OCEANOGRAPHIC CONDITIONS IN THE CANADA BASIN AT THE END OF WINTER DURING 2014 RECORDED BY THE SCICEX PROGRAM

Abstract:

Submarines offer a unique sampling capability for the Arctic Ocean. They can rapidly transit to anywhere in the Arctic making continuous measurements of ice draft, sea floor depth, temperature, salinity and other properties. They can also collect water samples for a variety of chemical and biological measurements and can be a valuable component of the Arctic Observing System. An agreement with the US Navy continues scientific measurements on transit legs of submarines crossing the Arctic Ocean as phase II of the SCICEX program that was begun in the 1990s. We present results from this program collected during a period of complete ice cover in the western Arctic in spring 2014 by two submarines. Continuous data were recorded with the hull-mounted CTD along 4 crossings of the Canada Basin totaling over 6500 km. Vertical profiles of temperature and salinity were obtained at multidepth stations where the submarine changed depths and from periodic XCTDs. Fresher, Pacific water dominated the upper 150 m of the Canada Basin, but shoaled significantly across the Makarov Basin and onto the Lomonosov Ridge. Discrete water samples also were collected with a horizontal spacing of about 60 km along track and during 12 multidepth stations with 6 sampling depths in the upper 250 m. The water samples are being measured at shore based labs for oxygen isotopes, nutrients, tritium, helium-3, CFCs, SF6, carbonate system variables, particulate carbon and nitrogen and chlorophyll levels. These results will be presented in the context of the hydrographic measurements to provide a unique view of the biogeochemical and physical state of the western Arctic at the end of winter.