Metadata Report for BODC Series Reference Number 1039778

• 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

Problem Reports

No Problem Report Found in the Database

Data Quality Report

Transmittance

Values recorded by the transmissometer regularly exceeded 100%. The data originator acknowledged these values and explained that they were probably due to the transmissometer being slightly out of calibration. All values exceeding 100% have been flagged.

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

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

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

JR20100613 (JR219) CTD Instrumentation (casts 1-12 & 33-100)

CTD unit and auxiliary sensors

The CTD system used for casts 1-12 and 33-100 was the Sea-Bird 911 plus. This was mounted on a stainless steel rosette frame, equipped with 24 10-litre Niskin bottles. The CTD was fitted with the following scientific sensors:

The salinity samples from the CTD were analysed during the cruise in a constant temperature laboratory using the Guildline Autosal model 8400B.

Sea-Bird Electronics SBE 911 and SBE 917 series CTD profilers

The SBE 911 and SBE 917 series of conductivity-temperature-depth (CTD) units are used to collect hydrographic profiles, including temperature, conductivity and pressure as standard. Each profiler consists of an underwater unit and deck unit or SEARAM. Auxiliary sensors, such as fluorometers, dissolved oxygen sensors and transmissometers, and carousel water samplers are commonly added to the underwater unit.

Underwater unit

The CTD underwater unit (SBE 9 or SBE 9 plus) comprises a protective cage (usually with a carousel water sampler), including a main pressure housing containing power supplies, acquisition electronics, telemetry circuitry, and a suite of modular sensors. The original SBE 9 incorporated Sea-Bird's standard modular SBE 3 temperature sensor and SBE 4 conductivity sensor, and a Paroscientific Digiquartz pressure sensor. The conductivity cell was connected to a pump-fed plastic tubing circuit that could include auxiliary sensors. Each SBE 9 unit was custom built to individual specification. The SBE 9 was replaced in 1997 by an off-the-shelf version, termed the SBE 9 plus, that incorporated the SBE 3 plus (or SBE 3P) temperature sensor, SBE 4C conductivity sensor and a Paroscientific Digiquartz pressure sensor. Sensors could be connected to a pump-fed plastic tubing circuit or stand-alone.

Temperature, conductivity and pressure sensors

The conductivity, temperature, and pressure sensors supplied with Sea-Bird CTD systems have outputs in the form of variable frequencies, which are measured using high-speed parallel counters. The resulting count totals are converted to numeric representations of the original frequencies, which bear a direct relationship to temperature, conductivity or pressure. Sampling frequencies for these sensors are typically set at 24 Hz.

The temperature sensing element is a glass-coated thermistor bead, pressure-protected inside a stainless steel tube, while the conductivity sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Thermistor resistance or conductivity cell resistance, respectively, is the controlling element in an optimized Wien Bridge oscillator circuit, which produces a frequency output that can be converted to a temperature or conductivity reading. These sensors are available with depth ratings of 6800 m (aluminium housing) or 10500 m (titanium housing). The Paroscientific Digiquartz pressure sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.

Additional sensors

Optional sensors for dissolved oxygen, pH, light transmission, fluorescence and others do not require the very high levels of resolution needed in the primary CTD channels, nor do these sensors generally offer variable frequency outputs. Accordingly, signals from the auxiliary sensors are acquired using a conventional voltage-input multiplexed A/D converter (optional). Some Sea-Bird CTDs use a strain gauge pressure sensor (Senso-Metrics) in which case their pressure output data is in the same form as that from the auxiliary sensors as described above.

Deck unit or SEARAM

Each underwater unit is connected to a power supply and data logging system: the SBE 11 (or SBE 11 plus) deck unit allows real-time interfacing between the deck and the underwater unit via a conductive wire, while the submersible SBE 17 (or SBE 17 plus) SEARAM plugs directly into the underwater unit and data are downloaded on recovery of the CTD. The combination of SBE 9 and SBE 17 or SBE 11 are termed SBE 917 or SBE 911, respectively, while the combinations of SBE 9 plus and SBE 17 plus or SBE 11 plus are termed SBE 917 plus or SBE 911 plus.

