Metadata Report for BODC Series Reference Number 702862
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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Time Co-ordinates(UT) |
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Parameters |
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Problem Reports
No Problem Report Found in the Database
Data quality report
Both pressure and temperature series are short. Constant data values at the end of series were collected after recovery of the moorings and have been flagged M.
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
Aanderaa Water Level Recorder Model 7
The Water Level Recorder (WLR) model 7 is a self-contained, high precision instrument specifically designed for recording of ocean water levels through precise measurement of hydrostatic pressure. The WLR records pressure, temperature and conductivity (optional) at regular intervals, enabling precise variations in water level to be calculated. The pressure sensor consists of an oscillating quartz crystal which shifts frequency with the force applied to it. Temperature is measured by a Fenwall thermistor.
The data from the WLR7 are stored in a solid-state data storage unit (DSU) which can store up to 65,500 ten bit, PDC-4 coded words in a set of EEPROMS. Click the link for further details on theWLR7.
Specifications
Pressure
| Oscillator Frequency | 36-40 kHz |
|---|---|
| Resolution | 0.001% of range |
| Repeatability | ± 0.01% of full scale |
| Integration | 40 s |
| Ranges available | 0 - 700 kPA (60 m) (standard) 0 - 3500 kPa (340 m) (standard) |
Temperature
The thermistor is a Fenwall GB32JM19
| Range | -3 °C to +35 °C |
|---|---|
| Accuracy | ± 0.1 °C |
| Resolution | 0.04 °C |
| Response Time | 30 s |
Conductivity (optional)
| Sensor Type | Conductivity Cell 3094 |
|---|---|
| Ranges | 0 - 77 mmho cm-1 (standard) 0 - 42 mmho cm-1 (on request) |
| Accuracy | ± 0.25 mmho cm-1 |
| Resolution | 0.1% of range |
Further details can be found in the manufacturer's specification sheet.
BODC Processing
Data were received by BODC in ASCII format files. For each instrument there is a file containing pressure and temperature time series.
These series were reformatted to the internal QXF format using BODC transfer function 325. The following table shows how the variables within the file were mapped to the appropriate BODC parameter codes.
| Original parameter name | Original Units | Description | BODC Parameter Code | BODC Units | Comments |
|---|---|---|---|---|---|
| Time | DD/MM/YYYY HH:MI | date and time | AADYAA01 + AAFDZZ01 | day number and day fraction GMT | Conversion by transfer |
| P | decibars | Pressure | PREXPS01 | decibars | |
| T | °C | Temperature | TEMPPR01 | °C |
The deck pressure had not been measured, or removed from the data series, prior to submission of data to BODC. We thus derived a pressure offset from the instrument deployment pressure (calculated from deployment depth and latitude) and the first reading of the pressure time series. All water level recorders were bottom-mounted so the instrument depth was simply the depth of the seabed measured by the ship's echosounder at the time of deployment. The offset was applied to the entire series following the form: Pcorr = Porig - offset where Pcorr is the corrected pressure and Porig the original pressure reading.
Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'. Flags from the originator marking suspect data were retained during transfer and flagged 'L'.
Originator's Data Processing
Sampling Strategy
The water level recorder deployed just off the coast of Pabbay in the Western Isles had a sampling frequency of 12 readings per hour. The instrument included a temperature sensor.
Data Processing
DAF applied the standard manufacturers' calibrations to all data, and produced ASCII files for submission to BODC. Data files were named according to the instrument code (723w) and contained pressure and temperature time series.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
| Start Date (yyyy-mm-dd) | 2005-08-19 |
| End Date (yyyy-mm-dd) | 2005-08-21 |
| Organization Undertaking Activity | Fisheries Research Services Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory) |
| Country of Organization | United Kingdom |
| Originator's Data Activity Identifier | 723w |
| Platform Category | fixed benthic node |
DAF bottom mounted water level recorder, Western Isles (off Pabbay)
The water level recorder (WLR) was located at 56° 49.56' N, 007° 31.57' W in a nominal water depth of 35 m.
The WLR was deployed on 19 August 2005 by the Department of Agriculture and Fisheries (DAF, now known as Marine Scotland Aberdeen Marine Laboratory) on cruise FRV Scotia 1105S (16 August 2005 - 30 August 2005) and recovered on 21 August 2005. Instrumentation details are included in the following table.
| Instrument type | Serial Number | Deployment start | Deployment end | Instrument depth (m) | Comments |
|---|---|---|---|---|---|
| Aanderaa WLR 7 | 1348 | 2005-08-19 | 2005-08-21 | 35 |
Cruise
| Cruise Name | 1105S |
| Departure Date | 2005-08-16 |
| Arrival Date | 2005-08-30 |
| Principal Scientist(s) | James C McKie (Fisheries Research Services Aberdeen Marine Laboratory) |
| Ship | FRV Scotia |
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 |
