Metadata Report for BODC Series Reference Number 2043695

• 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 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

IsoPrime100 Stable Isotope Ratio Mass Spectrometer

A gas-source laboratory benchtop isotope ratio mass spectrometer (IRMS), which operates in dual inlet or continuous flow modes. It forms part of the IsoPrime system which has a range of sample preparation and purification modules that can be coupled with the IsoPrime100 IRMS. The modules can analyse a range of samples (solids, liquids or gases) and each prepares the sample to be introduced into the IRMS as purified gases. The resultant prepared gases are then ionised and analysed for their isotopic content by the IRMS. The IsoPrime100 offers standard analysis of d13C, d18O, d15N and d34S using the IsoPrime Universal triple Collector (UTC), featuring patented high-performance Faraday buckets and automatic gain-switching. Due to its capacity to detect and measure up to ten ion beams simultaneously, the IsoPrime100 can also be used for multi-collector applications such as bromine isotopes, N2O isopromers, SO2-SO fractions and CO2 clumped isotopes, as well as other bespoke configurations. It has a sensitivity of 850 molecules per ion in dual inlet mode and 1200 molecules per ion in continuous flow mode.

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/IsoPrime100_Flyer.pdf

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.

Deployment

Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

RRS James Clark Ross JR17003 ORCHESTRA Salinity and d¹⁸O water samples

Originator's Protocol for Data Acquisition and Analysis

Water samples were collected from Niskin bottles on 59 of the 60 Conductivity-Temperature-Depth (CTD) casts on JR17003, and regularly from the underway uncontaminated seawater supply in the preparation lab. The sampling protocol used for the different activities was the same: salinity and d¹⁸O bottles were filled using the following standard procedures. The 200 ml glass salinity bottles were rinsed three times, then filled up to the base of the neck, dried with a clean paper and sealed with a plastic insert before a cap was screwed on. The 30 ml Nalgene wide-neck HDPE d¹⁸O bottles were rinsed three times, filled to the top, and the plastic lid screwed on as tightly as possible, leaving minimal headspace.

Salinity samples were analysed on board using a Guildline 8400B laboratory salinometer, calibrated against IAPSO P-series standard seawater (using approximately three standards per 48 samples).

The d¹⁸O analyses were performed on land at the NERC Isotope Geocsciences Laboratory (NIGL), British Geological Survey, Keyworth using the CO ₂ equilibrium method with an IsoPrime 100 mass spectrometer plus Aquaprep device. 243 samples (200 µl of water) were loaded into Labco Limited exetainers (3.7 ml) and placed in the heated sample tray at 40°C. The exetainers were then evacuated to remove atmosphere then flushed with CO ₂ and left to equilibrate for between 12 (first sample) to 37 (last sample) hours. Each individual gas sample was then admitted to the cryogenic water trap where any water vapour was removed. The dry sample gas was then expanded into the dual inlet where it was measured on the transducer before being expanded in the dual inlet bellows. Ionvantage software balanced the reference bellows relative to this volume. The sample and reference CO ₂ gases enter alternatively into the IsoPrime100 through the dual changeover valve for isotope ratio measurement. In each run two laboratory standards (CA-HI and CA-LO) plus up to two secondary standards were analysed in triplicate. The value of these laboratory standards has been accurately determined by comparison with international calibration and reference materials (VSMOW2, SLAP2 and GRESP (GRESP replaces GISP as of 2020)) and so the d ¹⁸O/d ¹⁶O ratios (versus VSMOW2) of the unknown samples can be calculated and are expressed in delta units, d ¹⁸O (parts per mille). Errors are < ± 0.05 per mille.

BODC Data Processing Procedures

The data were submitted to BODC in a single excel spreadsheet containing data from samples collected from the CTD. The metadata accompanying the data included: CTD station number, CTD cast number, Sample bottle number, Niskin bottle number, Depth (m), Latitude (°N), Longitude (°E), Date and Time (UTC).

Originator's variables were identified and mapped to BODC parameter codes and used for ingestion according to the table below

Quality control flags provided by the originator were mapped to BODC flags using the following mappings:

Project Information

Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA)

The Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) is a £8.4 million, five year (2016-2021) research programme funded by the Natural Environment Research Council (NERC). The aim of the research is to to advance the understanding of, and capability to predict, the Southern Ocean's impact on climate change via its uptake and storage of heat and carbon. The programme will significantly reduce uncertainties concerning how this uptake and storage by the ocean influences global climate, by conducting a series of unique fieldwork campaigns and innovative model developments.

Background

ORCHESTRA represents the first fully-unified activity by NERC institutes to address these challenges, and will draw in national and international partners to provide community coherence, and to build a legacy in knowledge and capability that will transcend the timescale of the programme itself.

