Water Mass Formation, Renewal and Exchange in the Arctic Ocean: Tritium/He, 180 and 14C Measurements on the Arctic 1991 Expedition

This project is an investigation into the circulation of the deep basins of the Arctic Ocean using chemical tracers supported by closely spaced hydrographic sections. Oceanic tracers are extremely useful in assessing how the large- scale circulation maintains the hydrographic structure and the arctic sea ice cover, and in estimating the exchange of water between the Arctic Ocean and its marginal seas. This project will collect, measure, and evaluate the tritium, helium isotopes, oxygen-18, and carbon-14 concentration in sea water on transects in the European Basin as part of the International Arctic Ocean Expedition 1991, a three-ship expedition. Small volume sampling will be carried out on the Swedish icebreaker ODEN, while large-volume sampling will be done from the German research ship POLARSTERN. The proposed combination of tracers will allow the establishing of renewal time scales for both deep and shallow water masses. Additionally, the pattern of tracers in deep basins will give indications of the origin of these deep water masses and the processes by which they were formed.