SBI WINTER 2004 SURVEY Profiles of Temperature, Salinity, Density, and Nutrients, 1-16 April 2004 By: John P. Christensen (P.I.) Bigelow Laboratory 180 McKown Point W. Boothbay Harbor ME 04575 207-633-9600 jchristensen @ bigelow.org Grant #: NSF (OPP) 0125313 SAMPLING. Early spring sampling was performed in the eastern area of the Shelf-Basin Interactions Project using aircraft. Flights began on 1 April 2004 and finished on 16 April. During this time, we sampled 32 sites on a series of 5 transect lines (Fig. 1). 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. Typically, 4 stations were sampled on each flying day. At each site, a Seabird SBE-19 CTD and a water sampling bottle was deployed through an 25 cm hole augered through the pack-ice. Continuous profiles of pressure, temperature, and salinity were made from the ice hole to either the sediment surface or to about 500 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. About 30 ml of seawater collected from the Niskin bottle were poured into a 50 ml clean dry polyethylene sample bottle. The nutrient sample bottles quickly froze and were kept that way until measurement of nitrate, nitrite, ammonium, phosphate and silicate by the Nutrient Chemistry Laboratory of the Scripps Institute of Oceanography. This Laboratory operates the nutrient autoanalyzer according to WOCE protocols for accuracy and precision. This report is file, SW4RPT9H.pdf, and the text in this file is repeated in the file, README.txt. A map of the achieved sampling sites is file, SW4MAP2D.pdf. The data are reported in seven ASCII comma-separated-value files, one for the station vitae, and five files for the CTD data (one for each of the transect lines), and one file listing the bottle nutrient concentrations (Table 1). The station vitae, S4VITAE4.csv, includes the following columns. Column 1 is the CTD number. Column 2 is the cruise name. The initial time of landing at the station is reported in columns 3-8 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 time of day in decimal hours. Column 8 is the hour difference between GMT and local time. Columns 9-14 list the beginning position of the station. Column 9 is the degrees of north latitude. Column 10 is the minutes of latitude. Column 11 is the north latitude in decimal degrees. Column 12 is the degrees of west longitude. Column 13 is the minutes of longitude. Column 14 is the west longitude in decimal degrees. Column 15 lists the water depth, if less than 400 m, as had been measured with a portable sonic depth-finder. Column 16 lists the sea-ice thickness in cm, and column 17 lists the average drift speed (m/s) during the station based on beginning and ending positions. Dummy values are -99 or -999 and represent no observations. The five CTD files have the following columns. Column 1 is the CTD number. Column 2 is the cruise name. Column 3 is the center pressure of the pressure bin (dbar). Column 4 is the average pressure of all the data in the bin (dbar). Column 5 is the average depth of all data within the bin (meters). Column 6 is the average temperature within the bin (degrees C). Column 7 is the average potential temperature within the bin (degrees C). Column 8 is the average salinity in the bin (psu). Column 9 is the average sigma-t in the bin (kg/m3). Dummy values are -99 or -999 and represent either bad or non-existent data. The nutrient concentrations measured from the Niskin bottle are reported in the file, SW4NUT-7.csv. Column 1 is the cruise name. Column 2 is the CTD# of the CTD data. Column 3 is the center pressure of the pressure bin (dbar). This bin was selected as the CTD profile's bin with the average bin depth which most closely matched the calculated bottle depth. Column 4 is the average pressure of all the data in the bin (dbar). Column 5 is the average depth of all data within the bin (meters). Column 6 is the average temperature within the bin (degrees C). Column 7 is the average potential temperature within the bin (degrees C). Column 8 is the average salinity in the bin (psu). Column 9 is the average sigma-t in the bin (kg/m3). Column 11 is the CTD cast number for the bottle samples. Column 12 was the calculated depth of the Niskin bottle based on the CTD data from the same cast and corrected for the difference in depth between the CTD sensor level and the bottle itself. Concentrations of nitrate, nitrite, ammonium, phosphate, and silicate (in micromoles/liter) are reported in columns 13-17. Dummy values are -99 or -999 and represent either bad or non-existent data. ___________________________________________________________________ Table 1. Listing of all files in this report. This includes the two versions of this report, the one figure, and the seven data files. ___________________________________________________________________ Data Type File name data rows columns Text form of this report README.txt none none This report SW4RPT9H.pdf none none Map of locations SW4MAP2D.pdf none none Station vitae S4VITAE4.csv 34 17 CTDs # 01-02 SW40102E.csv 2082 9 CTDs # 03-12 SW40312E.csv 7852 9 CTDs # 19-28 SW41928E.csv 4610 9 CTDs # 29-35 SW42935E.csv 4312 9 CTDs # 36-41 SW43641E.csv 3202 9 Bottle nutrients SW4NUT-7.csv 166 17