This project is part of the SCICEX program, which makes use of U.S. Navy nuclear submarines as a research platform. This is a joint science program between the Arctic Natural Sciences Program, the Office of Naval Research and the operational Navy. This project will analyze samples collected on the SCICEX 98 cruise and will collect and analyze samples from the upcoming SCICEX 99 cruise. The scientific goal is to map the distribution, pathways, and mean residence times of the surface and halocline waters of the Arctic Ocean by means of a number of chemical tracers. This information is important for our understanding of the shelf/basin exchange, the freshwater distribution and circulation, the impact of freshwater on the stability of the stratification of the upper waters, and the possible effect of variability in the freshwater export from the Arctic on deep-water formation in the Greenland, Iceland, Norwegian (GIN) and Labrador seas. Additionally, these data contribute to filling the gaps in the tracer database used for model calibration. The new data will be combined with tracer data sets from previous SCICEX and icebreaker cruises and interpreted in terms of the goals of this project outlined above. This project will provide new results from the Arctic Ocean on the surface water circulation and freshwater balance.
During the SCICEX 98 cruise the team collected 64 oxygen isotope, 64 tritium, 64 helium isotope, and 64 chloroflurocarbon (CFC) samples at 4 surface stations. During SCICEX 99, the science team will collect 10 samples per spiral station for oxygen isotopes, helium isotopes and tritium at a total of 24 spirals stations. The ten samples include 8 depth levels plus 2 replicates. A new sampling method will be applied for CFCs (there were problems with CFC contamination using the flame sealing method in the interior of the submarine during the 97 cruise). The samples will be collected and stored in copper tubes. Using this new method, 50 CFC samples will be collected at 5 of the spiral stations. Additionally, about 200 underway oxygen isotope samples will be collected. For both the SCICEX 98 and 99 cruises a total of 304 tritium, 304 helium isotope, 114 CFC, and 500 oxygen isotope samples will be analyzed.
