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Metadata Report for BODC Series Reference Number 1725490


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI Ocean Surveyor 150kHz vessel-mounted ADCP  current profilers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Miss Charlotte Marcinko
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Oceans 2025
Oceans 2025 Theme 10
Oceans 2025 Theme 10 SO4
 

Data Identifiers

Originator's Identifier ADP379TT
BODC Series Reference 1725490
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2012-08-11 09:36
End Time (yyyy-mm-dd hh:mm) 2012-08-11 23:58
Nominal Cycle Interval 120.0 seconds
 

Spatial Co-ordinates

Start Latitude 59.11690 N ( 59° 7.0' N )
End Latitude 59.37450 N ( 59° 22.5' N )
Start Longitude 17.66690 W ( 17° 40.0' W )
End Longitude 18.34590 W ( 18° 20.8' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 11.0 m
Maximum Sensor or Sampling Depth 391.0 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Sensor fixed with measurements made at multiple depths within a fixed range (e.g. ADCP) - 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 or Sampling Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
DBINAA010MetresDepth (spatial coordinate) of ADCP bin relative to water surface {bin depth} in the water body
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
ACYCAA011DimensionlessSequence number
ALATGP011DegreesLatitude north relative to WGS84 by unspecified GPS system
ALONGP011DegreesLongitude east relative to WGS84 by unspecified GPS system
APEWAS011Centimetres per secondEastward velocity of measurement platform relative to ground surface by Ashtech GPS
APNSAS011Centimetres per secondNorthward velocity of measurement platform relative to ground surface by Ashtech GPS
DSRNCV011KilometresDistance travelled
ASAMSP002DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 1
ASAMSP022DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 2
ASAMSP032DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 3
ASAMSP042DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 4
LCEWAS012Centimetres per secondEastward velocity of water current (Eulerian measurement) in the water body by shipborne acoustic doppler current profiler (ADCP)
LCNSAS012Centimetres per secondNorthward velocity of water current (Eulerian measurement) in the water body by shipborne acoustic doppler current profiler (ADCP)
LERRAS012Centimetres per secondError velocity of water current in the water body by shipborne acoustic doppler current profiler (ADCP)
LREWAS012Centimetres per secondEastward velocity of water current relative to moving platform in the water body by shipborne acoustic doppler current profiler (ADCP)
LRNSAS012Centimetres per secondNorthward velocity of water current relative to moving platform in the water body by shipborne acoustic doppler current profiler (ADCP)
LRZAAS012Centimetres per secondUpward velocity of water current in the water body by shipborne 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 Quality Report

The following was taken from the D379 cruise report. For more detailed information please refer to the cruise report.

Data stopped logging to the raw data file from the 75kHz VMADCP at 16:35 GMT on Julian day 220 until the data file was cycled at 09:30 GMT on Julian day 221. This loss of data was unexplained; hourly watch checks had shown the instrument was working well throughout the period in question. An approximate 17 hour gap in the 75kHz VMADCP data stream thus exists during this period.

A gap of approximately 24 hours also exists in both the 150 kHz and 75kHz VMADCP data from Julian day 223 to 224. This is due to a problem with the Ashtech ADU5 navigation system which required the starboard boat deck antenna to be replaced.


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

RD Instruments- Ocean Surveyor 150kHz Vessel mounted ADCP.

Long-Range Mode
Vertical Resolution Cell Size3 Max. Range (m)1 Precision (cm/s)2
4m 325 - 350 30
8m 375 - 400 19
High-Precision Mode
Vertical Resolution Cell Size3 Max.Range (m)1 Precision (cm/s)2
4m 200 - 250 12
8m 220 - 275 9

1 Ranges at 1 to 5 knots ship speed are typical and vary with situation.
2 Single-ping standard deviation.
3 User's choice of depth cell size is not limited to the typical values specified.

