Metadata Report for BODC Series Reference Number 1014472


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI Workhorse Long-Ranger ADCP  current profilers
Instrument Mounting subsurface mooring
Originating Country United Kingdom
Originator Prof Toby Sherwin
Originating Organization Scottish Association for Marine Science
Processing Status banked
Project(s) -
 

Data Identifiers

Originator's Identifier WTR_06_07_CO
BODC Series Reference 1014472
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2006-10-28 16:33
End Time (yyyy-mm-dd hh:mm) 2007-09-02 17:33
Nominal Cycle Interval 1800.0 seconds
 

Spatial Co-ordinates

Latitude 60.25000 N ( 60° 15.0' N )
Longitude 8.91650 W ( 8° 55.0' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 680.9 m
Maximum Sensor Depth 1191.47 m
Minimum Sensor Height 33.69 m
Maximum Sensor Height 544.26 m
Sea Floor Depth 1225.16 m
Sensor Distribution Sensor fixed, measurements made at fixed depths - The sensor is at a fixed depth, but measurements are made remotely from the sensor over a range of depths (e.g. ADCP measurements)
Sensor 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 CODE Rank Units Short Title Title
BINNUMBR 0 Dimensionless BinNum Bin number
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
ACYCAA01 1 Dimensionless Record_No Sequence number
PPSBSF01 1 Metres WColHt_SF Depth below surface of the water body by fixed in-situ pressure sensor and correction to zero at sea level and conversion to depth using unspecified algorithm
PTCHEI01 1 Degrees Pitch_(Electromech) Orientation (pitch) of measurement platform by inclinometer
ROLLFG01 1 Degrees Roll_(Fluxgate) Orientation (roll angle) of measurement platform by triaxial fluxgate compass
TEMPPR01 1 Degrees Celsius Temp Temperature of the water body
ASAMAP00 2 Decibels ADCPSA Signal return amplitude from the water body by moored acoustic doppler current profiler (ADCP) beam 1
ASAMAP02 2 Decibels Amplitude2 Signal return amplitude from the water body by moored acoustic doppler current profiler (ADCP) beam 2
ASAMAP03 2 Decibels Amplitude3 Signal return amplitude from the water body by moored acoustic doppler current profiler (ADCP) beam 3
ASAMAP04 2 Decibels Amplitude4 Signal return amplitude from the water body by moored acoustic doppler current profiler (ADCP) beam 4
ASAMAPAV 2 Decibels ADCPSA_avg Signal return amplitude from the water body by moored acoustic doppler current profiler (ADCP) and averaging of all functional beams
DBINAA01 2 Metres BinDep Depth below sea surface (ADCP bin)
LCEWAP01 2 Centimetres per second CurrVelE_ADCP Eastward current velocity (Eulerian) in the water body by moored acoustic doppler current profiler (ADCP)
LCNSAP01 2 Centimetres per second CurrVelN_ADCP Northward current velocity (Eulerian) in the water body by moored acoustic doppler current profiler (ADCP)
LRZAAP01 2 Centimetres per second ADCPVC Upward current velocity in the water body by moored acoustic doppler current profiler (ADCP)
PCGDAP00 2 Percent PercGdADCP1 Acceptable proportion of signal returns by moored acoustic doppler current profiler (ADCP) beam 1
PCGDAP03 2 Percent PercGdADCP3 Acceptable proportion of signal returns by moored acoustic doppler current profiler (ADCP) beam 3
PCGDAP04 2 Percent PercGdADCP4 Acceptable proportion of signal returns by moored acoustic doppler current profiler (ADCP) beam 4
 

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

The series displays a significant degree of mooring knockdown. The instrument manufacturer, Teledyne, considers a pitch or roll greater than 20° to be excessive. As a consequence, warning flags have been assigned to all corresponding current velocities and these particular data cycles should be used with caution.

Data Quality Report

It should be noted that the originator has not applied any corrections for magnetic variation.


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 Long Ranger ADCP

The Workhorse Long-Ranger acoustic doppler current profiler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented broadband signal (75 kHz) and a standard depth rating of 1500m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

The instrument comprises:

Wyville Thomson Ridge Moored Acoustic Doppler Current Profiler: Originator Processing

This document outlines the procedures undertaken by the data originator to process and quality assure ADCP data collected as part of a long-term monitoring programme studying transport across the Wyville Thomson Ridge.

