Metadata Report for BODC Series Reference Number 1022853
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 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
National Oceanography Centre (NOC) Nitrate Sensor SUV6
The NOC SUV-6 is a UV absorption spectrophotometer used for nitrate (NO3 -) measurements in the ocean. It measures the absorption of light by water in the ultraviolet spectrum, which provides the concentration of nitrate. A Xenon flash lamp, pulsed at 8 Hz, projects a beam of light into the sea water, which is returned to a spectrometer by a retroreflector.
The instrument can be deployed on platforms such as oceanographic profilers, undulators or moorings, or used as part of a shipboard through-flow system. It has a sampling rate of 1 or 2 Hz (with selectable averaging) and absorbs at six wavelengths in the range of 205 nm to 280 nm allowing compensation for halides and, possibly, organics. It can be normalised to a selected channel, and is rated to either 500 m (shallow version) or 6000 m (deep version). Both analogue voltage and serial digital (RS232) outputs are available.
The sensor was developed by the Underwater Systems Laboratory (USL) group within NOC's National Marine Facilities (NMF) Division in association with Valeport Ltd. It was based on a prototype design developed by the Institute of Oceanographic Sciences in conjunction with the Optoelectronic Research Centre, University of Southampton.
Specifications
| Path length | 70 or 200 mm |
| Nitrate concentration | 0 to 400 µM (70 mm path length) 0 to 100µM (200 mm path length) |
| Detection limit | 0.2 µM |
| Accuracy | ± 0.2µM |
| Absorption range | 220 to 280 nm |
Sea-Bird Dissolved Oxygen Sensor SBE 43 and SBE 43F
The SBE 43 is a dissolved oxygen sensor designed for marine applications. It incorporates a high-performance Clark polarographic membrane with a pump that continuously plumbs water through it, preventing algal growth and the development of anoxic conditions when the sensor is taking measurements.
Two configurations are available: SBE 43 produces a voltage output and can be incorporated with any Sea-Bird CTD that accepts input from a 0-5 volt auxiliary sensor, while the SBE 43F produces a frequency output and can be integrated with an SBE 52-MP (Moored Profiler CTD) or used for OEM applications. The specifications below are common to both.
Specifications
| Housing | Plastic or titanium |
| Membrane | 0.5 mil- fast response, typical for profile applications 1 mil- slower response, typical for moored applications |
| Depth rating | 600 m (plastic) or 7000 m (titanium) 10500 m titanium housing available on request |
| Measurement range | 120% of surface saturation |
| Initial accuracy | 2% of saturation |
| Typical stability | 0.5% per 1000 h |
Further details can be found in the manufacturer's specification sheet.
Chelsea Technologies Minipack CTD-F
The Minipack CTD is a titanium/acetyl conductivity-temperature-depth system that can be used for discrete profiles, installed on a data buoy or on a towed undulator. The instrument includes conductivity, temperature, depth and fluorometer sensors, incorporating a high-performance 24-channel data logging and transmission system which allows for the acquisition of up to 16 external channels (e.g., dissolved oxygen, pH, PAR, fluorescence, turbidity, transmissance etc.).
Specifications
| Sensor | Type | Range | Accuracy | Resolution |
| Temperature | Pt resistance | -2 to 35 °C | 0.003 °C | 0.0005 °C |
| Conductivity | Induction cell | 0 to 70 mmho cm-1 | 0.005 mmho cm-1 | 0.001 mmho cm-1 |
| Pressure | Strain gauge with | 0 to 600 dbar | 0.2 dbar | 0.01 dbar |
Optical sensor specifications
| Chlorophyll a | Rhodamine | Amido Rhodamine | Fluorescein | Nephelometer | Phycoerythrin | Phycocyanin | |
| Excitation wavelengths | 430/30 nm or 470/30 nm | 470/30 nm | 425/30 nm | 480/80 nm | *470/30 nm | 530/30 nm | 590/35 nm |
| Emission wavelengths | 685/30 nm | 590/45 nm | 550/30 nm | 530/30 nm | *470/30 nm | 580/30 nm | 645/35 nm |
| Concentration range | 0.03 - 100 µg L-1 | 0.03 - 100 µg L-1 | 0.04 - 200 µg L-1 | 0.03 - 100 µg L-1 | *0.04 - 100 FTU | 0.03 - 100 µg L-1 | 0.03 - 100 µg L-1 |
| Resolution | 0.01 µg L-1 | 0.01 µg L-1 | 0.025 µg L-1 | 0.01 µg L-1 | *0.01 FTU | 0.01 µg L-1 | 0.01 µg L-1 |
*the wavelengths for the turbidity filters are a customer option but must be in the range 400 to 700 nm. The same wavelength is used in both the excitation path and the emission path.
