Metadata Report for BODC Series Reference Number 2280930

• 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

Skalar San+ Autoanalyzer

The San+ Autoanalyzer is an Automated Wet Chemistry Analyzer (Continuous Flow Analyzer) which has been designed as a modular system to measure a variety of water chemistry characteristics, such as nutrient concentrations in seawater. Individual modules are tailored to specific needs. It uses Continuous Flow Analysis (CFA), allowing up to 16 analytical measurements to be made on a single sample simultaneously. The system comprises a sampler, chemistry section, detector and specialist software.

Chemistry section
The San+ includes a chemistry section which has hundreds of applications. It houses up to five chemistry cartridges with built-in dosing pump and air injection systems, up to five interchangeable cartridges with build-in photometric detectors and five separate waste receptacles. The throughput of the analyser depends upon application and can vary from 25 to 120 analyses per hour. It has a double diameter pump deck for accurate dosing with 32 pump tubes, two separated pump decks for 2 x 2 channel concept, and controlled synchronised eight channel air injection with separate built-in compressor for increased flow stability and fast start-up. It has easy access to chemistry cartridges with flexible ultra low carry-over connections between dialysers, reactors, coils, flow cells and other components, leak detection, 3-cuffs long life pump tubes, and has manually operated and automatic rinsing valves for easy automatic start up and overnight operation.

Detectors
The San+ range of detectors comprises dual channel colorimetric detectors, the unique matrix correction detector with automatic background correction for difficult sample matrixes, but also covers a range of detectors for I.R., U.V., fluorimetry, ISE, flame photometry, refractometers, density meters, etc.

Software
The San+ 'Flow Access' windows software package controls the complete analyser, with auto start-up, function control, and auto-scaling, pre-and post run sample dilutions, result calculation and statistics. Up to 16 channels can be handled simultaneously, with multiple samplers, and chemistries can be grouped for analysis.

The San+ is also known as San++.

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.

UKOA JR271/JR20120601 micro-molar nutrient measurements from CTD bottle, GoFlo, underway and bioassay samples

Originator's Protocol for Data Acquisition and Analysis

Discrete CTD samples for the analysis of inorganic nutrients (nitrate and nitrite, phosphate and silicate) were collected from the 20 L Niskin bottles on the CTD rosette using a silicon tube into 30 ml coulter counter vials, after samples for oxygen, dissolved inorganic carbon and alkalinity were drawn. Samples were collected from all the stations at all depths on the cruise. In addition, every two hours during the cruise, additional surface samples from the non-toxic underway supply were collected in vials and analysed. Sampling vials were rinsed at least 3 times before sample collection, by half filling with the seawater being sampled and shaking vigorously. Samples from incubation experiments were also analysed for inorganic nutrients during the cruise.

Nutrient free vinyl gloves were worn during sampling to avoid potential contamination. Samples were analysed immediately after collection to avoid any possibility of biological growth or decay in the samples. On a few occasions, samples were stored in the fridge and analysed within a maximum of 12 hours. Inorganic nutrients were measured using the Skalar San+ segmented flow autoanalyser. The system was set up for analysis and data logging with the Flow Access software package version 1.2.5. The general analytical method was based on colorimetric chemical reactions of nutrient with specific metals and the intensity of the colour of the solution was proportional to the concentration of the reacted nutrient.

The nutrient concentrations were determined by measuring the absorbance of light using a photometer. The instrument was calibrated with a set of 4 working standards with nitrate, silicate and phosphate concentrations appropriate to the samples being analysed.

Stock solutions (5 mM) were used to prepare new working standards every three to four days. Stock standards were prepared with Milli-Q water, while working standards were prepared in a saline matrix of 40 g NaCl per 1 L of Milli-Q water (artificial seawater).

Most CTD casts were analysed in single runs together with underway and/or samples from bioassays. Every run included a set of standards, wash and drift cups and certified low nutrient sea water in order to test for contamination of the matrix and samples, and OSIL certified standards to monitor the performance of the analyser. A new cadmium column was placed at the beginning of the cruise and the autoanalyser pump tubing was changed every 7 to 10 days.

The consistency of the analysis was monitored by recording the baseline in digital units, and calibration coefficients of the three nutrient channels measured over time. The variations observed throughout the cruise were within the analytical error of the method. The consistency of the analyses was also tested by measuring on every run OSIL certified standards. A total of 74 aliquots of these standards were measured and the mean values were 9.97±0.16, 1.00±0.02 and 9.98±0.05±M for nitrate, phosphate and silicate respectively. The standard deviation of the mean nutrient concentrations of these standards represented variations of less than 2.0±.

In order to check the performance and reproducibility of the results, one of the samples was measured in triplicate in each run and the values averaged to give a mean value and a standard deviation error. The average standard deviations for all the runs were 0.04, 0.01 and 0.007±M for NO₃ ^2-,PO₄ ^3- and Si(OH)₄respectively. The precision of the method was further tested analysing the variations of the complete set of the measured standards.

References Cited

Kirkwood D.S., 1989. Nutrients: Practical notes on their determination in sea water. ICES Techniques in Marine Environmental Sciences, No 17.

Instrumentation Description

Skalar San+ segmented flow autoanalyser

BODC Data Processing Procedures

Data were submitted to BODC in Microsoft Excel spreadsheet format and saved to the BODC archive with reference USO140139. Sample metadata provided (Station, Cast number, position date/time, niskin bottle number and sample depth) were checked against information held in the database. Underway sample U07 was loaded with date 04 June 2012 rather than 03 June 2012 that was provided. CTD metadata were matched to existing entries in the database using Niskin bottle number and depth. For casts 6, 7, 11, 18, 28, 66 and 69 the originator had provided firing sequence rather than rosette position. There were no major discrepancies between the depths provided and those assigned in the database.

No unit conversions were necessary as the units provided matched the units for the parameter codes in the BODC Parameter Dictionary. The dataset was loaded to the database following BODC protocols.

A parameter mapping table is provided below;

Data Quality Report

The data provided to BODC were quality controlled and flagged as improbable where nutrient concentrations were negative.

Problem Report

Not applicable for this dataset.

Project Information

UKOARP Theme B: Ocean acidification impacts on sea surface biology, biogeochemistry and climate

The overall aim of this theme is to obtain a quantitative understanding of the impact of ocean acidification (OA) on the surface ocean biology and ecosystem and on the role of the surface ocean within the overall Earth System.

The aims of the theme are:

• To ascertain the impact of OA on planktonic organisms (in terms of physiological impacts, morphology, population abundances and community composition).
• To quantify the impacts of OA on biogeochemical processes affecting the ocean carbon cycle (both directly and indirectly, such as via availability of bio-limiting nutrients).
• To quantify the impacts of OA on the air-sea flux of climate active gases (DMS and N₂O in particular).

The main consortium activities will consist of in-situ measurements on three dedicated cruises, as well as on-deck bioassay experiments probing the response of the in-situ community to elevated CO₂. Most of the planned work will be carried out on the three cruises to locations with strong gradients in seawater carbon chemistry and pH; the Arctic Ocean, around the British Isles and the Southern Ocean.

Weblink: http://www.oceanacidification.org.uk/research_programme/surface_ocean.aspx

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JR20120601_CTD_CTD017s

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: JR20120601_CTD_CTD017s

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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