Profile Parameters

  • Velocity long-term accuracy (typical): ±1.0%, ±0.5cm/s
  • Velocity range: -5 to 9m/s
  • # of depth cells: 1 - 128
  • Max ping rate: 1.5

Bottom Track

Maximum altitude (precision <2cm/s): 600m

Echo Intensity Profile

Dynamic range: 80dB
Precision: ±1.5dB

Transducer & Hardware

Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W

Standard Sensors

Temperature (mounted on transducer)

  • Range: -5° to 45°C
  • Precision: ±0.1°C
  • Resolution: 0.03°

Environmental

Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*

*later instruments have greater range.

Web Page

Further details can be found in the manufacturer's website or in the specification sheet.

BODC Processing

The vessel mounted ADCP data from Discovery cruise D379 were converted from Pstar format into the BODC internal format, a netCDF subset, to allow use of in-house visualisation tools. The table below shows the mapping of originator variables to BODC Parameter codes.

Originator's Variable Originator's Units Description BODC Parameter Code BODC Units Comment
2.bindepth m Depth below sea surface (ADCP bin) DBINAA01 m -
3.evelcal cm/s Eastward current velocity (relative to moving platform) in the water body by shipborne acoustic doppler current profiler (ADCP) LREWAS01 cm/s -
4.nvelcal cm/s Northward current velocity (relative to moving platform) in the water body by shipborne acoustic doppler current profiler (ADCP) LRNSAS01 cm/s -
5.velvert cm/s Upward current velocity in the water body by shipborne acoustic doppler current profiler (ADCP) LRZAAS01 cm/s -
6.velerr cm/s Current velocity error in the water body by shipborne acoustic doppler current profiler (ADCP) LERRAS01 cm/s -
7.intense1 db Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 1 ASAMSP00 db -
8.intense2 db Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 2 ASAMSP02 db -
9.intense3 db Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 3 ASAMSP03 db -
10.intense4 db Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 4 ASAMSP04 db -
11.good3bm % Dummy channel ZZZZZZ01 % To be deleted after transfer/screening
12.verr % Dummy channel ZZZZZZ02 % To be deleted after transfer/screening
13.2+bmbad % Dummy channel ZZZZZZ03 % To be deleted after transfer/screening
14.good4bm % Dummy channel ZZZZZZ04 % To be deleted after transfer/screening
15.ve cm/s Eastward velocity (over ground) of measurement platform by Ashtech GPS APEWAS01 cm/s -
16.vn cm/s Eastward velocity (over ground) of measurement platform by Ashtech GPS APNSAS01 cm/s -
17.absve cm/s Eastward current velocity (Eulerian) in the water body by shipborne acoustic doppler current profiler (ADCP) LCEWAS01 cm/s -
18.absvn cm/s Northward current velocity (Eulerian) in the water body by shipborne acoustic doppler current profiler (ADCP) LCNSAS01 cm/s -
19.lat - Latitude north (WGS84) by unspecified GPS system ALATGP01 - -
20.lon.intense4 - Longitude east (WGS84) by unspecified GPS system ALONGP01 - -
21.distrun km Distance travelled DSRNCV01 km -

The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.

Extended Ellett Line Discovery cruise D379 75kHz and 150kHz Shipboard ADCP Originator data processing

The following was taken from the D379 cruise report. For more detailed information please refer to the cruise report.

Data were acquired using the RD Instruments VmDAS software package version 1.46.

75kHz VM-ADCP setup

Variable Setting
Number of Bins 96
Bin size 8m
Blanking distance 8m
Transducer depth 5.3m
Beam angle 30 degrees

150kHz VM-ADCP setup

Variable Setting
Number of Bins 96
Bin size 4m
Blanking distance 4m
Transducer depth 5.3m
Beam angle 30 degrees

Processing

The deck unit had firmware upgrades to VDMS 23.17 following the March 2008 refit. Both PCs ran RDI software VmDAS v1.46.

Gyro heading, and GPS Ashtech heading, location and time were fed as NMEA messages into the serial ports of the controlling PC and VmDAS was configured to use the gyro heading for co-ordinate transformation. VmDAS logs the PC clock time, stamps the data (start of each ensemble) with that time, and records the offset of the PC clock from GPS time. This offset was applied to the data in the PSTAR processing path before merging with navigation.

Both instruments were configured to run in 'arrowband' range over resolution mode. Bottom tracking was used during the steam north from Southampton, through the Irish Sea, to the start of the Ellett Line in the Sound of Mull and until water depths became deeper than 300m. The VM-ADCP processing path followed an identical route to that developed in 2001 for the 75kHz VM-ADCP (RRS Discovery Cruise D253).

Calibration

A calibration of both VM-ADCPs was achieved using bottom tracking data available from the departure from Southampton travelling north through the Irish Sea. No further calibration was deemed necessary from inspection of the processed data during the cruise. Using long, straight, steady speed sections of standard two minute ensemble profiles over reasonably constant bottom depth the following calibrations for mis-alignment angle Φ, and necessary amplification (tilt) A, were derived by comparing GPS derived component vectors of the vessel speed and direction with processed VM-ADCP bottom track determined component vectors of the vessel speed and the direction:

150kHz Φ A
mean -0.643418649 1.007194314
s.d. 0.107562285 0.002050008
75kHz Φ A
mean 3.409524779 0.995817247
s.d. 0.167736392 0.003402573

The calibration for the 150kHz VM-ADCP was very similar to that obtained on D369. As the 75kHz VM-ADCP had recently been replaced, no previous calibration was available for comparison.


Project Information

Oceans 2025 - The NERC Marine Centres' Strategic Research Programme 2007-2012

Who funds the programme?

The Natural Environment Research Council (NERC) funds the Oceans 2025 programme, which was originally planned in the context of NERC's 2002-2007 strategy and later realigned to NERC's subsequent strategy (Next Generation Science for Planet Earth; NERC 2007).

Who is involved in the programme?

The Oceans 2025 programme was designed by and is to be implemented through seven leading UK marine centres. The marine centres work together in coordination and are also supported by cooperation and input from government bodies, universities and other partners. The seven marine centres are:

  • National Oceanography Centre, Southampton (NOCS)
  • Plymouth Marine Laboratory (PML)
  • Marine Biological Association (MBA)
  • Sir Alister Hardy Foundation for Marine Science (SAHFOS)
  • Proudman Oceanographic Laboratory (POL)
  • Scottish Association for Marine Science (SAMS)
  • Sea Mammal Research Unit (SMRU)

Oceans2025 provides funding to three national marine facilities, which provide services to the wider UK marine community, in addition to the Oceans 2025 community. These facilities are:

  • British Oceanographic Data Centre (BODC), hosted at POL
  • Permanent Service for Mean Sea Level (PSMSL), hosted at POL
  • Culture Collection of Algae and Protozoa (CCAP), hosted at SAMS

The NERC-run Strategic Ocean Funding Initiative (SOFI) provides additional support to the programme by funding additional research projects and studentships that closely complement the Oceans 2025 programme, primarily through universities.

What is the programme about?

Oceans 2025 sets out to address some key challenges that face the UK as a result of a changing marine environment. The research funded through the programme sets out to increase understanding of the size, nature and impacts of these changes, with the aim to:

  • improve knowledge of how the seas behave, not just now but in the future;
  • help assess what that might mean for the Earth system and for society;
  • assist in developing sustainable solutions for the management of marine resources for future generations;
  • enhance the research capabilities and facilities available for UK marine science.

In order to address these aims there are nine science themes supported by the Oceans 2025 programme:

  • Climate, circulation and sea level (Theme 1)
  • Marine biogeochemical cycles (Theme 2)
  • Shelf and coastal processes (Theme 3)
  • Biodiversity and ecosystem functioning (Theme 4)
  • Continental margins and deep ocean (Theme 5)
  • Sustainable marine resources (Theme 6)
  • Technology development (Theme 8)
  • Next generation ocean prediction (Theme 9)
  • Integration of sustained observations in the marine environment (Theme 10)

In the original programme proposal there was a theme on health and human impacts (Theme 7). The elements of this Theme have subsequently been included in Themes 3 and 9.

When is the programme active?

The programme started in April 2007 with funding for 5 years.

Brief summary of the programme fieldwork/data

Programme fieldwork and data collection are to be achieved through:

  • physical, biological and chemical parameters sampling throughout the North and South Atlantic during collaborative research cruises aboard NERC's research vessels RRS Discovery, RRS James Cook and RRS James Clark Ross;
  • the Continuous Plankton Recorder being deployed by SAHFOS in the North Atlantic and North Pacific on 'ships of opportunity';
  • physical parameters measured and relayed in near real-time by fixed moorings and ARGO floats;
  • coastal and shelf sea observatory data (Liverpool Bay Coastal Observatory (LBCO) and Western Channel Observatory (WCO)) using the RV Prince Madog and RV Quest.

The data is to be fed into models for validation and future projections. Greater detail can be found in the Theme documents.


Oceans 2025 Theme 10

Oceans 2025 is a strategic marine science programme, bringing marine researchers together to increase people's knowledge of the marine environment so that they are better able to protect it for future generations.

Theme 10: Integration of Sustained Observations in the Marine Environment spans all marine domains from the sea-shore to the global ocean, providing data and knowledge on a wide range of ecosystem properties and processes (from ocean circulation to biodiversity) that are critical to understanding Earth system behaviour and identifying change. They have been developed not merely to provide long-term data sets, but to capture extreme or episodic events, and play a key role in the initialisation and validation of models. Many of these SOs will be integrated into the newly developing UK Marine Monitoring Strategy - evolving from the Defra reports Safeguarding our Seas (2002) and Charting Progress (2005), thus contributing to the underpinning knowledge for national marine stewardship. They will also contribute to the UK GOOS Strategic Plan (IACMST, 2006) and the Global Marine Assessment.

Weblink: http://www.oceans2025.org/


Oceans 2025 Theme 10, Sustained Observation Activity 4: The Extended Ellett Line

The Ellett Line (begun in 1975 and since 1996 the Extended Ellett Line from Scotland to Iceland) crosses important north Atlantic Meridional Overturning Circulation (MOC) components and thus provides an additional contribution to understanding the north Atlantic response to climate change. Sustained Observation Activity (SO) 4 will repeat this section annually collecting a wide variety of physical and biogeochemical measurements, and will, to enhance the time variable component, make use of Argo floats and gliders. SO 4 will be implemented by physical, biological and chemical scientists at the National Oceanography Centre, Southampton (NOCS) and the Scottish Association for Marine Science (SAMS).

SO 4 formally contributes to the Department for Environment, Food and Rural Affairs (DEFRA)-funded Marine Environmental Change Network (MECN). Established in 2002 to coordinate and promote the collection and utilisation of marine time-series and long-term data sets, the goal of the network is to use long-term marine environmental data from around the British Isles and Ireland to separate natural fluctuations from global, regional and local anthropogenic impacts.

The specific deliverables for SO 4 are:

  • A time series of the evolution of the hydrography of the northeast Atlantic, together with a more formal understanding of the causes of any changes observed
  • An archived data set available to the international community via the British Oceanographic Data Centre (BODC)
  • A platform for further scientific research

More detailed information on this Work Package is available at pages 15 - 16 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10

Weblink: http://www.oceans2025.org/


Data Activity or Cruise Information

Cruise

Cruise Name D379
Departure Date 2012-07-30
Arrival Date 2012-08-17
Principal Scientist(s)Colin R Griffiths (Scottish Association for Marine Science)
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