Metadata Report for BODC Series Reference Number 1080690
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
D321B MSS Microstructure Profiler: Processing undertaken by BODC
96 individual ASCII .TOB files were supplied to BODC by scientists at SAMS. These were accompanied by 96 associated raw (.MRD) data files, as output directly from the profiler.
The .TOB files, representing the definitive version of MSS data (as required for the scientific aims of cruise D321B) were reformatted to BODC's internal QXF (netCDF) format. Latitude, longitude and bathymetry (where available) at the start of each profile were extracted from the ship's underway data stream and merged with the MSS data (using profile start time as the linking mechanism).
As part of the reformatting exercise, variables were also mapped to standard BODC parameter codes as described in the table below:
| Originator' Variable | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| PRESS | dbar | Pressure exerted by water body | PRESPR01 | dbar | - |
| TEMPcor | °C | Temperature of water body | TEMPPR01 | °C | - |
| vel | dbar s-1 | Downward velocity of sensor package in the water body | CTDLOWRT | m s-1 | It has been assumed that dbar s-1 and m s-1 are numerically equivalent within the accuracy of the measurement. |
| shear1 | s-1 | Shear in the water body by turbulence profiler shear sensor | EPSPSC01 | s-1 | - |
| shear2 | s-1 | Shear in the water body by secondary turbulence profiler shear sensor | EPSPSC02 | s-1 | - |
| sal | - | Practical salinity of the water body, with no calibration against independent measurements | PSALCU01 | - | - |
| BVF | s-2 | Brunt-Vaisala frequency squared of the water body by turbulence profiler precision CTD | BVFSTP01 | s-2 | - |
| epsilon | W kg-1 | Log10 turbulent kinetic energy dissipation {epsilon} per unit mass of the water body by turbulence profiler shear sensor | EPSIPM01 | log10(W kg -1) | A log10 was applied to original values during transfer |
| sig_t | kg m-3 | - | - | - | Not taken through transfer |
The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked with an appropriate quality control flag, whilst missing data were highlighted by assigning an appropriate absent data value and applying a quality control flag.
Note: The raw .MRD files for this cruise are preserved in the BODC archive and can be supplied upon request.
RRS Discovery Cruise D321B Microstructure Profiler: Originator Processing
Sampling Strategy
A total of five microstructure profiling surveys took place during the cruise, each at a distinct locality within the Wyville Thomson basin. In total, 104 individual profiling events were completed between 03/09/2007 and 06/09/2007, all of which were performed with a single MSS090 profiler. The following table summarises the sampling campaign:
| Survey station name | Microstructure profiler deployments | Comments |
|---|---|---|
| M800W | MSS006 - MSS051 | 25 hour station near M800W minilog mooring |
| WT2 | MSS053 - MSS059 | Profile MSS056 was aborted due to a line tangle |
| WT4 | MSS060 - MSS065 | - |
| WT6 | MSS066 - MSS071 | - |
| M800E | MSS072 - MSS109 | 25 hour station near M800E minilog mooring |
NB MSS001-MSS005 and MSS052 were testing events and therefore not included in the total deployment count.
The microstructure profiler was deployed from a winch mounted on the gunnel of the starboard quarter of the ship. 1000 metres of neutrally buoyant Kevlar cored conducting cable was used on the winch to allow profiling to a maximum depth of 801 metres. Ultimately, the maximum depth achieved on each profile was dependent on weather conditions and the ship's speed through the water (typically in the region of 0.5 knots, but occasionally as great as 1 knot). As a result, a maximum depth of 630 metres was more typically achieved.
Data Processing
Each profile generated a single raw .MRD file. These were post-processed after the cruise following SAMS standard procedures for MSS data, which utilise the ISW processing software (MSSpro). A summary of the main SAMS processing steps is presented below (as outlined in the report for cruise D340B). More comprehensive details are available in the MSSpro software manual.
SAMS processing steps:
- Conversion of sensor output voltages to shear measurements using the gradient of velocity as a function of pressure through the water column
- Application of calibration coefficients specific to the shear probes
- Checking of shear spectra with Nasmyth's universal spectrum of turbulence in the ocean and subsequent application of a low pass filter to remove high frequency noise from the profiles
- Calculation of the dissipation rate of turbulent kinteic energy (epsilon) over the measurable range from the profiler. Spectral fitting using the Nasmyth spectrum to address those frequencies outside of the range
- Generation of 1 metre-binned ASCII (.tob) files containing the key variables identified by the originator.
Post processing resulted in the creation of 96 individual .tob files from the original 104 profiling events. An aborted deployment (MSS056) is noted in the cruise report. Reasons for the absence of data from the remaining profiles (MSS014, MSS021, MSS035, MSS039, MSS052, MSS081 and MSS105) are not documented, but it is thought that there were data quality issues uncovered at the time of post-cruise processing.
References
Inall M. E., 2009. RRS Discovery Cruise D340b. Dunstaffnage to Govan via Barra Head and the Surrounding Shelf. Internal Report No 265. Scottish Association for Marine Science.
Sherwin T. A. et al., 2007. RRS Discovery Cruise D321b. Reykjavic to Clyde via Rockall, Scotland and the Wyville Thomson Ridge. Internal Report No 255. Scottish Association for Marine Science.
D321B Microstructure Profiler Instrumentation
The microstructure profiler deployed during the cruise was a MSS90 profiler (Serial Number 034), which had undergone modification to enable operation in up to 4000 m water depth. Measurements are made at 380 Hz.
The MSS90 sensor configuration is detailed in the following table:
| Variable Measured | Sensor |
|---|---|
| Pressure | Keller PA8-400 |
| Shear 1 | ISW 6079 |
| Shear 2 | ISW 6081 |
| Fast Response Temperature | Thermometrics FP07 |
| Slow Response Temperature | ISW Pt100 |
| Conductivity | ADM 7polig |
| Acceleration | ADXL203 |
Sea and Sun Technology MSS 90 Microstructure Profiler
The MSS 90 profiler is a multiparameter probe used to measure micro-scale water stratification as well as the intensity of small scale turbulence in the water column in marine and limnic environments. The instrument can be used for free sinking or rising measurements. Its sinking or rising velocity can be adjusted by a combination of weights and buoyancy elements. It has a depth rating of approximately 500 m, samples at 1024 Hz and is equipped with high resolution micro-structure and turbulence sensors (temperature, current shear) and standard CTD sensors (temperature, conductivity, pressure). All microstructure channels have a response time of less than 12 ms. The unit includes internal sensors to control for vibrations and tilt.
The system comprises the profiler, a winch, a probe interface and data aquisition computer. Additional sensors, such as oxygen and optical scattering, can be attached to the profiler. The instrument can support up to a maximum of nine sensors.
Further details can be found in the manufacturer's manual.
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 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/
Data Activity or Cruise Information
Cruise
| Cruise Name | D321B |
| Departure Date | 2007-08-24 |
| Arrival Date | 2007-09-09 |
| Principal Scientist(s) | Toby J Sherwin (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 |
