AMT6 Oxygen concentrations from CTD bottle samples
Originator's Protocol for Data Acquisition and Analysis
This data originates from analyses on samples collected from 27 stations during the cruise. Samples were taken from up to 12 bottles fired during the morning casts.
Measurements of dissolved oxygen were made with an automated Winkler titration system based on that described in Williams and Jenkinson (1982). Oxygen saturation was calculated using the equations for the solubility of oxygen in seawater of Benson and Krause (1984).
References Cited
Benson B.B. and Krause D.Jr., 1984. The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere. Limnology and Oceanography, 29, 620-632.
Williams P.J.Leb. and Jenkinson N.W., 1982. A transportable micro processor controlled precise Winkler titration suitable for field station and shipboard use. Limnology and Oceanography, 27, 576-584.
Instrumentation Description
Not applicable for this data set.
BODC Data Processing Procedures
Data were submitted with the AMT6 Dissolved Inorganic Carbon (DIC) dataset in an Excel spreadsheet archived under BODC's accession number PML030011. Sample metadata (CTD cast, date, latitude, longitude and depth) were checked against information held in the database. There were no discrepancies.
The concentration data were provided in millimoles per cubic metre and the saturation data in percentage saturation. These units for the concentration data were equivalent to the BODC parameter code units (micro-moles per litre) and the saturation data units matched the BODC parameter code unit so no unit conversions were applied.
The data were reformatted and loaded in BODC's samples database under Oracle Relational Database Management System. Data were marked up with BODC parameter codes and loaded into the database. Individual samples were matched by depth for each cast.
A parameter mapping table is provided below;
| Originator's Parameter | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| Oxygen concentration | mmol m -3 | Concentration of oxygen {O2} per unit volume of the water body [dissolved phase] by Winkler titration | DOXYWITX | µmol l -1 | n/a |
| Oxygen saturation | %age satn | Saturation of oxygen {O2} in the water body [dissolved phase] by Winkler titration and computation from concentration using Benson and Krause algorithm | OXYSBW01 | Percent | n/a |
Data Quality Report
The data originator highlighted two samples where the oxygen data were suspect - these have been flagged 'L' in the database. The data originator also suspected H 2 S interference during A6-12 (CTD12). These data have not been flagged.
Problem Report
Not relevant to this data set.