It brings together science teams from six UK research institutions to investigate the role that the Southern Ocean plays in our changing climate and atmospheric carbon draw-down. It is led by British Antarctic Survey, in partnership with National Oceanography Centre, British Geological Survey, Plymouth Marine Laboratory, the Centre for Polar Observation and Modelling and the Sea Mammal Research Unit.

The oceans around Antarctica play a critical a key role in drawing down and storing large amounts of carbon and vast quantities of heat from from the atmosphere. Due to its remoteness and harsh environment, the Southern Ocean is the world's biggest data desert, and one of the hardest places to get right in climate models. The ORCHESTRA programme will make unique and important new measurements in the Southern Ocean using a range of techniques, including use of the world-class UK research vessel fleet, and deployments of innovative underwater robots. The new understanding obtained will guide key improvements to the current generation of computer models, and will enhance greatly our ability to predict climate into the future.

The scope of the programme includes interaction of the Southern Ocean with the atmosphere, exchange between the upper ocean mixed layer and the interior and exchange between the Southern Ocean and the global ocean.

Further details are available on the ORCHESTRA page.

Participants

Six different organisations are directly involved in research for ORCHESTRA. These institutions are:

• British Antarctic Survey (BAS)
• National Oceanography Centre (NOC)
• Plymouth Marine Laboratory (PML)
• British Geological Survey (BGS)
• Centre for Polar Observation and Modelling (CPOM)
• Sea Mammal Research Unit (SMRU)

GO-SHIP are a third party organisation that, although not directly involved with the programme, will conduct ship based observations that will also be used by ORCHESTRA.

Research details

Three Work Packages have been funded by the ORCHESTRA programme. These are described in brief below:

• Work Package 1: Interaction of the Southern ocean with the atmosphere
  WP1 will use new observations of surface fluxes and their controlling parameters in order to better constrain the exchanges of heat and carbon loss across the surface of the Southern Ocean.

• Work Package 2: Exchange between the upper ocean mixed layer and the interior.
  This work package will combine observationally-derived data and model simulations to determine and understand the exchanges between the ocean mixed layer and its interior.

• Work Package 3: Exchange between the Southern Ocean and the global ocean .
  This WP will use budget analyses of the hydrographic/tracer sections to diagnose the three-dimensional velocity field of the waters entering, leaving and recirculating within the Southern Atlantic sector of the Southern ocean.

• Fieldwork and data collection

  The campaign consists of 12 core cruises on board the NERC research vessels RRS James Clark Ross and RRS James Cook and will include hydrographic/tracer sections conducted across Drake Passage (SR1b), the northern Weddell Sea/Scotia Sea (A23), the northern rim of the Weddell Gyre (ANDREXII) and across the South Atlantic (24S). Section I6S will be performed by GO-SHIP Project Partners. Measurements will include temperature, salinity, dissolved oxygen, velocity, dissolved inorganic carbon, total alkalinity, inorganic nutrients, oxygen and carbon isotopes, and underway meteorological and surface ocean observations including pCO₂.

  Tags will be deployed on 30 Weddel seals and these will provide temperature and salinity profiles that can be used alongside the Argo data.

  Autonomous underwater ocean gliders will conduct multi-month missions and will deliver data on ocean stratification, heat content, mixed layer depth and turbulent mixing over the upper 1 km, with previously-unobtainable temporal resolution. These gliders will be deployed in the Weddell Gyre and the ACC.

  Field campaigns with the MASIN meteorological aircrafts will be conducted flying out of Rothera and Halley research stations and the Falkland Islands. These campaigns will deliver information on key variables relating to air-sea fluxes (surface and air temperature, wind, humidity, atmospheric CO₂, radiation, turbulent fluxes of heat, momentum and CO₂), in different sea ice conditions and oceanic regimes.

  Eart Observation datasets will be used to inform the programme on the properties of the ocean, sea ice and atmosphere and on interactions between them.

  A cluster of 6 deep ocean moorings in the Orkney Passage will collect year round series of AABW temperatre and transport. This work connects to the NERC funded project Dynamics of the Orkney Passage Outflow (DYNOPO).

  The UK Earth System model (UKESM) and underlying physical model will be used to conduct analyses of heat and carbon uptake and transport by the Southern Ocean and their links to wider climate on decadal timescales.

  An eddy-resolving (1/12°) sector model of the ocean south of 30°S with 75 vertical levels, will be built using the NEMO model coupled to the Los Alamos sea ice (CICE) model. The improvements on the ocean boundary layer will be based from the results from the NERC-funded OSMOSIS project and the inclusion of tides.

  20-5 year runs of an adjoint model will be conducted to determine how key forcings and model states affect the uptake and subduction of heat and carbon by the ocean.

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JR17003_CTD_CTD055

Please note:the supplied parameters may not have been sampled from all the bottle firings described in the table above. Cross-match the Sample Reference Number above against the SAMPRFNM value in the data file to identify the relevant metadata.

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: