Metadata Report for BODC Series Reference Number 2053886

• Metadata Summary

• Problem Reports

• Data Access Policy

• Data 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

Carbon Uptake and Seasonal Traits of Antarctic Remineralisation Depth (CUSTARD) data access

Access to these data is currently restricted to the consortium Principal Investigators and consortium co-workers. Anyone granted permission to use the data during this period of restriction must acknowledge the data originator on any resulting papers.

Data Policy

Carbon Uptake and Seasonal Traits of Antarctic Remineralisation Depth (CUSTARD) Data Policy

The following data policy has been approved by the Principal Investigator and applies to all datasets received under the CUSTARD project.

Designated Data Centres

Data arising from the project are lodged with the British Oceanographic Data Centre (BODC) or the UK Polar Data Centre (UK PDC) on acquisition, together with such metadata as are defined under the NERC data policy.

BODC - Physical and chemical oceanography data are held at BODC. This includes data from CTD, data from the ship's fixed sensors, gliders, mooring, Red Camera Frame, Marine Snow Catcher (MSC), Underwater Vision Profile (UVP), incubation experiments, etc.

PDC - Biological oceanography data are submitted to BODC, but held at and disseminated by PDC. This includes plankton biomass and microscopy data.

Embargo & Open Access

Two dataset types are each subject to one-year embargo, and are thus made public no earlier than January 2021:

• Nitrate and silicate data measured from the NOC lab-on-chip sensors mounted on the Ocean Observatories Initiative (OOI) mooring. The embargo will start from the time of processed data submission to BODC, and end 12 months later.
• All data collected by the Slocum gliders (MARS and Rutgers). The embargo will start from the date of the latest glider recovery, and end 12 months later.

Beyond the embargo expiry date, the data are openly provided by the data centres under the Natural Environment Research Council (NERC) Open Data policy.

All other datasets are freely accessible as soon as they are available under the same NERC policy.

The following attribution statement must always be used to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council".

Narrative Documents

SEAL Analytical QuAAtro colorimetric autoanalyser

The SEAL QuAAtro high Performance Microflow Analyzer is the latest generation of the original world-class Technicon^TM Segmented Flow Analysis (SFA) systems.

A basic SFA system consists of an autosampler, a peristaltic pump, a chemistry manifold, a detector and data acquisition software. Sample and reagents are pumped continuously through the chemistry manifold. Air bubbles are introduced at regular intervals forming unique reaction segments which are mixed using glass coils. Glass is ideal, as it is inert, stays clean and enables easy visual checks.

In SFA, reactions run to completion and the ratio of sample to reagents in the detector reaches a constant maximum value. This results in ultra-low detection limits and exceptional reproducibility. Variations in reaction time, temperature and sample matrix do not affect the results as they do in other colorimetric techniques, such as flow injection analysis, where the reaction is not brought to completion.

QuAAtro is a microflow SFA system, the internal diameter of all glassware being 1 mm. This reduces reagent consumption and increases throughput, with most methods running at 100 - 120 samples hour. The integrated enclosed manifold and detector are heated to 37 °C. Flow stability is ensured as the optimal bubble frequency for each method is programmed by silent air valves. Automatic start-up, method changeover and shutdown allows true unattended operation and overnight running. QuAAtro checks its own performance, with automatic monitoring of noise, drift, bubble pattern and light energy, before and during a run.

Up to four methods can run at the same time on one console, and there is a special 5-channel version for nutrients in seawater. Two consoles can be combined to give an 8-channel system.

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

GO-FLO Bottle

A water sampling bottle featuring close-open-close operation. The bottle opens automatically at approximately 10 metres and flushes until closed. Sampling with these bottles avoids contamination at the surface, internal spring contamination, loss of sample on deck and exchange of water from different depths.

There are several sizes available, from 1.7 to 100 litres and are made of PVC with a depth rating of up to 500 m. These bottles can be attached to a rosette or placed on a cable at selected positions.

Nutrient concentrations from CTD samples for Cruise DY112

Originator's Protocol for Data Acquisition and Analysis

During DY112 seawater samples were analysed for the determination of inorganic nutrient concentrations. The analyses were for nitrate and nitrite (NO³+NO²), silicate (SiO²), nitrite (NO²) and phosphate (PO⁴). The water samples were drawn from the Go-Flo bottles into pre-labelled 15ml centrifuge tubes. Each tube was rinsed three times with the same water as the sample was taken from and then filled to 10-15 ml marks.

