Metadata Report for BODC Series Reference Number 1979625

• 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

Technicon AutoAnalyzer II (AAII)

The AAII is a segmented flow analyzer used for automated colorimetric analysis. The apparatus uses 2 mm diameter glass tubing and pumps reagents at flow rates of 2 to 3 ml s^-1, producing results at a typical rate of 30 to 60 samples per hour. The system comprises an autosampler, peristaltic pump, chemistry manifold a detector and a data acquisition software.

This instrument was replaced by the AA3 in 1997 which was upgraded to the AA3 HR systems in 2006.

Specifications

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 Dissolved Inorganic Nutrient Samples for CGS Project

Originator's Protocol for Data Acquisition and Analysis

Dissolved Inorganic Nutrient 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. Nutrient samples were filtered through 0.2 µm supor membrane filters. Nutrient samples were snap-frozen at -80°C and then stored at -20°C. Silicic acid samples were stored in the dark at 4°C. Prior to nutrient analysis, samples were thawed for 48 hours to ensure complete redissolution of secondary silicate precipitates to silicic acid. Concentrations of nitrate+nitrite, nitrite, ammonium, phosphate and silicic acid were analysed using a Technicon AAII segmented flow autoanalysis system with reference materials from KANSO Ltd (Japan) at Plymouth marine Laboratory, UK. Raw data were corrected to elemental standards and ambient ocean salinity and pH. Samples were assayed in duplicate and standard deviation was generally better than 0.2 µmol L^-1 for nitrate+nitrite, 0.01 µmol L^-1 for nitrite, 0.02 µmol L^-1 for phosphate, and 0.6 µmol L^-1 for silicic acid.

For more information please see the cruise report.

BODC Data Processing Procedures

The nutrient 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_CTD01

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_CTD01

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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