achieving this through a combined observational, experimental and modelling approach. We conduct laboratory experiments to parameterise the susceptibility of terrigenous carbon to abiotic and biotic transformation and losses, then use the results from these to deliver a marine ecosystem model capable of representing major biogeochemical cycles. We apply this model to assess how future changes to freshwater runoff and carbon fluxes alter the ecosystems. To reach these aims we conducted 4 field campaigns in 2019 in the Lena and Kolyma delta region. In the Lena Delta we were using a mobile camp ...