Further details can be found in the manufacturer's specification sheet.
Turner Designs Cyclops-7 Submersible Sensors
The Cyclops-7 series of sensors is designed for integration into multi-parameter platforms, providing measurements of in vivo chlorophyll-a, cyanobacteria (phycocyanin and phycoerythrin), rhodamine and fluorescein dyes, optical brighteners, coloured dissolved organic matter (CDOM), crude oil and refined fuels, BTEX (benzene, toluene, ethylbenzene, and xylenes) or turbidity.
The voltage output of the sensor can be correlated with in situ concentration by calibration with a standard of known concentration. The excitation wavelength varies, depending on the environmental variable of interest, with visible wavelengths being used for chlorophyll, rhodamine, fluorescein and cyanobacteria; UV being used for CDOM, oil, optical brighteners and refined fuels; and IR being used for turbidity. The photodiode detector operates over the range 300-1100 nm. Custom optics over the range 260-900 nm are also available.
The Cyclops-7 operates over an ambient temperature range of 0 to 50°C and a water temperature range of -2 to 50°C. It has a depth rating of 600 m and displays a linearity of 0.99 R2 over the full range.
Specifications
| Application | Minimum detection limit | Dynamic range |
|---|---|---|
| Chlorophyll-a | 0.025 µg L-1 | 0 to 500 µg L-1 |
| CDOM | 0.4 ppb QS* | 0 to 2500 ppb QS* |
| Crude Oil | 0.02 ppb QS* | 0 to 1500 ppb QS* |
| Cyanobacteria | 150 cells mL-1 | 0 to 150000 cells mL-1 |
| Optical Brighteners | 1 ppb QS* | 0 to 15000 ppb QS* |
| Fluorescein Dye | 0.01 ppb | 0 to 500 ppb |
| Rhodamine Dye | 0.01 ppb | 0 to 1000 ppb |
| Turbidity | 0.05 NTU | 0 to 3000 NTU |
| Refined Fuels | 2 ppb NS** | 0 to 10000 ppb NS** |
| BTEX | 0.1 ppm | > 2500 ppm |
*QS - Quinine Sulphate
**NS - 1,5 Napthalene Disulfonic Disodium Salt
Further details can be found in the manufacturer's specification sheet.
Aanderaa Oxygen Optodes models 3835, 4130, 4175, 3830, 3930 and 3975
The Aanderaa Oxygen Optode is based on the ability of selected substances to act as dynamic fluorescence quenchers. The fluorescent indicator is a special platinum porphyrin complex embedded in a gas permeable foil that is exposed to the surrounding water.
A black optical isolation coating protects the complex from sunlight and fluorescent particles in the water. This sensing foil is attached to a window providing optical access for the measuring system from inside a watertight titanium housing.
The foil is excited by modulated blue light, and the phase of a returned red light is measured. By linearizing and temperature compensating, with an incorporated temperature sensor, the absolute O2 concentration can be determined. According to the manufacturer, the lifetime-based luminescence quenching principle offers the following advantages over electro-chemical sensors:
- Not stirring sensitive (it consumes no oxygen)
- Less affected by fouling
- Measures absolute oxygen concentrations without repeated calibrations
- Better long-term stability
- Less affected by pressure
- Pressure behaviour is predictable
- Faster response time
The 3835, 4130 and 4175 models are designed to operate down to 300 m, while there are two versions of the 3830, 3930 and 3975 models, designed to operate down to 2000 m and 6000 m, respectively. The sensors fit directly on to the top end-plate of Recording Current Meter RCM 9, and other Aanderaa instruments. Sensor specifications may be viewed via the following links: Aanderaa Oxygen Optodes 3835/4130/4175 and Aanderaa Oxygen Optodes 3830/3930/3975.
SeaSoar minipack CTD-f Instrument Description on RRS Discovery Cruise D321A
Instrument Description
The SeaSoar is a hydrodynamic fish towed behind the ship travelling at 8-9 knots linked by a faired cable. The usual cable length is 800m, which allows the fish to oscillate between the surface and a depth of 500m.
The unit has two stub wings whose angle of attack may be set by hydraulic servo motors. Thus the fish is able to climb or dive under the control of command signals from the ship or, more usually, by automatic command signals driven by the on-board pressure sensor. The wavelength and amplitude of the locus of the fish through the water depend upon the cable length, the ship's speed and the angle of attack selected for the wings.
