TITLE: SHEBA/JOIS bottle cast oxygen data

PI:
Drs. Barry and Evelyn Sherr
Phone: 541-737-4369
Fax: 541-737-2064
Email: sherrb@coas.oregonstate.edu
Website: http://bioloc.coas.oregonstate.edu/SherrLab/index.html

DATA SET OVERVIEW:

This data set represents dissolved oxygen (DO) concentrations and oxygen 
saturation values for discrete water samples collected during bottle casts 
down to 50 m, 120m, or 240 m during the SHEBA drift experiment. Water samples 
for DO were collected from filled Niskin bottles into 125 ml iodine flasks; 
overflowing the flask by several volumes before adding Winkler reagents and 
stoppering. A small volume of freshwater was added around the top of the 
stopper to minimize air contact with the contents of the flask.  Flasks were 
warmed to room temperature, and the freshwater was dried from the stopper, 
before titrating the whole flask. DO concentration (ml l-1) was determined via 
an automated titration procedure using a computer-controlled Brinkman Dosimat 
equipped with a potentiometric electrode (Knapp et al., 1990; Culberson, 
1991). The mean coefficient of variation for duplicate samples was 0.12 %.  
Values are reported as ?M O2. Fractional oxygen saturation (Os) levels were 
calculated using the Garcia and Gordon (1992) modification of the Weiss 
(1970) solubility equations and the Benson and Krause (1984) solubility 
coefficients.  Note that in the printed Equation 8 in Garcia and Gordon 
(1992) the fourth term, A3*Ts2, is an error and should be deleted.  We used 
the corrected equation, with the fourth term removed, in our calculations.

This data set consists of an excel workbook with three worksheets.  The 
first sheet, labeled 'Cast information', contains information about the 
SHEB/JOIS bottle casts, including cast number, date, Julian day of year, 
position as latitude and longitude.  The second worksheet, labeled 
'SHEBAoxygen' presents the oxygen data by station and depth, as both ml/liter 
and uM concentration. Temperature, oC (CTD) and salinity, psu (salinometer) 
data for each depth are also listed.  The third sheet labled 'Corrected 
oxygen saturation' presents the computations used to calculate fractional 
oxygen saturations and the oxygen saturation values. See Sherr and Sherr 
(2003) for a published presentation of these data sets.

References:
Culberson, C.H., 1991. Dissolved oxygen, in WOCE Operations Manual, Volume 3, part 3.1.3:WHP 
Operations and Methods, WOCE Report 68/91, Woods Hole Oceanographic Institution, Woods Hole, 
MA.

Garcia, H.E., Gordon, L.I., 1992. Oxygen solubility in seawater: better fitting equations. Limnology and 
Oceanography 37,1307-1312.

Knapp, G.P., Stalcup, M.C., Stanley, R.J., 1990. Automated oxygen titration and salinity determination. 
Woods Hole Oceanographic Institution Technical Report WHOI-90-35.

Sherr, B.F., Sherr, E.B. 2003. Community respiration/production and bacterial activity in the upper water 
column of the central Arctic Ocean. Deep-Sea Research I, 50:529-542.