Analysis was within 24 hours of the samples being taken and on a QuAAtro 39 segmented flow autoanalyser linked to a XY-2 Sampler, both by SEAL Analytical UK Ltd, and controlled via a DELL Latitude laptop using the appropriate software package supplied by SEAL, called AACE 7.09. The chemistry methods used were also supplied by SEAL (also specified in CUSTARD DY111 cruise report). During runs ultra-pure water (MilliQ) was used as a wash, to provide the baseline and was also the matrix that the stock calibrant solutions were made up in. Artificial seawater solution was used to prepare a range of calibration standard solutions (also specified in CUSTARD DY111 cruise report). The efficiency of the reduction from NO³ to NO² by the cadmium coil was calculated by comparing a single NO² standard against a single NO3 standard (10 µmol/L each). Two sets of certified reference materials (CRM Lots CJ and CB, KANSO, Japan) were measured at a start and the end of each sample run. These values were then used to calculate random and systematic uncertainties of each measurement, following Birchill et al. 2019. The detection limit was calculated from 10 replicates of the lowest concentration standard for each run. The baseline (or offset) of the wash solution was always set at 5% of the chart window. The actual absorbance values for the baseline were recorded before starting each run to give an indication of stability of the wash solution and/or cleanliness of the system. The gain was set by running the highest sample through the system and selecting 'set gain' in the software. The chart window was then automatically adjusted so that the top standard peak sits at the 90% point.

Instrument Description

SEAL Analytical QuAAtro Autoanalyser

BODC Data Processing Procedures

Data were submitted in an .csv spreadsheet containing dissolved nutrient sample measurements of silicate, nitrate + nitrite, phosphate and nitrite data with their associated standard deviations. Additional metadata such as station, position, date, time, and depth (m) were also included in the file. The data were reformatted and assigned BODC parameter codes. Quality control checks were made and BODC applied flags were applicable. The data were then loaded into the BODC database using established BODC data banking procedures.

A parameter mapping table is provided below:

Data Quality Report

The correlation coefficient for all chemistries during all runs was higher than 0.9990. The efficiency of Cd column never dropped below 100%. The detection limit (LoD) is reported for individual analysis run. LoD describes the lowest concentration which can be reliably reported as a non-zero value. Here, the LoD is defined as the standard deviation of multiple measurements of a near-zero sample (lowest calibration standard) multiplied by a factor between 2.3 and 3.1 depending on the number of measurements (see procedure described in US EPA document Pt. 136 App. B for 'Method Detection Limit'). Depending on a analysis run, the detection limits for each parameter ranged as follows: 0.02-0.2 µmol/L for Nitrate+Nitrite, 0.02-0.15 µmol/L for Silicate, 0.01-0.033 µmol/L for Nitrite, and 0.002-0.019 µmol/L for Phosphate.

References

Birchill A.J., Clinton-Bailey G., Hanz R., Mawji E., Cariou T., White C., Ussher S.J., Worsfold P.J., Achterberg E.P., Mowlem M., (2019) Realistic measurement uncertainties for marine macronutrient measurements conducted using gas segmented flow and Lab-on-Chip techniques, Talanta, Volume 200, 2019, Pages 228-235, ISSN 0039-9140, https://doi.org/10.1016/j.talanta.2019.03.032.

Project Information

Carbon Uptake and Seasonal Traits of Antarctic Remineralisation Depth (CUSTARD)

Carbon Uptake and Seasonal Traits of Antarctic Remineralisation Depth (CUSTARD) is a £1.8 million, four-year (2018-2022) research project funded by the Natural Environment Research Council (NERC).

The main aim of the CUSTARD project is to quantify the seasonal drivers of carbon fluxes in a region of the Southern Ocean upper limb, and estimate how long different quantities of carbon are kept out of the atmosphere based on the water flow routes at the observed remineralisation depths. Please visit the CUSTARD web page for more information

CUSTARD is one of three projects funded as part of the Role of the Southern Ocean in the Earth System (RoSES) programme, also known as the Southern Ocean programme. Please see the RoSES project document for more information on the wider programme and the research projects associated with it.

Background

The upper limb of the Antarctic Circumpolar Current (ACC) represents an important junction in the marine carbon cycle, as the fate of carbon fixed by surface phytoplankton will differ according to how deep it penetrates before being remineralised. If shallow remineralisation occurs, carbon will follow the upper limb circulation and upwell further north, escaping into the atmosphere within decades. On the other hand, deep remineralisation will result in carbon entering the lower limb circulation, with the potential of being retained in the ocean for hundreds of years. Seasonality in plankton dynamics play an important role in remineralisation depth, and CUSTARD aims to resolve all factors contributing to the carbon export out of the region.

