Search the data

Metadata Report for BODC Series Reference Number 1842107


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI 300kHz Workhorse Monitor direct-reading ADCP  current profilers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Penny Holliday
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) UK-OSNAP
 

Data Identifiers

Originator's Identifier 073DL000
BODC Series Reference 1842107
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2017-05-25 08:59
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 61.49976 N ( 61° 30.0' N )
Longitude 19.99770 W ( 19° 59.9' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 5.0 m
Maximum Sensor or Sampling Depth 2195.0 m
Minimum Sensor or Sampling Height 20.0 m
Maximum Sensor or Sampling Height 2210.0 m
Sea Floor Depth 2215.0 m
Sea Floor Depth Source CTDDATA
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
ACYCAA011DimensionlessSequence number
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
LCEWLW011Centimetres per secondEastward velocity of water current (Eulerian measurement) in the water body by lowered acoustic doppler current profiler (ADCP)
LCNSLW011Centimetres per secondNorthward velocity of water current (Eulerian measurement) in the water body by lowered acoustic doppler current profiler (ADCP)

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

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

Teledyne RDI's Workhorse Monitor ADCP

The Workhorse Monitor acoustic doppler current profler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented four beam signal (300, 600 or 1200 kHz) and a standard depth rating of 200m or 600m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

DY078 LADCP Originator's Processing

Sampling Strategy

The following information contains extracts of the DY078 cruise report.

Full water column velocity profiles were collected as part of cruise DY078 between 06 May 2017 and 28 May 2017. The profiles were collected using two Teledyne RDI dual 300 kHz Workhorse master/slave configuration ADCPs. The primary downward-looking ADCP was serial number 13329 and the primary upward-looking 300 kHz ADCP was serial number 4275. The instruments were mounted on the CTD rosette during the casts.

Both ADCPs followed the same configuration as the previous years cruise DY053. The number of depth bins was set to 25, the size of the bins was 10 m, an ambiguity velocy of 2.5 m/s, and the blanking distance set to 8 m (upward ADCP) and 0 m (downward ADCP). Both ADCPs were configured to ping in narrowband mode every 1.5 seconds. The slave pings were synchronized to the master, with a delay of 0.55 seconds between the two. This configuration was kept throughout the cruise.

Data Processing

A total of 70 profiles were collected. 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 70 individual .mat files.

References

Thurnherr, A.M. (2012) How To Process LADCP Data with the LDEO Software (last updated from version IX.8).

DY078 LADCP processing undertaken by BODC

70 LADCP casts from cruise DY078 were submitted to BODC as 70 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 four year (2014 ? 2018) 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 runs for five years from October 2013 and 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 a 2-year extension to UK-OSNAP, until October 2020. This will cover a 2-year deployment of 3 moorings in the Iceland Basin as part of the international OSNAP programme. The moorings will be recovered in 2020.


Data Activity or Cruise Information

Cruise

Cruise Name DY078 (DY079)
Departure Date 2017-05-06
Arrival Date 2017-05-28
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
Q value below limit of quantification