Metadata Report for BODC Series Reference Number 2244129

• 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

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

Metrohm 916 Ti-Touch compact potentiometric titrator

The Metrohm 916 Ti-Touch is a stand-alone potentiometric titrator for dynamic (DET), monotonic (MET), set endpoint (SET) and manual titrations (MAT). The instrument consists of an intergrated buret, rod stirrer (or magnetic stirrer) and dosing system with a live touch control display.

Specifications

More information can be found in the manufacturer's product description.

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.

GoFlo Bottle Dissolved Oxygen (DO) for CUSTARD Cruise DY112

Originator's Protocol for Data Acquisition and Analysis

Sampling methodology

The RRS Discovery cruise DY112 departed Punta Arenas, Chile on 16 January 2020 and returned to Punta Arenas, Chile on 25 January 2020.

Sampling occurred on 21 January 2020 between 12:22 - 17:20. Two profiles of Go-Flo bottles on Kevlar rope were lowered to each respective depth from deepest (150 m) to shallowest (10 m) (nominal depths sampled: 150 m, 100 m, 50 m, 10 m) and fired using a messenger. Each depth was sampled using a single bottle, with water taken before the bottle was sent back over to the next depth. Gases (O₂) were sampled first and then carboys were filled to allow filtering for particulates. To obtain depth and higher frequency data, a RBR Concerto was attached to the bottle with sensors for pressure, temperature, fluorescence, and backscatter. A total of eight bottles were collected.

For dissolved oxygen, seawater was siphoned into 100 ml borosilicate glass bottles (nominal volume, actual volume was determined gravimetrically prior to the cruise), using silicone tubing and overflowing 2 times the bottle volume, and samples were immediately fixed. Oxygen in the samples was fixed with Manganese Sulphate and Alkaline Iodide solutions dispensed from calibrated pipettes. The fixing temperature was recorded on a hand-held thermometer. Immediately after fixing, the samples were stored until analysis.

Analytical methodology

Titrations for dissolved oxygen determination were made within the following 24 h using a Metrohm 916 Ti-Touch controller and 2 Metrohm Dosino 800 units for despensing Thiosulphate and Iodate solutions. A Metrohm Pt-Titrode electrode was used for detecting the potentiometric end-point of the titration. The titration sequence and data acquisition were controlled by Metrohm Tiamo software. The concentration of Thiosulphate was calibrated prior to starting oxygen analyses as well as blank determination. Dissolved oxygen concentration was calculated from the equations for solubility in seawater of Benson and Krause (1984). The analytical error was 0.084% (relative standard deviation).

References Cited

Benson B.B. and Krause D., 1984. The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere. Deep Sea Research Part B. Oceanographic Literature Review, 31 (12), 859.

Cruise report

Further information can be found in the DY112 Cruise report. Details of method protocols and instrumentation can be found in the DY111 Cruise report.

BODC Data Processing Procedures

The data received were loaded into the BODC database using established BODC data banking procedures. No unit conversion was necessary as the data were provided in equivalent units to the assigned BODC parameter code. A parameter mapping table is provided below:

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_GF2

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: DY112_BOTTLE_GF2

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.