Specifications

Specifications for the SBE 9 plus underwater unit are listed below:

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

Aquatracka fluorometer

The Chelsea Instruments Aquatracka is a logarithmic response fluorometer. It uses a pulsed (5.5 Hz) xenon light source discharging between 320 and 800 nm through a blue filter with a peak transmission of 420 nm and a bandwidth at half maximum of 100 nm. A red filter with sharp cut off, 10% transmission at 664 nm and 678 nm, is used to pass chlorophyll-a fluorescence to the sample photodiode.

The instrument may be deployed either in a through-flow tank, on a CTD frame or moored with a data logging package.

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

WETLabs C-Star transmissometer

This instrument is designed to measure beam transmittance by submersion or with an optional flow tube for pumped applications. It can be used in profiles, moorings or as part of an underway system.

Two models are available, a 25 cm pathlength, which can be built in aluminum or co-polymer, and a 10 cm pathlength with a plastic housing. Both have an analog output, but a digital model is also available.

This instrument has been updated to provide a high resolution RS232 data output, while maintaining the same design and characteristics.

Specifications

Further details are available in the manufacturer's specification sheet or user guide.

JR20100613 (JR219) CTD Originator Processing

Sampling Strategy

A total of 97 CTD casts were performed during the cruise which sailed from Immingham (UK) to Longyearbyen (Svalbard) in the Arctic, before returning to Peterhead (UK). Two CTD packages were used during the cruise, both housed in a stainless steel frame equipped with dual temperature and conductivity sensors. The first CTD carousel was fitted with twenty-four 10 litre Niskin bottles and was deployed from the CTD winch on the starboard side of the ship for casts 1-12 and 33-100. The second CTD carried twelve 10 litre Niskin bottles and was deployed from the stern of the ship for casts 13-32 of the cruise due to ice conditions.

It should be noted that the data originator has labeled the CTD events that occurred during the cruise as CTD001-CTD100. CTD021 and CTD053 refer to the upcasts from the preceding casts, so the complete CTD deployments will be referred to as CTD020 and CTD052 by BODC. Likewise CTD034 refers to the upcast from bottle 13 to 24 following on from CTD033, and the complete deployment will be referred to as CTD033 by BODC.

Data Processing

Following the completion of each CTD cast the data were saved to the deck unit PC and transferred over the network to a Unix data disk. Sea-Bird Data Processing V 7.18b software was used to perform all processing steps.

Raw data files were converted to engineering units and binary .CNV files using the DATCNV program. Sea-Bird bottle data files (.BTL), with information on pressure and other readings logged at the time of bottle firing, were also generated during the data conversion process. The WILDEDIT program was run to remove any large pressure spikes and then the SeaSoft program ALIGNCTD was run to advance the oxygen measurements by 5 seconds ensuring the calculations of dissolved oxygen concentration are made using measurements from the same parcel of water. In addition the secondary conductivity was advanced by 0.073 seconds, as recommended by Sea-Bird. CELLTM was run, according to Sea-Bird's recommendations, to remove conductivity cell thermal mass effects from the measured conductivity and FILTER was run on the pressure channel using a low-pass filter value of 0.15 to smooth the rapidly changing data. Finally twin salinities, twin density and depth were calculated using the DERIVE program and TRANSLATE wrote the data to an ASCII output .CNV file. Despiking of the pressure, oxygen, temperature and salinity data was carried out by visualising the data in MATLAB. If a spike occurs in pressure, temperature or salinity the whole corresponding scan is deleted. If the spike occurs in the other channels, the value is set to NaN and all remaining channels are left unedited. Following despiking of the data in MATLAB the module BINAVERAGE averaged the 24 Hz data into 2db-bins, using the downcast data only.

It should be noted that the dual temperature and conductivity measurements were in good agreement throughout the cruise, except for the beginning of the sea ice deployments, which occurred between casts 13-32. The secondary conductivity sensor also appeared to be faulty and was replaced after a few casts but secondary conductivity, salinity and density have not been included in the final 2db version of the dataset, which only contains data from the preferred primary temperature and conductivity sensor pairing.

Calibrations

Throughout the cruise the CTD was sampled for salinity in order to calibrate the conductivity sensors. Salinity was measured using a Guildline Autosal8400 in a temperature controlled room onboard the ship.

