Metadata Report for BODC Series Reference Number 932116
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
Metadata Summary
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Problem Reports
No Problem Report Found in the Database
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
Chernikeeff Aquaprobe Mk5 Electromagnetic Speed Log
The Aquaprobe Mk5 EM Speed Log operates on the principle that a conductor (such as water) passing through an electromagnetic field will create a voltage whose magnitude increases as the speed of the conductor increases. The EM log includes one or two hull-mounted transducers, which generate an electromagnetic field and measure the voltage created by the flow of water through that field, thereby deducing the speed of the vessel through the water.
The EM log has the options of single or twin transducers, single or dual axis speed measurements and gate-valved (retractable) hull fitting or fixed transducers. The microprocessor calibration control ensures a high accuracy through the entire speed range.
Specifications
| Speed Range | ± 40 knots or ± 80 knots |
| Total distance range | 0 to 99999.99 nm |
| System accuracy | |
| Speed < 10 knots | ± 0.02 knots |
| Speed > 10 knots | ± 0.2% |
| Distance | 0.02% of speed |
| Calibrated accuracy | |
| Speed < 10 knots | ± 0.1 knots |
| Speed > 10 knots | ± 1% |
| Distance | 0.02% of speed |
Further details can be found in the manufacturer's specification sheet.
Trimble NT300D Geographical Positioning System (GPS)
The NT300D is a 12-channel GPS receiver with a built in dual-channel radiobeacon receiver. It can transmit positional information with an accuracy of <1 m up to five times per second with a maximum latency of 0.2 seconds. The radiobeacon receiver allows for intelligent and seamless switching between radio beacons, which improves performance and availability. The unit also accepts externally received corrections and allows the user to prioritise between those corrections and the corrections received by the internal beacon receiver. Positioning is based on carrier-phase filtered L1 (carrier frequency) pseudoranges over 183 user-selected datums.
Specifications
| Operating temperature | 0 to 55°C |
| GPS receiver | |
| Update rate | 5 Hz with a latency < 200 ms |
| Differential speed accuracy | 0.2 km h-1 |
| Differential position accuracy | < 1 m RMS at least 5 satellites PDOP < 4 |
| Time to first fix | < 30 s (typical) |
| Beacon receiver | |
| Frequency range | 283.5 to 325 kHz |
| Channel spacing | 500 Hz |
| MSK modulation | 50, 100 and 200 bits s-1 |
| Dynamic range | 100 dB |
| Acquisition time | 2 to 5 s (typical) |
Further details can be found in the manufacturer's specification sheet.
PD04_08 Navigation instrument details
| Instrument type | Make and model | Serial Number | Manufacturer's details available? |
|---|---|---|---|
| GPS | Trimble NT300D | - | Yes |
| Heading compass | Plath Gyro Compass | - | - |
| Bathymetric echo sounder | Simrad EK-60 Scientific Echo sounder EK-60 General Purpose Transceiver with a 120 kHz Split Beam transceiver module (1KW) 38kHz Split Beam transceiver (2KW) | 29431 30138 | Yes |
| Electromagnetic speed log | Chernikeeff Aquaprobe MK5 Naval EM log | - | Yes |
Prince Madog Cruise PD04_08 Navigation Series
Navigation Processing Notes
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Positional data
GPS positions were recorded on a Trimble NT300D Differential GPS and logged each minute to the central data acquisition system. Positions were checked for gaps and improbable speeds. No improbable speeds were found but one gap was found between 15:10 on 13 February 2008 and 09:15 on 14 February 2008. The logging system had been switched off as the ship returned to port overnight. As no measurements were made, this gap has not been interpolated. The data were screened on a graphics workstation and any improbable values flagged suspect.
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Bathymetric data
The echo-sounder is located in the ship's hull, 3 m below the surface. The values recorded by the echo-sounder are not corrected to the surface and have not been corrected for density effects.
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Ship Speed over Ground
The ship speed over the ground was measured using a ship-borne Trimble NT300D Differential GPS. The data have been converted from knots to metres per second by the multiplication of a constant factor = 0.514444. The data were screened on a graphics workstation and any improbable values flagged as suspect.
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Ship Speed through Water
The data have been converted from knots to metres per second by the multiplication of a constant factor = 0.514444. The data were screened on a graphics workstation and any improbable values flagged as suspect.
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Velocity of measurement platform
The velocity of the RV Prince Madog over ground was calculated by an in-house program called 'velcal'. This works by converting RV Prince Madog GPS positions recorded every minute by a Trimble NT300D Differential GPS to great circle positions in radians. The arc of these positions is then used to calculate the distance travelled by the ship in kilometres for both north-south and east-west components. Finally, these components are converted to velocities of centimetres per second. The data were screened on a graphics workstation and any improbable values flagged as suspect.
