TITLE: SBI Winter 2003 Cruise: Profiles of Temperature, Salinity, and Density

P.I.: John P. Christensen
Bigelow Laboratory
180 McKown Point
W. Boothbay Harbor ME 04575
jchristensen @ bigelow.org

P.I.: Humfrey Melling
Institute of Ocean Sciences
P.O. Box 6000
Sidney BC V8L 4B2 Canada

Funding: NSF (OPP) 0125313
Cruise Dates: 1 - 15 April 2003

SAMPLING. Early spring sampling was performed in the eastern area of the Shelf-Basin Interactions Project 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 152oW longitude. Stations were about 10 km apart along each transect line. Transect lines B, C, and D were at the same spacing; while, lines A and E were 20 km from the nearest transect line. A map of the achieved sampling sites is available (file: SW3LOC4A.pdf). Typically, 4-5 stations were sampled on each flying day. 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. CTD data were processed with Seabird software (Seasoft) and the data binned into 0.5 dbar layers. Data herein are the vertical profiles of temperature, salinity, and density. Nutrient data are not reported here.

The data are reported in 7 ASCII comma-separated-value files, one for the station vitae, and 6 files for the CTD data, one for each of the transect lines (Table 1). In addition, a map is provided as a pdf file (Table 1).

The station vitae (SW3VIT-4.csv) includes the following columns. Column 1 is cruise name. Column 2 is the CTD number. The initial time of landing at the station is reported in columns 3-6 in local time. Column 3 is the month. Column 4 is the sampling day. Column 5 is the hour of the day. Column 6 is the minute of the hour. Column 7 is the hour difference between GMT and local time. Columns 8 and 9 list the beginning position of the station. The latitude (LAT-BEG) and longitude (LONG-BEG) are in decimal degrees. Columns 10 and 11 list the location at the end of the station (LAT-END, LONG-END). Column 12 lists the water depth if less than 390 m. Column 13 lists the sea-ice thickness in cm, and column 14 lists the average drift speed (m/s) during the station based on beginning and ending positions. Dummy values are -99 or -999 and represent the taking of no observations.

The 6 CTD files have the following columns. Column 1 is the CTD number. Column 2 is the center depth of the pressure bins (dbar). Column 3 is the average pressure of all the data in the bin (dbar). Column 4 is the average depth of all data within the bin (meters). Column 5 is the average temperature within the bin (degrees C). Column 6 is the average potential temperature within the bin (degrees C). Column 7 is the average salinity in the bin (psu). Column 8 is the average sigma-t in the bin (mg/L). Dummy values are -99 or -999 and represent either bad or non-existent data.

Table 1. Listing of the 8 data files which accompany this report.

Data  Type                    File name              data rows           columns
Station vitae SW3VIT-4.csv 49 12 Map of locations SW3LOC4A.pdf none none CTDs # 01-09 SW3F0009.csv 2113 8 CTDs # 10-18 SW3F1018.csv 4896 8 CTDs # 19-25 SW3F1925.csv 5016 8 CTDs #26-31, 37-41 SW3F2641.csv 5877 8 CTDs # 32-37 SW3F3237.csv 3302 8 CTDs # 42-49 SW3F4249.csv 5295 8

This report is file Readme.htm