RRS Discovery cruise D321 discrete salinity bottle samples from CTD bottles
Content Of Data Series
| Parameter | Units | BODC Parameter code | No. of Samples | Comments |
|---|---|---|---|---|
| Practical salinity | PSALBSTX | 443 | From 85 CTD casts |
Originator's Data Processing
Discrete salinity samples were withdrawn from water bottles associated to either a stainless steel CTD unit (A) or titanium CTD unit (B). The stainless steel unit comprised of a Sea-Bird 911+ CTD (S/N 0636), Sea-Bird SBE 32 carousel (S/N 32-37898-0518) and 24 x 20 L OTE water bottles. The titanium unit comprised of a Sea-Bird 911+ CTD (S/N 0637), Sea-Bird SBE 32 carousel (S/N 32-34173-0493) and 24 x 10 L OTE trace metal water bottles. Further information regarding CTD unit configuration can be found from p71 of the cruise report . Samples were analysed using a laboratory salinometer. Salinity samples were primarily used to calibrate the CTDs. Further information regarding sampling strategy, methods and instrumentation can be found from p172 of the cruise report .
BODC Processing
The data arrived at BODC in 85 ASCII format files representing 85 CTD casts. These were reformatted into comma delimited format (. CSV ) and loaded into the BODC Oracle Relational Database Management System. The following table shows how the variables within the source files were mapped to appropriate BODC parameter codes:
| Originator's Parameter | Originator's Units | Parameter description | BODC Parameter code | BODC Units | Comments |
|---|---|---|---|---|---|
| statnum | CTD station number | ||||
| sampnum | CTD station number and rosette position number | ||||
| botsal | dimensionless | Practical salinity via salinometer | PSALBSTX | dimensionless | |
| botsalf | WOCE flag | Converted to BODC quality control flags |
Prior to loading into the database, the reformatted data were visualised in Microsoft Excel using plots of salinity v depth. Suspect data were marked by adding an appropriate quality control flag. Absent data values (represented by -999) were removed. Originator's flags were converted to BODC quality control flags. STATNUM was converted to BODC format. Measurements were assigned unique BODC bottle reference numbers which link to the relevant metadata (eg. depth) of each CTD water bottle fired. Measurements were linked to the correct water bottle using the rosette position identifier (SAMPNUM) provided by the originators. However, the identifier was found to refer to firing sequence for four CTD casts (16236B, 16237B, 16238B and 16282B). This was determined by comparison to hand-written Sea-Bird CTD sheets which log rosette position, firing sequence and salinity sample. The rosette position identifiers were corrected for these casts before loading to the database.
Data Quality Report
None.
Problem Report
None.
