Metadata Report for BODC Series Reference Number 2053339

• 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.

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.

Nutrient concentrations from CTD samples for Cruise DY096

Originator's Protocol for Data Acquisition and Analysis

Inorganic nutrients DY096 Seawater samples for macronutrient analyses were collected unfiltered directly from the titanium rosette after the TA/DIC into pre- labelled sterile 50 ml centrifuge tubes (rinsed three times with water from the same Niskin) and frozen (-20° C) onboard the RRS Discovery for future analyses at the National Oceanography Centre. The samples were analysed using standard gas-segmented flow spectrophotometric techniques (Hydes et al., 2010).

A 4-channel Seal Analytical (QuAAtro 39) segmented flow-analyser with XY autosampler was used for the analysis of micro-molar concentrations of dissolved inorganic nutrients (silicate, phosphate, nitrate plus nitrite and nitrite). Seal Analytical chemistry and cleaning procedure protocols used for the analyses of DY096 sample were:

1. Silicate in seawater method No. Q-066-05 Rev. 5

2. Phosphate in water method No. Q-064-05 Rev. 8

3. Nitrate and nitrite in seawater method No. Q-068-05 Rev.11

4. Nitrite in seawater method No. Q-070-05 Rev. 6

Nitrate was calculated by correcting for nitrite as per standard autoanalyser method.

Back at NOC samples were defrosted overnight in the fridge and shaken to ensure a homogenous sample. Samples collected from the CTD were measured from the lowest to the highest concentration (surface to deep) to reduce carry over effects. Milli-Q water was used for the baseline and wash solution.

Instrument Description

SEAL Analytical QuAAtro Autoanalyser

DY096 Cruise report

Further information can be found in the DY096 Cruise report.

BODC Data Processing Procedures

Data were submitted in an .xlsx spreadsheet containing dissolved nutrient sample measurements of silicate, nitrate, phosphate, nitrite, total nitrogen and total phosphorus. Additional metadata such as station, position, date, time, CTD cast number, CTD bottle number 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 originator carried out the following data quality performance checks:

In order to test the accuracy and precision of the analyses, CRMs from The General Environmental Technos Co., Ltd., (KANSO) were measured in triplicates at the start and end of every run. For the analyses of DY096 samples KANSO CRMs lot CD, CJ and CB were used.

CTD data was plotted against historical data mainly GLODAP 2 and de Baar 1999. There were six clear outliers;

Station 2 : two suspect points bottle 4 (748db) and bottle 6 (498 db)

Station 3 : one suspect point bottle 6 (497db)

Station 5 : three suspect points bottle 10 (179 db), bottle 14 (100 db) and bottle 20 (41 db)

BODC performed quality control checks on the data. Any originator flags were mapped to standard BODC flags. Any data values which were below the detection limit of the instrument were applied a '<' flag.

References

Hydes D. J., Aoyama M., Aminot A., Bakker K., Becker S., Coverly S., Daniel A., Dickson A. G., Grosso O., Keroue R., van Ooijen J., Sato K., Tanhua T., Woodward E. M. S., Zhang J. Z. (2010). Determination of dissolved nutrients (N, P, Si) in seawater with high precision and inter-comparability using gas-segmented continuous flow analysers. The GO-SHIP Repeat Hydrography Manual : A Collection of Expert Reports and guidelines. IOCCP Report No 14, ICPO Publication Series No. 134, version 1, 2010.

de Baar, H.J.W., de Jong, J.T.M., Nolting, R.F., Timmermans, K.R., van Leeuwe, M.A., Bathmann, U., van der Loeff, M.R., Sildam, J., 1999. Low dissolved Fe and the absence of diatom blooms in remote Pacific waters of the Southern Ocean. Mar. Chem. 66, 1-34. http://dx.doi.org/10.1016/S0304-4203(99)00022-5

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 DY096_UCCTD_DY096_CTD02

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.

Related Data Activity activities are detailed in Appendix 1

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 2

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: DY096_UCCTD_DY096_CTD02

Related series for this Data Activity 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.

Appendix 2: 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.