2003 Helo Survey ISUS Nitrate Concentrations, Temperature, Salinity, and Density [Christensen, J. and H. Melling]

Summary

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 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 sites 10 through 49, a Seabird CTD (SBE-25) and Satlantic In-Situ Ultraviolet Spectrophotometer (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 ISUS-sensed nitrate concentrations were made from the ice hole to either the sediment surface or to about 390 m. The ISUS was not used at CTD casts 1 through 9. CTD data were processed with Seabird software (Seasoft) and the data binned into 0.5 dbar layers. All basic CTD data are contained in another dataset as well as the nutrient data collected from the water sampling bottles. The ISUS samples at a relatively slow rate (3.5 Hz), and even though repeated vertical profiles were collected at each site, not all pressure bins contained ISUS measurements. Data herein include basic CTD data as well as the ISUS data (in its respective bin) converted to nitrate concentration, and the continuous ISUS nitrate profiles constructed by linearly interpolating binned data between two vertically adjacent ISUS averages. A complete description of the evaluation procedure for these ISUS data is being prepared for publication, so data herein are considered to be in draft form. The data are in csv format.

Data access

ORDER data for delivery by FTP

Additional information

Related projects: SBI
Observational frequency: no set schedule
Spatial type: point
Categories: Oceanography
Platforms: CTD ocean cast
Documentation:

• SW3-ISUS.PDF [144 KB]
• Sw3loc4a.pdf [17 KB]
• Sw3vit-4.csv [5 KB]

Related links:

• companion: 2003 Helo Survey CTD Data [Christensen, J. and H. Melling]
• companion: 2003 Helo Survey Nutrients and Oxygen Isotope Samples [Christensen, J. and H. Melling]
• companion: 2004 Winter Survey Profiles of Temperature, Salinity, Density and Nutrients [Christensen, J.]
• homepage: SBI Data Archive Home Page

Temporal coverage

Begin datetime: 2003-04-01 00:00:00, End datetime: 2003-04-15 23:59:59

Spatial coverage

Minimum latitude: 70.000000, Minimum longitude: -158.000000
Maximum latitude: 73.000000, Maximum longitude: -148.000000

Point of contact

John P. Christensen
Bigelow Laboratory for Ocean Sciences
E-Mail address: jchristensen at bigelow dot org