Metadata Report for BODC Series Reference Number 1023868
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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Problem Reports
No Problem Report Found in the Database
Data Access Policy
Open 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.
If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:
"Contains public sector information licensed under the Open Government Licence v1.0."
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.
Instrument Description
150kHz ADCP
An RDI broad band 150 kHz (Ocean Surveyor) phased array style VM-ADCP.
The 150 kHz ADCP is mounted in the hull 1.75 m to port of the keel, 33 m aft of the bow at the waterline and at an approximate depth of 5 m. The instrument is a broad band phased array ADCP with 153.6 kHz frequency and a 30° beam angle.
Further information on VM-ADCP instrumentation can be found in the cruise report.
BODC Processing
The data arrived at BODC as 36 PSTAR files. They were reformatted to the internal NetCDF format. The following table shows how the variables within the PSTAR files were mapped to the appropriate BODC parameter codes.
Originator's variable | Units | Description | BODC Parameter code | Units | Comments |
---|---|---|---|---|---|
Time | seconds | - | - | - | |
bindepth | metres | Bin depth relative to sea surface | DBINAA01 | metres | |
evelcal | cm/s | Eastward velocity from ADCP | LREWAS01 | cm/s | Relative to ship's movement |
nvelcal | cm/s | Northward velocity from ADCP | LRNSAS01 | cm/s | Relative to ship's movement |
velvert | cm/s | Upward current velocity of water column by ADCP | LRZAAS01 | cm/s | |
velerr | cm/s | current velocity error in the water column by ADCP | LERRAS01 | cm/s | |
intense1 | db | beam 1 return | ASAMSP00 | db | |
intense2 | db | beam 2 return | ASAMSP02 | db | |
intense3 | db | beam 3 return | ASAMSP03 | db | |
intense4 | db | beam 4 return | ASAMSP04 | db | |
good3bm | % | notifies when 3 beam solution used to generate abs. velocities | ZZZZZZ01 | % | |
verr | % | it is not known what error this is | ZZZZZZ02 | % | |
2+bmbad | % | percentage of pings where >1 beam is bad | ZZZZZZ03 | % | |
good4bm | % | notifies when 4 beam solution used to generate abs. velocities | ZZZZZZ04 | % | |
ve | cm/s | Eastward velocity (over ground) of measurement platform by Trimble GPS | APEWTR01 | cm/s | |
vn | cm/s | Northward velocity (over ground) of measurement platform by Trimble GPS | APNSTR01 | cm/s | |
absve | cm/s | Absolute eastward velocity of water column by ADCP | LCEWAS01 | cm/s | |
absvn | cm/s | Absolute northward velocity of water column by ADCP | LCNSAS01 | cm/s | |
lat | deg | Latitude north (WGS84) by Trimble GPS | ALATTR01 | deg | |
lon | deg | Longitude east (WGS84) by Trimble GPS | ALONTR01 | deg | |
distrun | km | distance run | - | - | A derived parameter, therefore not transferred |
The data were then visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag. Missing data were marked by setting the data to an appropriate absent data value and absent data quality control flag.
Originator's Data Processing
Sampling Strategy
The RDI broad band 150 kHz (Ocean Surveyor) phased array style VM-ADCP was operated and logged throughout the cruise. The RDI Ocean Surveyor 150 kHz Phased Array VM-ADCP was configured to sample over 120 second intervals with 100 bins of 4m depth and a blank beyond transmit of distance of 4m. The instrument is a broad band phased array ADCP with 153.6 kHz frequency and a 30° beam angle.
Originators Data Processing
Both deck units had firmware upgrades to VMDAS 23.17 after the March 2008 refit. Both PCs ran RDI software VmDAS v1.44. Gyro heading, and GPS Ashtech heading, location and time were fed as NMEA messages into the serial ports of the both PCs 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 processing path before merging with navigation. Full processing details can be found in the cruise report.
Field Calibrations
A calibration of both VM-ADCPs was achieved using bottom tracking data available from the departure from St. John's across the continental shelf. 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 the following calibrations for mis-alignment angle, Ø, and necessary amplification (tilt), A, 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 direction:
- Ø (misalignment angle) = -0.0770 °
A (scaling factor) = 1.0028
Further information on calibration of the VM-ADCP can be found in the cruise report.
Initial Data Inspection
In good weather and calm seas both VM-ADCPs behaved well and agreed very closely. During the latter part of the cruise, severe weather significantly degraded the VM-ADCP data.
The 150 kHz VM-ADCP was in 'Broadband' mode during the transect across the Labrador Sea. However it became apparent that having the VM-ADCPs in 'Broadband' high resolution mode significantly reduced their range penetration in the water column.
More information on the data quality can be found in the cruise report.
Project Information
Oceans 2025 Theme 1: Climate, Ocean Circulation and Sea Level
Through fieldwork, analysis and modelling, Theme 1 will provide detailed knowledge of how the Atlantic, Arctic and Southern Oceans are responding to, and driving, climate change. In combination with geodetic studies, it will also improve our ability to predict global sea level and UK land movements in the century ahead.
The official Oceans 2025 documentation for this Theme is available from the following link: Oceans 2025 Theme 1
Weblink: http://www.oceans2025.org/
Oceans 2025 Theme 1, Work Package 1.2: Atlantic Circulation and Transports
This Work Package is run by the National Oceanography Centre, Southampton (NOCS) and aims to establish whether the Atlantic Meridional Overturning Circulation (MOC) is slowing down, and to relate this to changes in regional storage of heat, freshwater and carbon.
More detailed information on this Work Package is available at pages 8 - 10 of the official Oceans 2025 Theme 1 document: Oceans 2025 Theme 1
Weblink: http://www.oceans2025.org/
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.
Data Activity or Cruise Information
Cruise
Cruise Name | D332 |
Departure Date | 2008-08-20 |
Arrival Date | 2008-09-25 |
Principal Scientist(s) | Sheldon Bacon (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 |