Arctic Nutrient StreamsChris, Oliver, Steph, Mick

NSIDC greatly simplified cartoon of Arctic through-flow. On time scales of 7-10 years ~1Sv of Pacific water migrates to the sub-Arctic Atlantic. This may provide a pathway for nutrients (esp. Si).

Cross-polar tracer flow

Tracer concentration at different depths v time for dye initially injected south of Bering Strait into cs510 Arctic cut-out.

Movie ends before tracer reaches Labrador and Greenland Seas. Takes ~5-10 years to transit.

Global nutrient budgetsGanachaud and Wunsch used WOCE and other cruise data in inverse estimate of nutrient fluxes.

southward

northward

Can we see an appropriate Pac Atl silica flux?

Testing in Arctic simulation

Pathways are clearly seen. Shallow, silica rich water enters from Pacific and moves to Atlantic – deepening as it goes.

Do budgets look plausible?

Budgets across sections – organic+inorganic

Denmark Strait -41kmol/sCAA -11kmol/s Iceland basin 14kmol/s

Bering 38kmol/s

Inorganic part

Denmark Strait -38kmol/s Iceland basin 13kmol/sCAA -11kmol/s

Bering +28kmol/s

Summary

• Along with riverine input Pacific water through flow is a supplier of North Atlantic silica.

• Transports in simulations are within estimated total transports.