Oxygen concentrations from CTD bottle samples collected during AMT16
Originator's Protocol for Data Acquisition and Analysis
This data originates from analyses on samples collected from upto 12 CTD rosette bottles from 53 CTD casts. Water samples were taken directly from the bottles in the Sea-Bird CTD rosette system using silicon tubing.
Dissolved oxygen concentration was determined by automated Winkler titration with photometric end-point detection (Williamson and Jenkinson, 1982).
References Cited
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 via email in an Excel spreadsheet archived under BODC's accession number PML050128. Sample metadata (CTD cast, bottle number and depth) were checked against information held in the database. There were two discrepancies: CTD037t bottle number 3 was provided with depth 299m, the SeaBird bottle files show a depth of 224m and CTD062s bottle number 1 was provided with depth 183m, the SeaBird bottle files show a depth of 301m. In both cases the data were loaded based on the Niskin bottle number. There were two samples where replicate measurements were provided in the data originator's file, the mean values were entered into the database (CTD013s depths 600m and 1000m).
The concentration data were provided in micromoles per litre. These units for the concentration data were consistent with the BODC parameter code units and no conversion was 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 through rosette sampling bottle and depth.
A parameter mapping table is provided below;
| Originator's Parameter | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| O2 | µmol l -1 | Concentration of oxygen {O 2 } per unit volume of the water body [dissolved phase] by Winkler titration | DOXYWITX | µmol l -1 | n/a |
Data Quality Report
BODC was not advised of any specific quality issues with the data. The data were checked visually and used for the calibration of the CTD sensor. No values were flagged by BODC.
Problem Report
Not relevant to this data set.
