Metadata Report for BODC Series Reference Number 1979698

• 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

VG PRISM III Isotope Ratio Mass Spectrometer

A modular benchtop isotope ratio mass spectrometer which can operate in dual inlet or continuous flow modes. It is designed to measure stable isotope ratios of N2, CO2, H2, SO2, SF6 and O2 and C. It has a Multi-collector with four Faraday buckets, featuring integral suppressers. The central bucket is fixed, and the others are externally moveable using precision adjusters. The ion optics have a horizontal geometry, and the design allows individual access to the source and collectors through the lids of the housings. A manifold option, HD option and Differential Pumping option are available depending on user requirements. Its precision is better than 0.05 permille. Sample size can range from 100 ul to 150 ul.

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

VG SIRA 10 Isotope-Ratio Mass Spectrometer

A laboratory Isotope-Ratio Mass Spectrometer (IRMS) which operates in dual inlet flow mode for the measurement of the isotope ratios ¹³C/¹²C,¹⁸O/¹⁶O and ³⁴S/³²S contained in many compounds. It can determine the ¹³C/¹²C of carbon in different materials (organic matter, dissolved carbon in water) with an accuracy of ± 0.1 ‰, determine ¹³C/¹²C and ¹⁸O/¹⁶O in carbonates with an accuracy of 0.1 ‰ and 0.2 ‰ respectively, and can also determine ¹⁸O/¹⁶O and ³⁴S/³²S in sulphates and ³⁴S/³²S in sulphides with an accuracy of ± 0.1 ‰.

The instrument is a gas analyser, therefore the natural sample must be processed first (e.g. combustion, acid attack, or purification), in order to obtain a directly analysable gas. The prepared gases, CO₂ or SO₂ are then ionised and analysed for their isotopic content by the IRMS. This model is no longer in production.

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.

JR15003 CTD Bottle Oxygen Isotope Samples for CGS Project

Originator's Protocol for Data Acquisition and Analysis

Samples for determination of the ratio of stable oxygen isotopes of seawater (δ¹⁸O) were taken from three Collaborative Gearing Scheme (CGS) stations during cruise JR15003, between 25^th and 28^th December 2015. Bottle samples were taken using Niskin bottles on a 24 way rosette sampler attached to an SBE 911plus CTD unit. Samples were taken from the Niskin bottles into 50 ml glass bottles, which were crimp-sealed immediately and stored in the dark at 4°C during transport to the UK. Samples were analysed at the British Geological Survey, Keyworth. Samples were run on a VG Isoprep 18 and SIRA 10 mass spectrometer, with duplicate analyses indicating a precision better than +/-0.02‰, and δ¹⁸O data being standardised relative to Vienna Standard Mean Ocean Water.

For more information please see the cruise report.

BODC Data Processing Procedures

The oxygen isotopes data were supplied to BODC in .xlsx format. Data were then loaded into BODC's database using established BODC data banking procedures.

The originator's variables were mapped to appropriate BODC parameter codes as follows:

JR15003 CTD Bottle Particulate Organic Carbon, Particulate Nitrogen, delta¹³C, and delta¹⁵N Samples for CGS Project

Originator's Protocol for Data Acquisition and Analysis

Particulate organic carbon (POC) and particulate nitrogen (PN) samples were taken from three Collaborative Gearing Scheme (CGS) stations during cruise JR15003, between 25^th and 28^th December 2015. Bottle samples were taken using Niskin bottles on a 24 way rosette sampler attached to an SBE 911plus CTD unit. POC and PN samples were obtained by filtration using GF/F filters and a custom-built overpressure system. Samples were then snap-frozen at -80 °C and stored at -20 °C. All samples were shipped back to the UK for analysis. Samples for POC and PN analysis were decarbonated prior to analysis by rewetting with milli-Q water and fuming with 50% HCl for 24 hours and then dried at 50 °C overnight. Samples were analysed for the concentration and isotopic composition of POC and PN using a Carlo Erba NA 2500 elemental analyser in-line with a VG Prism III IRMS. Isotopic data were referenced to Vienna Pee Dee Belemnite (per mille VPDB) for delta¹³C_POC, and atmospheric N₂ (per mille AIR) for delta¹⁵N_PN, using PACS isotopic reference material. POC and PN concentrations were calibrated to an acetanilide elemental standard. Analytical precision was around 0.2 per mille. The raw POC and PN data expressed in µg L^-1 are also available upon request.

For more information please see the cruise report.

BODC Data Processing Procedures

The POC, PN and isotopic data were supplied to BODC in .xlsx format. Data were then loaded into BODC's database using established BODC data banking procedures.

The originator's variables were mapped to appropriate BODC parameter codes as follows:

Project Information

NE/K010034/1 Isotopic characterisation of nutrient dynamics and Upper Circumpolar Deep Water behaviour in the West Antarctic Peninsula sea ice environment

Introduction

Solo NERC funded grant, 'isotopic characterisation of nutrient dynamics and Upper Circumpolar Deep Water (UCDW) behaviour in the West Antarctic Peninsula sea ice environment' with grant reference NE/K010034/1. The project is led by Dr Sian Henley (University of Edinburgh, School of Geosciences).

Background and Objectives

The research project aims to examine ways in which ongoing climate change and sea ice decline at the West Antarctic Peninsula (WAP) are influencing nutrient budgets and biogeochemical cycling throughout the region. The WAP is an ecologically important region of high primary productivity, where nutrient cycling is known to be crucial to phytoplankton production and its relationship with carbon dioxide dynamics. The study comprises of three components:

• A time-series study over three austral summer growing seasons in Ryder Bay, WAP, to examine temporal changes in fixed nitrogen budgets and cycling, in relation to inter-annual variability in sea ice, water column structure and productivity.
• A ship-based transect from the shelf break to Marguerite Bay to examine deep-water behaviour and its impact on the supply of nutrients to high productivity coastal regions.
• Ship-based sampling across the wider WAP shelf region to examine spatial variability in nutrient dynamics, productivity, sea ice and physical oceanography, and give a broader context to the time-series study.

Fieldwork

Ship based sampling was completed on-board RRS James Clark Ross cruise JR20141231 (JR307, JR308) comprising of full depth CTDs, water sampling for analysis on-board for macro nutrient concentration and RNA sequencing of organic matter. Times Series, study data were collected as part of the Rothera Time Series (RaTS), a long-term monitoring project conducted by the British Antarctic Survey since 1997.

Data Availability

The NERC funded data collected under NE/K010034/1 is restricted to the Principal Investigator for 2 years from the point of data collection. Data is freely available to the public beyond this date.

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JR15003_CTD_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

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:

Appendix 1: JR15003_CTD_CTD02

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

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