Metadata Report for BODC Series Reference Number 489862
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
Data Description |
|||||||||||||||||||||||||
|
|||||||||||||||||||||||||
Data Identifiers |
|||||||||||||||||||||||||
|
|||||||||||||||||||||||||
Time Co-ordinates(UT) |
|||||||||||||||||||||||||
|
|||||||||||||||||||||||||
Spatial Co-ordinates | |||||||||||||||||||||||||
|
|||||||||||||||||||||||||
Parameters |
|||||||||||||||||||||||||
|
|||||||||||||||||||||||||
|
|||||||||||||||||||||||||
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
Neil Brown MK3 CTD
The Neil Brown MK3 conductivity-temperature-depth (CTD) profiler consists of an integral unit containing pressure, temperature and conductivity sensors with an optional dissolved oxygen sensor in a pressure-hardened casing. The most widely used variant in the 1980s and 1990s was the MK3B. An upgrade to this, the MK3C, was developed to meet the requirements of the WOCE project.
The MK3C includes a low hysteresis, titanium strain gauge pressure transducer. The transducer temperature is measured separately, allowing correction for the effects of temperature on pressure measurements. The MK3C conductivity cell features a free flow, internal field design that eliminates ducted pumping and is not affected by external metallic objects such as guard cages and external sensors.
Additional optional sensors include pH and a pressure-temperature fluorometer. The instrument is no longer in production, but is supported (repair and calibration) by General Oceanics.
Specifications
These specification apply to the MK3C version.
| Pressure | Temperature | Conductivity | |
| Range | 6500 m 3200 m (optional) | -3 to 32°C | 1 to 6.5 S cm-1 |
| Accuracy | 0.0015% FS 0.03% FS < 1 msec | 0.0005°C 0.003°C < 30 msec | 0.0001 S cm-1 0.0003 S cm-1 < 30 msec |
Further details can be found in the specification sheet.
RV Prince Madog Cruise PM1/95 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
Neil Brown Instruments System Mark III CTD In all cases, observed parameters were pressure, temperature and conductivity. The typical instrument descent rate was 1 m/s. Data were logged on an IBM compatible PC. Data from the Neil Brown was collected with EG&G CTD data acquisition module Version 2.02.
Data Processing
Data from the Neil Brown were processed with EG&G Post Processing module Version 1.22
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 here.
Calibration
Temperature
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. The calibration data for each cruise now follows: 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 PM1_95
| Number of samples | 29 |
|---|---|
| Mean dT | 0.016 |
| Standard deviation dT | 0.004 |
| Mean Sr | 1.009 |
| Standard deviation Sr | 0.0002 |
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Cruise
| Cruise Name | PM1/95 |
| Departure Date | 1995-05-30 |
| Arrival Date | 1995-06-02 |
| 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 |