Data Processing

The raw binary data are downloaded from the instrument and converted into Matlab format (one file per deployment) using Teledyne RDI-supplied WinADCP software.

Derived 2-dimensional parameters exported from WinADCP have had bin mapping applied to account for the complex geometry involved in extracting currents relative to earth coordinates. In addition the WinADCP software performs a number of calculations needed to determine velocities.

Wyville Thomson Ridge Moored Acoustic Doppler Current Profiler: Processing undertaken by BODC

Data are sent to BODC in .MAT format with one file provided for each ADCP mooring deployment. These files have undergone some initial processing using WinADCP software, but no detailed validation or correction to the data has subsequently been conducted by the data originator. The original .MAT files are archived at BODC and are available upon request.

A number of key parameters from the original .MAT files, as specified by the data originator, are then reformatted into QXF - a NetCDF subset. On occassion BODC have split the data into several files. During the reformatting exercise, bin depths are calculated in order to produce a 2-dimensional bin depth array:

DBINAA01 = ANDepthmm - RDIBin1Mid -((RDIBinSize*(SerBins-1))
Where:
ANDepthmm = depth below surface of the water body as recorded by the ADCP
RDIBin1Mid = distance from ADCP to middle of first bin
RDIBinSize = bin size
SerBins = bin number

Standard parameter codes, that accurately describe the data and any unit conversions, are assigned. These are detailed in the table below.

Originator' Variable Units Description BODC Parameter Code Units Comments
SerNmmpersec mm s -1 Northward current veolcity in the water body LCNSAP01 cm s -1 Unit conversion applied during transfer by dividing original value by 10
SerEmmpersec mm s -1 Eastward current velocity in the water body LCEWAP01 cm s -1 Unit conversion applied during transfer by dividing original value by 10
SerVmmpersec mm s -1 Upward current velocity in the water body LRZAAP01 cm s -1 Unit conversion applied during transfer by dividing original value by 10
AnDepthmm mm Depth below surface of the water body ADEPZZ01 (previously used PPSBSF01) m Unit conversion applied during transfer by dividing original value by 1000
AnT100thDeg °C (*100) Temperature of the water body TEMPPR01 °C Unit conversion applied during transfer by dividing original value by 100
AnR100thDeg degrees (*100) Roll ROLLFG01 degrees Unit conversion applied during transfer by dividing original value by 100
AnP100thDeg degrees (*100) Pitch PTCHEI01 degrees Unit conversion applied during transfer by dividing original value by 100
SerEA1cnt decibels Orientation signal return amplitude from the water body by ADCP beam 1 ASAMAP00 decibels -
SerEA2cnt decibels Orientation signal return amplitude from the water body by ADCP beam 2 ASAMAP02 decibels -
SerEA3cnt decibels Orientation signal return amplitude from the water body by ADCP beam 3 ASAMAP03 decibels -
SerEA4cnt decibels Orientation signal return amplitude from the water body by ADCP beam 4 ASAMAP04 decibels -
SerEAAcnt decibels Signal return amplitude from the water body by moored ADCP and averaging of all functional beams ASAMAPAV decibels -
SerPG1 % Acceptable proportion of signal returns from ADCP beam 1 PCGDAP00 % -
SerPG2 % Acceptable proportion of signal returns from ADCP beam 2 PCGDAP02 % -
SerPG3 % Acceptable proportion of signal returns from ADCP beam 3 PCGDAP03 % -
SerPG4 % Acceptable proportion of signal returns from ADCP beam 4 PCGDAP04 % -
SerBin - Bin number BINNUMBR - -
- - BODC derived depth below surface (ADCP bin) DBINAA01 m -

The data are screened visually and any spikes, or instrument malfunctions, are highlighted with BODC quality control flags. Series are trimmed at the start/end to remove phases from the mooring deployment/recovery. Subtle/brief phases of mooring adjustment at the start of series are highlighted with caution flags alone.

Documentation is prepared describing the collection, processing and quality of each data series. These are linked to each series to enable standalone use of the data in the future.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2006-10-28
End Date (yyyy-mm-dd) 2007-09-02
Organization Undertaking ActivityScottish Association for Marine Science
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierWTR_2b,c
Platform Categorysubsurface mooring

Wyville Thomson Ridge Mooring: 2b,c

The rig was deployed as part of a long-term monitoring programme examining transport across the Wyville Thomson Ridge.

Deployment cruise (date) D312 (29/10/2006)
Recovery cruise (date) D321B (02/09/2007)
Deployment position 60.25°N, 8.92°W
Water depth (m) 1218

A 1000kg weight was used to anchor the ADCP mooring.

Instruments deployed on the rig

Sensor Serial Number Sample Interval (minutes) Height above sea bed (m)
Teledyne RDI Workhorse 75 kHz ADCP 1644 30 17

Cruise

Cruise Name D312
Departure Date 2006-10-11
Arrival Date 2006-10-31
Principal Scientist(s)John T Allen (National Oceanography Centre, Southampton)
Ship RRS Discovery

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameWyville Thomson Ridge
CategoryOffshore area
Latitude60° 14.70' N
Longitude7° 27.00' W
Water depth below MSL

Wyville Thomson Ridge

The Wyville Thomson Ridge marks the boundary between the Rockall Trough and the Faroe-Shetland Channel. The Ridge is an important area for the study of deep ocean circulation and has been the focus of many studies (particularly CTD surveys), by various institutions, since 1975.

The Wyville Thomson Ridge is also a location of focused mooring activities led by the Scottish Association for Marine Science (SAMS). See Wyville Thomson Ridge Moored ADCP for specific details.

Measurements made along and around the Wyville Thomson Ridge lie within a box bounded by co-ordinates 59° 40' N, 9° 54' W at the southwest corner and 60° 50' N, 5° 00' W at the northeast corner.

Other Series linked to this Fixed Station for this cruise - 776793 776800 776812 776824 776836 776848 776861 776873

Other Cruises linked to this Fixed Station (with the number of series) - 0508S (13) 0511S (13) 0703S (132) 0706S (1) 1403S (1) CD176 (14) D321B (17) D340A (26) D379 (26) JC086 (6) PO300_2 (23)

Fixed Station Information

Station NameWyville Thomson Ridge Moored ADCP
CategoryOffshore area
Latitude60° 14.40' N
Longitude8° 52.20' W
Water depth below MSL1200.0 m

Wyville Thomson Ridge Acoustic Doppler Current Profiler (ADCP) Mooring

Introduction

The Wyville Thomson Ridge is an area of the North Atlantic Ocean floor running in a south easterly direction from the Faroe Bank to the Scottish continental shelf. The most eastern pathway across the Wyville Thomson Ridge marks a noteable boundary between cold and warm deep water at the southern edge of the Faroe-Shetland Channel. To enable monitoring of transport across this region the Scottish Association for Marine Science (SAMS) deployed a succession of Acoustic Doppler Current Profiler (ADCP) moorings (occasionally with auxilliary instrumentation) in the region between 2003 and 2013. These moorings were situated approximately 1.2 km north-west of the formal Faroe end of the Fair Isle-Munken (FIM) line (at approximately 60.2°N, 8.9°W) and constitute part of a larger long term monitoring programme studying the nature of flow across the ridge, and the causes of its variability.

Moored data summary

The following table summarises the SAMS mooring deployments at the Wyville Thomson Ridge:

Year Cruise ID Comments
2003 PO300_2 Ridge top mooring. Deployed with miniloggers.
2003 1403S Ridge top mooring. Deployed with miniloggers and a MicroCAT
2005 CD176 -
2006 0706S -
2006 D312 -
2007 D321B -
2008 0508S Deployed with MicroCATS (which were not recovered)
2009 D340A Mooring lost
2011 0511S -
2012 D379 Deployed with MicroCAT

References

Sherwin, T.J., Griffiths, C.R., Inall, M.E., and Turrell, W.R., 2008. Quantifying the overflow across the Wyville Thomson Ridge into the Rockall Trough, Deep-Sea Research, 55, 4, 396-404.

Other Cruises linked to this Fixed Station (with the number of series) - 0508S (13) 0511S (13) 0706S (1) 1403S (1) CD176 (1) D321B (1) D379 (10) PO300_2 (1)


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