Prince Madog Cruise PD04_08 Sea Surface Hydrography, Meteorology and Navigation Series
Data acquisition
Surface hydrographic (ship's intake 3 m below surface), meteorology measurements and supplementary navigation data, including ship heading and bathymetric depth were time stamped and logged to a central logging system. The data underwent conversion from raw counts into engineering units and were submitted as daily text files to BODC, at 60 second resolution, for further processing.
BODC underway data processing procedures
All underway sea surface hydrography, meteorology and ship's navigation data were merged into a common QXF file. Navigation was checked for improbable speeds and gaps, visual screening was done for each channel and any additional data calibrations were applied as appropriate.
The QXF file then underwent a further step. This involved using Matlab transfer 378 to split the underway QXF file into three separate QXF files. One contained data for sea surface hydrography, one for meteorological data and the final QXF file held the navigation data.
Each data channel was visually inspected on a graphics workstation and any spikes or periods of dubious data were flagged as suspect. The capabilities of the workstation screening software allows all possible comparative screening checks between channels (e.g. to ensure corrected wind data have not been influenced by changes in ship's heading). The system also has the facility of simultaneously displaying the data and the ship's position on a map to enable data screening to take oceanographic climatology into account.
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 3: Shelf and Coastal Processes
Over the next 20 years, UK local marine environments are predicted to experience ever-increasing rates of change - including increased temperature and seawater acidity, changing freshwater run-off, changes in sea level, and a likely increase in flooding events - causing great concern for those charged with their management and protection. The future quality, health and sustainability of UK marine waters require improved appreciation of the complex interactions that occur not only within the coastal and shelf environment, but also between the environment and human actions. This knowledge must primarily be provided by whole-system operational numerical models, able to provide reliable predictions of short and long-term system responses to change.
However, such tools are only viable if scientists understand the underlying processes they are attempting to model and can interpret the resulting data. Many fundamental processes in shelf edge, shelf, coastal and estuarine systems, particularly across key interfaces in the environment, are not fully understood.
Theme 3 addresses the following broad questions:
- How do biological, physical and chemical processes interact within shelf, coastal and estuarine systems, particularly at key environmental interfaces (e.g. coastline, sediment-water interface, thermocline, fronts and the shelf edge)?
- What are the consequences of these interactions on the functioning of the whole coastal system, including its sensitivity and/or resilience to change?
- Ultimately, what changes should be expected to be seen in the UK coastal environment over the next 50 years and beyond and how might these changes be transmitted into the open ocean?
Within Oceans 2025, Theme 3 will develop the necessary understanding of interacting processes to enable the consequences of environmental and anthropogenic change on UK shelf seas, coasts and estuaries to be predicted. Theme 3 will also provide knowledge that can improve the forecasting capability of models being used for the operational management of human activities in the coastal marine environment. Theme 3 is therefore directly relevant to all three of NERC's current strategic priorities; Earth's Life-Support Systems, Climate Change, and Sustainable Economies
The official Oceans 2025 documentation for this Theme is available from the following link: Oceans 2025 Theme 3
Weblink: http://www.oceans2025.org/
Oceans 2025 Theme 3, Work Package 3.3: Bottom Boundary Layer, Optics and Suspended Sediments Processes
This Work Package (WP) is a combination of Work Package 3.3 and 3.4 as proposed in the original Oceans 2025 proposal. It continues and expands the research undertaken in the Proudman Oceanographic Laboratory Dee Experiment project.
Sediment transport process models underpin scientific ability to predict the entrainment of sediments into the water column and the transport of sediments for forecasting seabed and coastal morphodynamic evolution. The difficulty in achieving accurate process models lies with the complex inter-dependence of sediment processes in the bottom boundary layer. Near the bed, the fundamentals of sediment transport are governed by interactions between the sediment transport triad; the bed, the hydrodynamics and the mobile sediments. These three components interrelate, being mutually interactive and interdependent.
POL aim to use a combination of high-frequency underwater acoustics and laser optical measurements to make co-located simultaneous measurements of the triad. These measurements provide an observational framework capable of assessing and advancing the latest sediment transport models available. These measurements will be made in a range of environments, with the objective of achieving significant advances in understanding and modelling capability in coastal sediment transport. POL will also address the dynamics of suspended sediment behaviour in the context of sediment supply to the coastal zone from estuaries, and of coastal water column optical properties. Ths will allow improvement of the modelling accuracy of coastal suspended sediment transport and enable development of a new description of sediment suspension and water opacity that will improve simulation of coastal primary productivity.
