2003 Helo Survey Nutrients and Oxygen Isotope Samples

As part of the Shelf-Basin Interactions (SBI) project, early spring sampling was performed in the eastern area of the SBI study area using aircraft. Flights began on 1 April 2003 and finished on 15 April. During this time, we sampled 42 sites (49 Conductivity Temperature Depth (CTD) casts) on a series of 5 transect lines which bracketed and were parallel to the SBI current meter mooring line located at 152 W longitude. Stations were about 10 km apart along each transect line. A map of the achieved sampling sites is available (file: Sw3loc4a.pdf) and station locations, sampling dates and times are found in the file, Sw3vit-4.csv. At each site, a Seabird CTD (either a SBE-19 or an SBE-25) and Satlantic ISUS nitrate analyzer with a water sampling bottle was deployed through an 8 inch hole augured through the pack-ice. Continuous profiles of pressure, temperature, salinity, and nitrate concentrations were made from the ice hole to either the sediment surface or to about 390 m and were binned into 0.5 dbar bins. Data from the vertical profiles of temperature, salinity, and density are contained in another dataset. Approximately 60 of seawater were collected from up to 8 sampling depths. Waters were subdivided into 30 ml for dissolved nutrient analyses and 20 ml for determination of the isotopic ratio of 18-O/16-O in the sea water. Samples were frozen for return to Maine. Nutrients (nitrate, nitrite, ammonium, inorganic phosphate, and dissolved silica) were determined by autoanalyzer at the Scripps Institute of Oceanography Nutrient Chemistry Laboratory according to World Ocean Circulation Experiment (WOCE) protocols. The oxygen isotope samples were determined at the University of Maine's Stable Isotope Laboratory with standard mean ocean water as standard. The data are in csv format.