The west Antarctic Peninsula (WAP) is the fastest-warming marine environment on Earth, where rapid physical changes (sea ice decline, glacial retreat, rising ocean temperatures) are having a profound, yet complex impact on phytoplankton productivity. The overarching objective of this project is to understand the nutrient budgets and cycling underlying these biological changes, with major implications for air-sea CO2 exchange and functioning of the marine food web as the system responds to ongoing climate change. Characterising these mechanistic linkages will be key to predicting how future warming and ice losses will influence biological CO2 uptake and nutrient budgets at the WAP and larger scales, with important consequences for global biogeochemical cycles.
Variability in the polar marine nitrogen cycle will be described in detail using isotopic and biogeochemical mixing models and by constructing an isotope-constrained fixed nitrogen budget for the WAP shelf on an annual basis. These budgets will be compared to interannual changes in sea ice, water temperature and glacial inputs to elucidate the physical controls on nutrient biogeochemistry. Dynamic coupling between the nitrogen and carbon cycles, and the impact of changes in deep water behaviour on surface ocean processes will also be examined. Field campaigns are launched during austral summer 2013/14 and continue for three years, including high-resolution time-series work at Rothera Research Station (RaTS, British Antarctic Survey) and cruises in the wider WAP region (Palmer LTER, USA and BAS).
This project is supported by: