Metadata Report for BODC Series Reference Number 1840592
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 Access Policy
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
Narrative Documents
RD Instruments 300kHz Workhorse Sentinel Acoustic Doppler Current Profiler
Specifications
| Water velocity measurements relative to the ADCP | |
|---|---|
| Maximum velocity | 10 m.s-1 |
| Standard deviation | 130, 45, 25, 12, 5 mm.s-1 for depth cell sizes of 1, 2, 4, 8, 16 m, respectively |
| Minimum time between pings | 0.07 s |
| Maximum profiling range* | 110, 120, 130, 150, 165 m for depth cell sizes of 1, 2, 4, 8, 16 m, respectively |
| Minimum range to start of first depth cell | 3 m |
| Number of depth cells | 1 - 128 cells |
| Depth cell size | 1 - 16 cm |
| Echo Intensity measurements | |
| Uncertainty | ± 1.5 dB |
| Sampling | Uses same depth cells and time intervals as velocity |
| Sensors | |
| Water level resolution | 0.25 m |
| Water level accuracy | ± 5 m over 0-200 m depth |
| Temperature range | -5°C to + 45°C |
| Temperature uncertainty | ± 0.4°C |
| Tilt range | ± 20° |
| Tilt uncertainty | ± 2° |
| Compass uncertainty | ± 5° at 60° magnetic dip angle |
| Compass maximum tilt | 20° |
| Physical and Environmental | |
| Maximum depth | 200 m |
| Operating temperature | -5°C to 60°C |
| Storage Temperature | -5°C to 80°C |
The manufacturer's specification document can be found here
DY054 LADCP Originator's Processing
Sampling Strategy
The following information contains extracts of the DY054 cruise report.
Full water column velocity profiles were collected as part of cruise DY054 between 27 July 2016 and 17 August 2016. The profiles were collected using two Teledyne RDI Workhorse Sentinel-300 ADCPs. The primary downward-looking ADCP was serial number 21028 and the primary upward-looking 300 kHz ADCP was serial number 21029. The instruments were mounted on the CTD rosette for all 38 casts.
Data Processing
The raw ADCP files were processed using version IX_8 (May 2012) of the M.Visbeck and A. Thurnherr MATLAB toolbox (Thurnherr, 2012). The data were submitted to BODC as 38 individual .mat files.
References
Thurnherr, A.M. (2012) How To Process LADCP Data with the LDEO Software (last updated from version IX.8).
DY054 LADCP processing undertaken by BODC
38 LADCP casts from cruise DY054 were submitted to BODC as 38 Matlab files.
The following table shows how the variables were mapped to BODC parameter codes:
| Originator's Variable | Units | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|
| dr.z | m | ADEPZZ01 | m | No unit conversion required |
| dr.u | m/s | LCEWLW01 | cm/s | Unit conversion = *100 |
| dr.v | m/s | LCNSLW01 | cm/s | Unit conversion = *100 |
The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, and missing data by both setting the data to an appropriate value and applying a quality control flag.
Please note - the complete LADCP files (including both raw and processed files) as received from the data originator are available upon request.
Project Information
UK - Overturning in the Subpolar North Atlantic Programme (UK-OSNAP) Programme
UK-OSNAP is part of an international collaboration to establish a transoceanic observing system in the subpolar North Atlantic. The aim is to quantify and understand the Subpolar Gyre's response to local and remote forcing of mass, heat and freshwater fluxes, within the conceptual framework of the Atlantic Meridional Overturning Circulation (AMOC).
UK-OSNAP is developing a new observing system to provide a continuous record of full-depth, trans-basin mass, heat, and freshwater fluxes. Combining these sustained measurements with innovative modelling techniques will enable the project to characterise the circulation and fluxes of the North Atlantic Subpolar Gyre.
UK-OSNAP is funded by the Natural Environment Research Council (NERC). The project is led by the National Oceanography Centre (NOC) with partners in the University of Liverpool, the University of Oxford and the Scottish Association for Marine Science (SAMS). It is a part of international OSNAP that is led by USA and includes 10 further partner groups in Canada, France, Germany, the Netherlands and China. The project involves fieldwork at sea and model studies.
The OSNAP observing system consists of two legs: one extending from southern Labrador to the southwestern tip of Greenland across the mouth of the Labrador Sea (OSNAP West), and the second from the southeastern tip of Greenland to Scotland (OSNAP East). The observing system also includes subsurface floats (OSNAP Floats) in order to trace the pathways of overflow waters in the basin and to assess the connectivity of currents crossing the OSNAP line.
NERC have added an extension to UK-OSNAP, until October 2024. This will result in the UK-OSNAP-Decade: 10 years of observing and understanding the overturning circulation in the subpolar North Atlantic (2014-2024).
Data Activity or Cruise Information
Cruise
| Cruise Name | DY054 |
| Departure Date | 2016-07-27 |
| Arrival Date | 2016-08-17 |
| Principal Scientist(s) | N Penny Holliday (National Oceanography Centre, Southampton) |
| Ship | RRS Discovery |
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 |