The specific objectives are:
- Assess process-based models over different sediment types, cohesive to non-cohesive
- Investigate intra-wave and turbulence processes over flat and rippled beds to improve process based sediment transport models; parameterisation of the process modelling output for input into large-scale area models
- Advance the description and parameterisation of the impact benthic biota has on sediment transport processes (jointly with the Plymouth Marine Laboratory (PML))
- Acquire new knowledge of the dynamics of sediment flocculation and its impact on suspended particulate material (SPM) in shelf seas and estuaries
- Provide preliminary formulations for aggregation-disaggregation and test these formulations using shelf sea models of the Eastern Irish Sea
- Develop understanding of the processes that affect the sediment fluxes between estuaries and the adjacent shelf sea.
- Derive and apply formulations of the effects of SPM on optical attenuation and absorption and assess their potential impact on primary productivity using existing models
Fieldwork
The study site chosen by POL for this research was the Dee Estuary, Liverpool Bay. POL performed fieldwork in the Hilbre Channel on the eastern side of the Estuary and the Welsh Channel on the western exit of the Estuary, with emphasis placed on two repeat stations, HC and WC. The fieldwork under Work Package 3.3 commenced in April 2007 and has been summarised below:
| Cruise | Dates | Hilbre Channel | Welsh Channel |
|---|---|---|---|
| PD06_07 | 2007-04-16 to 2007-04-19 | 18 hour CTD station Mooring recovery | 15 hour CTD station Mooring recovery |
| PD04_08 | 2008-02-12 to 2008-02-15 | 25 hour CTD station 2 x mooring deployment | 19 hour CTD station 1 x mooring deployment |
| PD02_09A | 2009-02-02 to 2009-02-04 | 25 hour CTD station 1 x mooring deployment | 22 hour CTD station 1 mooring deployment |
| PD06_09 | 2009-03-03 to 2009-03-05 | 25 hour CTD station Mooring recovery | 18 hour CTD station Mooring recovery |
More detailed information on this Work Package is available at pages 8 - 9 and 9-10 of the official Oceans 2025 Theme 3 document: Oceans 2025 Theme 3
Weblink: http://www.oceans2025.org/
Proudman Oceanographic Laboratory Dee Experiment
Introduction
Sediment transport process models are a vital tool in allowing scientists to predict sediment transport and forecast seabed and coastal morphodynamic evolution. It is however, difficult to obtain accurate models due to the complex inter-dependence of sediment processes in the bottom boundary layer. This inter-dependence is governed by interactions between the sediment transport triad; the bed, the hydrodynamics and the mobile sediments.
Scientific Objectives
- To use a varying suite of instruments to make co-located measurements of the sediment triad
- To provide a framework to allow assessment and improvement of the latest sediment transport models
- To address dynamics of suspended sediments in terms of supply of material to the coastal zone from estuaries
- Development of a new description of suspended sediment and water opacity to improve simulation of coastal primary productivity
Fieldwork
The study site chosen by POL for this research was the Dee Estuary, Liverpool Bay. POL performed fieldwork in the Hilbre Channel on the eastern side of the Estuary and the Welsh Channel on the western exit of the Estuary, with emphasis placed on two repeat stations, HC and WC. The fieldwork started in February 2005 and has been summarised below:
| Cruise | Dates | Hilbre Channel | Welsh Channel |
|---|---|---|---|
| PD03_05 | 2005-02-03 to 2005-02-04 | 25 hour CTD station 3 x mooring deployments | 13 hour CTD station 1 mooring deployment |
| PD07_05 | 2005-03-03 to 2005-03-04 | 23 hour CTD station Mooring recovery | 19 hour CTD station Mooring recovery |
| PD05_06 | 2006-02-08 to 2006-02-10 | 24 hour CTD station 2 x mooring deployment | 22 hour CTD station 1 mooring deployment |
| PD09_06 | 2006-03-06 to 2006-03-09 | 23 hour CTD station Mooring recovery | 25 hour CTD station Mooring recovery |
| PD04_07 | 2007-03-13 to 2007-03-16 | 25 hour CTD station 2 x mooring deployment | 25 hour CTD station 1 mooring deployment |
Funding
The Dee Experiment project was core funded by POL under Programme 2 (Shallow coastal seas) Theme 5 (Coastal and sediment processes) of POL's Science Programme 2001 - 2006. From March 2007 onwards, this core funding was replaced by funding from NERC's Oceans 2025 programme and the Dee Experiment research continued as part of Oceans 2025 Work Package 3.3.
Data Activity or Cruise Information
Cruise
| Cruise Name | PD04/08 |
| Departure Date | 2008-02-12 |
| Arrival Date | 2008-02-15 |
| Principal Scientist(s) | Alejandro J Souza (Proudman Oceanographic Laboratory) |
| Ship | RV Prince Madog |
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 |
