Metadata Report for BODC Series Reference Number 491307
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
SeaDataNet Quality Flags
Metadata Summary
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Problem Reports
No Problem Report Found in the Database
Data Access Policy
Public domain data
These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.
The recommended acknowledgment is
"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."
Narrative Documents
Sea-Bird SBE 19 and SBE 19plus SEACAT Profiler CTDs
The SBE 19 SEACAT Profiler is a self-contained, battery powered, pumped CTD system designed to measure conductivity, temperature, and pressure in marine or fresh water environments to depths of 10,500 meters. It was replaced by the SBE 19plus model in 2001. An updated version of this instrument is the SBE 19plus V2, which incorporates an electronics upgrade and additional features, with six differentially amplified A/D input channels, one RS-232 data input channel, and 64 MB FLASH memory.
The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by titanium housing for depths up to 7000 m. It is typically used for CTD profiling although a conversion kit is available for mooring deployments. The CTD can also be attached to an SBE 36 CTD Deck Unit and Power/Data Interface Module (PDIM) for real-time operation on single-core armored cable up to 10,000 m.
Specifications
| Parameter | SBE 19 | SBE 19plus |
|---|---|---|
| Temperature | Range: -5 to +35 °C Accuracy: 0.01 °C Resolution: 0.001 °C Calibration: +1 to +32 °C* | Range: -5 to +35 °C Accuracy: 0.005 °C Resolution: 0.0001 °C Calibration: +1 to +32 °C* |
| Conductivity | Range: 0 to 7 S m-1 (0 to 70 mmho cm-1) Accuracy: 0.001 S m-1 Resolution: 0.0001 S m-1 Calibration: 0 to 7 S m-1. Physical calibration over the range 1.4 - 6 S m-1* | Range: 0 to 9 Sm-1 Accuracy: 0.0005 Resolution: 0.00005 (most oceanic waters, resolves 0.4 ppm in salinity); 0.00007 (high salinity waters, resolves 0.4 ppm in salinity); 0.00001 (fresh waters, resolves 0.1 ppm in salinity) Calibration: 0 to 9 S m-1. Physical calibration over the range 1.4 - 6 S m-1* |
| Strain gauge pressure sensor | Range: 0 to100, 150, 300, 500, 1000, 1500, 3000, 5000, 10000 or 15000 psia Accuracy: 0.25% of full scale range (100 - 1500 psia); 0.15% of full scale range (3000 - 15000 psia) Resolution: 0.015% of full scale Calibration: 0 to full scale in 20% steps | Range: 0 to 20, 100, 350, 1000, 2000, 3500 or 7000 m Accuracy: 0.1% of full scale range Resolution: 0.002% of full scale range Calibration: ambient pressure to full scale range in 5 steps |
*Measurements outside this range may be at slightly reduced accuracy due to extrapolation errors.
Options and accessories
Additional sensors can be attached to the CTD, including:
- high accuracy Paroscientific Digiquartz pressure sensor (depth range 0 to 20, 60, 130, 200, 270, 680, 1400, 2000, 4200, 7000 or 10500 m; accuracy 0.02% of full scale; resolution 0.0025% of full scale)
- Dissolved Oxygen (SBE 43 DO Sensor)
- pH* (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor)
- fluorescence
- radiance (PAR)
- light transmission
- optical backscatter (turbidity)
The standard SBE 5M pump may be replaced by an SBE 5P (plastic housing) or 5T (titanium housing) pump for use with dissolved oxygen and/or other pumped sensors. Further details can be found in the manufacturer's SBE 19plus V2 instrument specification or theSBE 19 andSBE 19 plus user guides.
RV Prince Madog Cruise PM6/95 CTD Data Documentation
Introduction
Documentation for the CTD data from a series of cruises in the western Irish Sea carried out by University of Wales, Bangor during 1995 on the RV Prince Madog under the direction of Dr A.E. Hill. The work was supported by NERC grant GR3/9601, "Seasonal Gyres in Shelf Seas".
The data is already calibrated. Coefficients and method are given below. Density has been derived using the formulation recommended in Unesco Tech. reports 36,38,40 (1981).
Instrumentation
The instrument used was a Sea-Bird SBE 19 profiling CTD. In all cases, observed parameters were pressure, temperature and conductivity.
Sampling Protocol
The typical instrument descent rate was 1 m/s. Data were logged on an IBM compatible PC.
Data from the SBE 19 was collected using Seasoft Version 4.211
Data Processing
Data from the SBE 19 were processed with Seasoft Version 4.211
In all cases, data were checked for rogue values and averaged into 1m depth bins. Calibration coefficients were subsequently applied using an in-house program which created the files sent to BODC.
Calibration
Temperature was calibrated using standard reversing thermometers (0.001 °C accuracy) and salinity samples from a rosette. Salinity samples were measured with Autosal Model 8400A. Samples were collected from well mixed regions of the water column to ensure good calibration.
Temperature
Temperature calibration was calculated as a difference:
Temperature = CTD temperature + dT (°C)
Salinity
Salinity calibration was calculated as a ratio:
Salinity = CTD salinity / Sr Cruise PM6_95
| Number of samples | 36 |
|---|---|
| Mean dT | 0.016 |
| Standard deviation dT | 0.004 |
| Mean Sr | 1.002 |
| Standard deviation Sr | 0.0006 |
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Cruise
| Cruise Name | PM6/95 |
| Departure Date | 1995-08-14 |
| Arrival Date | 1995-08-17 |
| Principal Scientist(s) | |
| Ship | Prince Madog |
Complete Cruise Metadata Report is available here
Fixed Station Information
No Fixed Station Information held for the Series
BODC Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
| Flag | Description |
|---|---|
| Blank | Unqualified |
| < | Below detection limit |
| > | In excess of quoted value |
| A | Taxonomic flag for affinis (aff.) |
| B | Beginning of CTD Down/Up Cast |
| C | Taxonomic flag for confer (cf.) |
| D | Thermometric depth |
| E | End of CTD Down/Up Cast |
| G | Non-taxonomic biological characteristic uncertainty |
| H | Extrapolated value |
| I | Taxonomic flag for single species (sp.) |
| K | Improbable value - unknown quality control source |
| L | Improbable value - originator's quality control |
| M | Improbable value - BODC quality control |
| N | Null value |
| O | Improbable value - user quality control |
| P | Trace/calm |
| Q | Indeterminate |
| R | Replacement value |
| S | Estimated value |
| T | Interpolated value |
| U | Uncalibrated |
| W | Control value |
| X | Excessive difference |
SeaDataNet Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
| Flag | Description |
|---|---|
| 0 | no quality control |
| 1 | good value |
| 2 | probably good value |
| 3 | probably bad value |
| 4 | bad value |
| 5 | changed value |
| 6 | value below detection |
| 7 | value in excess |
| 8 | interpolated value |
| 9 | missing value |
| A | value phenomenon uncertain |
| B | nominal value |
| Q | value below limit of quantification |