In total, 90 discrete salinity samples were collected using the first CTD package (casts 1-12 and 33-100). Discrete salinities were compared with corresponding salinities derived from the Sea-Bird sensors. Six data points had a difference greater than 0.1 PSU and were discarded, otherwise agreement between the Autosal and Sea-Bird values was good.

The following calibrations were produced;

• Sal1_calibrated = 0.9956 Sal1_uncalibrated + 0.1582
• Sal2_calibrated = 0.9957 Sal2_uncalibrated + 0.1664

For the second CTD deployed from casts 13-32, 25 samples were collected and analysed. The correlation was not as strong as for the first CTD. This can probably be attributed to the CTDs taking place while the ship was moored in the ice floe, in highly stratified waters, often with the propellers running to clear ice drifting at the stern. 5 data points had a difference greater than 0.2 psu and were not used for the calibration.

The following calibrations were produced;

• Sal1_calibrated = 0.9454 Sal1_uncalibrated + 1.9182
• Sal2_calibrated = 0.9460 Sal2_uncalibrated + 1.9012

The oxygen data were later calibrated against discrete oxygen measurements collected from CTD casts throughout the cruise, producing the following equations;

First CTD - Casts 1-12 and 33-100

• Ox_calibrated = 1.0042 Ox_uncalibrated + 0.0935 (units: mg l^-1)

Second CTD - Casts 13-32

• Ox_calibrated = 0.8222 Ox_uncalibrated + 2.9101 (units: mg l^-1)

References

Dumont, E., 2010. CTD Report. Scottish Association for Marine Science.

Available - CTD Report

JR20100613 (JR219) CTD Processing undertaken by BODC (casts 1-12 & 33-100)

Data arrived at BODC in a total of 78 ASCII, WHPO standard files representing the CTD casts deployed on the primary frame during cruise JR20100613 (JR219). These files contain 2db-bin averaged data including temperature and salinity, from the primary temperature and conductivity sensors, and dissolved oxygen channels processed to WOCE standards alongside concurrent fluorometer and transmissometer data.

Additional 24 Hz ASCII files containing data sampled at their original density were also supplied to BODC. These files contain some additional parameters compared to the 2db-bin averaged data files, including data from secondary temperature and salinity sensors, but due to having fewer quality control procedures applied these data have not undergone any further BODC processing. They have however been archived at BODC in their original format and are available upon request.

The lodged WHPO standard casts were reformatted to BODC's internal format, a netCDF subset. The following table shows the mapping of variables within the ASCII files to appropriate BODC parameter codes:

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

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 1.6: The Effect of Climate Change on the Arctic marine system

This Work Package is run by the Scottish Association for Marine Science (SAMS). Observational and experimental studies will be undertaken in ice-covered and open waters of the western Barents Sea and the northern Svalbard region for which understanding of the physical oceanography is relatively well advanced, and where seasonal access via a UK ice-strength research vessel (RRS James Clark Ross) and installation of year-round in situ instrumentation are feasible.

These studies will complement previous observational and experimental studies undertaken in the western/central Barents Sea (Wassmann, 2002) and will be used, along with published data sets and remotely-sensed data, to parameterise and test a coupled physical-biological model, which will be developed in collaboration with the Proudman Oceanographic Laboratory (POL), in the UK. This model will allow comparison with similar modelling studies undertaken in Arctic waters, including the western/central Barents Sea (Wassman et al., 2006); it will also advance the current state of the art by improved parameterisation of microbial rate processes, and by the incorporation of benthic and sea-ice biogeochemical processes and feedbacks.

This approach, encompassing ship, instrument and modelling platforms, will provide the UK with an enhanced strategic capability to undertake, and be informed by, research on the consequences of rapid climate change in the Arctic.

More detailed information on this Work Package is available at pages 17 - 19 of the official Oceans 2025 Theme 1 document: Oceans 2025 Theme 1

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

References:

Wassmann P., 2002. Seasonal C-cycling variability in the open ocean and ice-covered waters of the Barents Sea: an introduction, J Mar Syst, 38, 1-7

Wassmann P., Slagstad D., Wexels Riser C., and Reigstad M., 2006. Modelling the ecosystem dynamics of the Barents Sea including the marginal ice zone, II Carbon flux and interannual variability, J Mar Syst, 59, 1-24

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

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:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle: