Metadata Report for BODC Series Reference Number 2206877

• 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

SPX Bran+Luebbe Autoanalyser 3

The instrument uses continuous flow analysis (CFA) with a continuous stream of material divided by air bubbles into discrete segments in which chemical reactions occur. The continuous stream of liquid samples and reagents are combined and transported in tubing and mixing coils. The tubing passes the samples from one apparatus to the other with each apparatus performing different functions, such as distillation, dialysis, extraction, ion exchange, heating, incubation, and subsequent recording of a signal.

An essential principle of the system is the introduction of air bubbles. The air bubbles segment each sample into discrete packets and act as a barrier between packets to prevent cross contamination as they travel down the length of the tubing. The air bubbles also assist mixing by creating turbulent flow (bolus flow), and provide operators with a quick and easy check of the flow characteristics of the liquid.

Samples and standards are treated in an exactly identical manner as they travel the length of the tubing, eliminating the necessity of a steady state signal, however, since the presence of bubbles create an almost square wave profile, bringing the system to steady state does not significantly decrease throughput and is desirable in that steady state signals (chemical equilibrium) are more accurate and reproducible.

The autoanalyzer can consist of different modules including a sampler, pump, mixing coils, optional sample treatments (dialysis, distillation, heating, etc), a detector, and data generator. Most continuous flow analyzers depend on color reactions using a flow through colorimeter, however other methods have been developed that use ISE, flame photometry, ICAP, fluorometry, and so forth.

More details can be found in the manufacturer's introduction to autoanalysers andinstrument description.

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.

Inorganic nutrients (Nitrate, Silicate, and Phosphate) for Cruise JC150

Originator's Protocol for Data Acquisition and Analysis

Acquisition description:

Sampling methodology

CTD and FISH samples along the ~ 1800 nm transect. Specifically, micromolar concentrations of phosphate, nitrate, nitrite and silicate were made as well as nanomolar concentrations of nitrate, phosphate and nitrite.

Acid clean 60m ml HDPE Nalgene bottles were used for all the nutrient sampling, these were aged,acid washed and cleaned initially, and stored with a 10% acid solution between sampling. Water column depth profile samples were taken from the OTE bottles from the Trace Metal CTD system and sub-sampled into the Nalgene nutrient bottles from within the trace metal clean laboratory onboard the RRS James Cook. The sample bottle was washed 3 times before taking final sample, and capping tightly. These were then taken immediately to the nutrient analysers in the chemistry lab and analysis conducted as soon as possible after sampling. Nutrient free (Semperguard) gloves were used and other clean handling protocols were adopted as close to those according to the GO-SHIP protocols.

Analytical methodology

The micro-molar segmented flow colorimetric auto-analyser used was the PML 5- channel (nitrate, nitrite, phosphate, silicate and ammonium) Bran and Luebbe AAIII system, using classically proven analytical techniques. The instrument was calibrated with home produced nutrient stock standards and then compared regularly against Nutrient Reference Materials, from KANSO Technos, Japan for quality control and checking of analytical standardisation. Specifically batches CA and BU were used during the cruise. The analytical chemical methodologies used were according to Brewer and Riley (1965) for nitrate and Kirkwood (1989) for silicate and phosphate. Nanomolar nitrate and phosphate were analysed using segmented flow colorimetric techniques with 2 metre Liquid waveguides as the analytical flow cells to improve the analytical detection limits. Nitrate used the same colorimetric methods as for the micromolar system and phosphate used the Zhang and Chi (2002) method.

References Cited

Brewer P.G. and Riley J.P., 1965. The automatic determination of nitrate in seawater. Deep SeaResearch, 12, 765-72.

Kirkwood D., 1989. Simultaneous determination of selected nutrients in seawater. ICES CM1989/C:29.

Jia-Zhong Z. and Jie C., 2002. Automated Analysis of Nanomolar Concentrations of Phosphatein Natural Waters with Liquid Waveguide. Environ. Sci. Technol., 36 (5), pp 1048-1053

BODC Data Processing Procedures

Data received were loaded into the BODC database using established BODC data banking procedures. A parameter mapping table is provided below:

Nutrient (Ammonium, Nitrite) CTD water samples for Cruise JC150

Originator's Protocol for Data Acquisition and Analysis

Methods

Sampling:

Acid clean 60 ml HDPE Nalgene bottles were used for all the nutrient sampling, these were initially aged, acid washed and cleaned, and then stored with a 10 % acid solution between samplings. Water column depth profile samples were taken from the OTE bottles from the Trace Metal CTD system and sub-sampled into the Nalgene nutrient bottles from within the trace metal clean laboratory onboard the RRS James Cook. The sample bottles were washed 3 times before taking the final sample, and being capped tightly. These were then taken immediately to the nutrient analysers in the chemistry lab and analysis was conducted as soon as possible after sampling. Nutrient free (Semperguard) gloves were used and other clean handling protocols were adopted as close as possible to the GO-SHIP protocols.

Analysis:

The micro-molar segmented flow colorimetric auto-analyser used was the PML 5- channel (nitrate, nitrite, phosphate, silicate, and ammonium) Bran and Luebbe AAIII system, using classically proven analytical techniques. The instrument was calibrated with home produced nutrient stock standards and then compared regularly against Nutrient Reference Materials, from KANSO Technos, Japan for quality control and checking of analytical standardisation. The analytical chemical methodologies used were according to Grasshoff (1976) for nitrite, and Mantoura and Woodward (1983) for dissolved ammonium. Where required, nanomolar analyses were carried out: for ammonium using a fluorimetric detection differential gas diffusion technique, based on Jones R.D, 1991; for nitrite using segmented flow colorimetric techniques, same as for the micromolar system, with 2 metre Liquid waveguides as the analytical flow cells to improve the analytical detection limits.

References Cited

Jones R.D., 1991. An improved fluorescence method for the determination of nanomolar concentrations of ammonium in natural waters. Limnology and Oceanography, 36, 814-819.

Mantoura, R.F.C and Woodward, E.M.S, 1983. Estuarine, Coastal and Shelf Science, 17, 219-224.

JC150 Cruise report

Further information can be found on page 37 of the JC150 Cruise report.

BODC Data Processing Procedures

Data were submitted containing dissolved nutrient sample measurements of ammonium, and nitrite data. 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

BODC performed quality control checks on the data. Any data values deemed suspicious by the Originator were applied an 'L' flag. Any data values which were below the detection limit of the instrument were substituted with the Limit of Detection (L.O.D.) value (0.01 for Nitrite, 0.03 for Ammonium) and applied a '<' flag.

Project Information

Zinc, iron and phosphorous co-limitation in the Ocean: ZIPLOc

ZIPLOc is an 3 year project that aims to measure how zinc and phosphorous control biological activity in the North Atlantic subtropical gyre using novel measurement techniques. The observations made will be further explored using the latest modelling techniques over decadal timescales and in other basins.

The research aims to make an improvement in our overall understanding of how subtropical gyre ecosystems respond to ongoing climate change.

The project is led by the University of Liverpool, Earth, Ocean and Ecological Sciences and is a collaboration with the University of Southampton, School of Ocean and Earth Science. The project received funding from the Natural Environmental Research Council and runs between January 2017 and February 2020.

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JC150_UCCTD_CTD037T

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: JC150_UCCTD_CTD037T

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.