The fish can carry a range of sensors. Invariably, a CTD is fitted but fluorometers, transmissometers, light sensors and plankton counters may also be included.
On this cruise, The 'C21' SeaSoar system (Allen et al., 2002), used for the first time on D253 (May/June 2001), carried a Chelsea Technologies Group (CTG) Minipack CTDF (Conductivity, Temperature, Depth and Fluorescence) instrument which was considerably more compact than CTD instruments traditionally carried by the SeaSoar vehicle. A substantial payload space was available in the SeaSoar for a multidisciplinary suite of additional instruments. Prior to RRS Discovery cruise D321, the SeaSoar vehicle had been prepared to carry the (NOC/Valeport) SUV-6 UV Nutrient Sensor, two oxygen sensors and four further fluorimetric pigment sensors.
The instrument was originally developed by the Institute of Oceanographic Sciences, Wormley (now the National Oceanography Centre) and was subsequently made available commercially.
Table of sensors
| Sensor | Serial Number | Last calibration date |
|---|---|---|
| Trimble 4000AX Global Positioning System receiver | unknown | unknown |
| Chelsea TG Minipack CTD-f | 210035 | 06/07/2007 |
| Turner Designs Cyclops-7 chlorophyll fluorometer | 2100432 | unknown |
| Turner Designs Cyclops-7 phycoerythrin cyanobacteria fluorometer | 2100594 | unknown |
| Turner Designs Cyclops-7 phycocyanin cyanobacteria fluorometer | 210043 | unknown |
| Turner Designs Cyclops-7 coloured dissolved organic matter fluorometer | 2100595 | unknown |
| Sea-Bird SBE 43 Dissolved Oxygen Sensor | 1196 | unknown |
| Aanderaa Oxygen Optode 3975 | 891 | 21/06/2007 |
| National Oceanography Centre Nitrate Sensor SUV6 | 2164 | unknown |
Project Information
Oceans 2025 Theme 9, Work Package 9.8: Development and maintenance of leading-edge ocean and coupled climate models - Next generation modelling methods for large scale ocean modelling and
This workpackage (WP) is being undertaken by the National Oceanography Centre, NOC. The finite-difference models currently in use internationally and operationally (e.g. at the Met. Office) retain the same structure as those in use 30 years ago, although making use of advanced modern parameterisations and codings. A meeting of the international modelling community in 1999 (New Ocean Model Creation Meeting at SOC) concluded that new methods were required to meet future demands of climate science. Future needs include a seamless junction between coastal and deep water models (long sought by POL and NOC) and a physically (and numerically) sensible 'nesting' of small detailed areas within larger models. The meeting identified the unstructured grid approach as being the key potential development, and particularly the use of model grids that can self-adapt.
A next generation ocean model (ICOM) of this type is being developed by The 'Pain consortium'. It is proposed in this WP to engage the NERC Centres (and university groups) at the earliest opportunity in scientific projects which exploit the capabilities of ICOM while simultaneously helping to improve the consortium's model.
More detailed information on this WP is available from page 14 of the official Oceans 2025 Theme 9 document: Oceans 2025 Theme 9
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/
Oceans 2025 Theme 1, Work Package 1.1: Recent Climate Change and the State of the Ocean
This Work Package is run by the National Oceanography Centre, Southampton (NOCS) and aims to accurately estimate recent and ongoing changes in the surface fluxes of heat, freshwater, and momentum, with a focus on the North Atlantic and the Atlantic sector of the Southern Ocean, and to relate these to the major changes in the observed ocean state.
NOCS will use observations and model output to determine the extent to which major changes in ocean properties over the last 50 years, particularly in the North Atlantic and Southern Ocean, are caused by changes in the air-sea fluxes of heat, freshwater and momentum. This work will build on previous experience of the development, evaluation and analysis of air-sea interaction datasets and make use of the next generation of ocean models developed under Oceans 2025 Theme 9.
More detailed information on this Work Package is available at pages 6 - 8 of the official Oceans 2025 Theme 1 document: Oceans 2025 Theme 1
Weblink: http://www.oceans2025.org/
Data Activity or Cruise Information
Cruise
| Cruise Name | D321 (D321A) |
| Departure Date | 2007-07-24 |
| Arrival Date | 2007-08-23 |
| Principal Scientist(s) | John T Allen (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 |