Participants

Six different UK-based organisations are directly involved in research for CUSTARD:

• National Oceanography Centre (NOC)
• NERC British Antarctic Survey (BAS)
• University of Southampton
• University of Oxford
• Plymouth University
• University of East Anglia (UEA)

CUSTARD collaborates closely with the US Ocean Observatories Initiative (OOI) program through sharing of instruments and platforms at and around the Global Southern Ocean Array. OOI is funded by the National Science Foundation (NSF) and is managed by the Woods Hole Oceanographic Institution. Rutgers University maintains the cyberinfrastructure component, working alongside CUSTARD scientists in the handling and distribution of shared observational data.

Research details

Four Work Packages have been funded by the CUSTARD project, each addressing a separate project objective within the region of study in the south eastern Pacific ocean. These are described briefly below:

• Work Package 1: Obtain an accurate picture of the seasonal air-sea flux and macronutrient drawdown.
  This work package aims at determining the magnitude and variability of air-sea CO2 fluxes and their physical and biogeochemical drivers. High-resolution carbon measurements in the water column, CO2 flux estimates and daily resolved nitrate and silicate observations are combined to better understand the link between seasonal changes in CO2 fluxes and biological variability.

• Work Package 2: Quantify the link between iron and silicate availability and remineralisation depth.
  This work package investigates the annual cycle of phytoplankton dynamics, net production and export of organic material in conjunction with iron availability.

• Work Package 3: Observationally determine the seasonal cycle in remineralisation depth.
  This work package assesses remineralisation depth and its variability using marine snow catchers deployed during the process cruise, and backscatter measurements carried out year-round by gliders.

• Work Package 4: Examine the link between seasonality and remineralisation depth and the trajectory of carbon from the surface out of the upper limb.
  This work package aims to ingest all CUSTARD observational data into models to determine whether seasonal variability in phytoplankton composition is reflected in changes in remineralisation depth, which in turn leads to seasonal variability in the fate of organic carbon leaving the Southern Ocean via the upper limb.

Fieldwork and data collection

All the observational data from the project is collected at and south of the Ocean Observatories Initiative (OOI) Global Southern Ocean Array, located south-west of Chile. Data collection activities span from November 2018 to January 2020, and include three cruises, four glider missions, and one mooring.

Cruises

All cruises depart from and return to Punta Arenas (Chile). Cruise activities include deployments and recovery of gliders and a mooring, Conductivity, Temperature and Depth (CTD), trace metal clean GoFlo bottle sampling, Red Camera Frame, Marine Snow Catcher and Underwater Vision Profiler deployments, as well as laboratory incubations with sea water samples. See cruise details below:

Gliders

Two Slocum 1000 MARS gliders (Pancake and Churchill) are deployed from DY096, to collect data continuously for one year until recovery on DY111. The gliders are mounted with CTD sensors, an optode, a fluorometer, and twin backscatter sensors. Pancake failed and its mission ended early in February 2019.

One Rutgers University glider is deployed from DY111, to collect data until recovery at the end of the same cruise. The glider is owned by Rutgers University and the data is shared with CUSTARD. It carries CTD sensors, an optode, a fluorometer, a backscatter sensor and a particle size analyser.

Mooring

Deployment of Global Surface Mooring GS01SUMO-00004 (SUMO-4) during DY096, to take continuous measurements for approximately one year until recovery during DY112. Its location is roughly 54 28 S, 89 02 W. This is an OOI mooring provided and deployed by WHOI, and adapted to integrate NOC lab-on-chip nitrate and silicate sensors.

Contacts

Dr. Adrian Marin (National Oceanography Centre, UK) - Lead Principal Investigator and lead of Work Package 4
Dr. Dorothee Bakker (University of East Anglia, UK) - Lead of Work Package 1
Prof. Mark Moore (University of Southampton, UK) - Lead of Work Package 2
Dr. Stephanie Henson (National Oceanography Centre / University of Southampton, UK) - Lead of Work Package 3

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for DY112_BOTTLE_GF1

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

Fixed Station Information

Fixed Station - Ocean Observatories Initiative (OOI) Global Southern Ocean Array

OOI Southern Ocean Array is an offshore site situated in the South Pacific to the south west of Chile, in an area of large scale thermohaline circulation, intermediate water formation, and CO₂ sequestration. The array originally comprised four moorings and a combination of Open Ocean and Profiling Gliders. All of the moorings were successfully recovered for the last time in January 2020.

The following is a list of the cruises involved in recovery and deployment of the moorings:

More information can be found at: https://oceanobservatories.org/array/global-southern-ocean-array/

Related Fixed Station activities are detailed in Appendix 1

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:

Appendix 1: OOI-Southern Ocean

Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.