Nitrogen and Carbon biogeochemistry of Antarctic sea ice.
Antarctic sea ice covers up to 40 % of the Southern Ocean and is characterised by extreme changes in temperature, salinity and light. Notwithstanding the extreme conditions, the porous sea ice creates an ideal habitat for algae to thrive. It is host to large annual blooms during the austral spring with biomass concentration in the ice exceeding those observed in the underlying seawater by several orders of magnitude. Especially bottom sea ice in coastal regions (land-fast sea ice) can be considered as one of the most productive marine ecosystems worldwide. Sea ice also plays an important role in structuring the polar marine ecosystem and ice algae are pivotal in the survival of Antarctic krill. However, the nutrient dynamics that sustain this strong growth are far from being understood. Sea ice samples from several locations in Antarctica are analysed for nutrient and biomass concentrations and isotope signatures.
Antarctic land-fast sea ice (Davis Station, Scott Base, Dumont D’Urville Station)
Antarctic free drifting pack ice (East Antarctica: 63–66°S, 115–125°E).
Saroma lagoon, Sea of Okhotsk, Hokkaido, Japan
Antarctica, Sea Ice, Nitrogen cycle, Stable isotopes (15-N, 13-C, 18-O), EA-IRMS