Using Tracers, Atmospheric Indices and Model Output to explain changes in the Arctic Ocean Inflow and Outflow through Fram Strait.


This project will combine new and existing tracer measurements from Fram Strait to provide a continuous >32 year time series that will be used to identify processes driving variations in the Arctic Ocean inflow and outflow. The volume, characteristics and sources of water masses entering and exiting the Arctic Ocean vary in time and are expected to change under a declining sea-ice cover, influencing the physical environment and Arctic ecosystem.
Several hypotheses suggest how variations in the large scale atmospheric circulation over the Arctic might influence the transport, sources and pathways of surface freshwater, and warm Atlantic water passing though Fram Strait. We want to test those hypotheses by comparing established atmospheric indices with the time series of hydrographic, current and tracer observations in Fram Strait. We will evaluate the consequences for the amount of freshwater, Atlantic water and carbon transported, as well as the effect on the ocean acidification state.
To better understand the mechanisms by which the atmosphere, declining sea-ice cover and the Arctic Ocean's response influence the freshwater outflow we will compare our time series of observations with simulated tracers in the low-resolution model NAOSIM (1948-present) and identify low-frequency processes that affect pathways of water exported though Fram Strait. The higher-resolution Fram Centre coupled model (1993-2010) will be used to investigate the effect of eddies on pathways and time scales of Arctic and Atlantic water transport. The proposed project will allow us to identify important processes affecting Arctic Ocean circulation and deliver essential new knowledge that will improve ocean and sea-ice predictions.

The project is funded by the Norwegian FRAM centre as part of the FRAM flagship "Arctic Ocean". It is led by Paul Dodd from the NPI (Norwegian Polar Institute).