Metadata Report for BODC Series Reference Number 2138669

• 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

SEAL Analytical QuAAtro colorimetric autoanalyser

The SEAL QuAAtro high Performance Microflow Analyzer is the latest generation of the original world-class Technicon^TM Segmented Flow Analysis (SFA) systems.

A basic SFA system consists of an autosampler, a peristaltic pump, a chemistry manifold, a detector and data acquisition software. Sample and reagents are pumped continuously through the chemistry manifold. Air bubbles are introduced at regular intervals forming unique reaction segments which are mixed using glass coils. Glass is ideal, as it is inert, stays clean and enables easy visual checks.

In SFA, reactions run to completion and the ratio of sample to reagents in the detector reaches a constant maximum value. This results in ultra-low detection limits and exceptional reproducibility. Variations in reaction time, temperature and sample matrix do not affect the results as they do in other colorimetric techniques, such as flow injection analysis, where the reaction is not brought to completion.

QuAAtro is a microflow SFA system, the internal diameter of all glassware being 1 mm. This reduces reagent consumption and increases throughput, with most methods running at 100 - 120 samples hour. The integrated enclosed manifold and detector are heated to 37 °C. Flow stability is ensured as the optimal bubble frequency for each method is programmed by silent air valves. Automatic start-up, method changeover and shutdown allows true unattended operation and overnight running. QuAAtro checks its own performance, with automatic monitoring of noise, drift, bubble pattern and light energy, before and during a run.

Up to four methods can run at the same time on one console, and there is a special 5-channel version for nutrients in seawater. Two consoles can be combined to give an 8-channel system.

Further details can be found in the manufacturer's specification sheet.

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.

JC090 inorganic nutrients sampling document

Originator's protocol for data acquisition

The following contains extracts from the JC090 cruise report.

The RRS James Cook 090 cruise was the concluding phase of the fieldwork for the Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study (OSMOSIS) consortium and sought to recover 9 moorings and 2 gliders to conduct hydrographic and biogeochemical measurements for mooring and glider calibration, and to obtain opportunistic measurements of upper-ocean microstructure and air-sea CO₂ fluxes. The cruise departed on the 30 August 2013 from the port of Vigo, Spain and returned on the 17 September 2013 at the port of Santander, Spain.

Sample collection

A CTD rosette was used for collecting water samples from various depths between the surface and 200 m. The rosette had 24 Niskin bottles with a 20 litre capacity. Samples were also collected from the ships underway system (~ 5 m depth) approximately every 6 hours starting at 11:00 hours (GMT) on 02 Sep 2013 and finishing at 17:00 hours (GMT) on 13 Sep 2013.

A 10 ml water sample collected for nutrient analysis was placed in a 15 ml labeled centrifuge tube. The sample was then frozen for later analysis at the National Oceanography Centre, Southampton.

Sample analysis

The nutrients were analysed at NOCS using the SEAL Analytical UK Ltd segmented-flow autoanalyser (QuAAtro), for nitrate, nitrite, phosphate and silicate, using the methodology of Kirkwood (1996). The following calibrations were applied:

• Nitrate and Nitrite linear fit, r² = 1.000 (calibration concentrations - 3.034, 6.067, 9.101,12.134 µmol l^-1)
• Silicate linear fit, r² = 0.9999 (calibration concentrations - 2.482, 4.964, 7.445, 9.927 µmol l^-1)
• Nitrite linear fit, r² = 0.9999 (calibration concentrations - 0.507, 1.014, 1.521, 2.027 µmol l^-1)
• Phosphate linear fit, r² = 0.9999 (calibration concentrations - 0.502, 1.005, 1.507, 2.010 µmol l^-1)

BODC data processing procedures

Inorganic nutrients data were supplied to BODC in Microsoft Excel format and values were extracted for loading into BODC's ocean database under the ORACLE Relational Database Management System. Data that were considered unrealistic were flagged suspect.

Content of data series

Data quality report

Negative nitrite values are below the detection limit of the analyser for the CTD and underway samples. Negative silicate values were also present due to the same reason for the CTD samples. These values have been assigned an 'M' flag by BODC.

References

Kirkwood, D. S. (1996.) Nutrients: Practical notes on their determination in seawater. In: ICES Techniques in Marine Environmental Sciences Report 17, International Council for the Exploration of the Seas, Copenhagen (1996), p.25

Naveira-Garabato A. et al. (2013). 'Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study (OSMOSIS)'. Cruise Report No. 25 National Oceanography Centre, Southampton.

Project Information

Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study (OSMOSIS)

Background

The Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study (OSMOSIS) consortium was funded to deliver NERC's Ocean Surface Boundary Layer (OSBL) programme. Commencing in 2011, this multiple year study will combine traditional observational techniques, such as moorings and CTDs, with the latest autonomous sampling technologies (including ocean gliders), capable of delivering near real-time scientific measurements through the water column.

The OSMOSIS consortium aims to improve understanding of the OSBL, the interface between the atmosphere and the deeper ocean. This layer of the water column is thought to play a pivotal role in global climate and the productivity of our oceans.

OSMOSIS involves collaborations between scientists at various universities (Reading, Oxford, Bangor, Southampton and East Anglia) together with researchers at the National Oceanography Centre (NOC), Scottish Association for Marine Science (SAMS) and Plymouth Marine Laboratory (PML). In addition, there are a number of project partners linked to the consortium.

Scientific Objectives

• The primary goal of the fieldwork component of OSMOSIS is to obtain a year-long time series of the properties of the OSBL and its controlling 3D physical processes. This is achieved with an array of moorings (two nested clusters of 4 moorings, each centred around a central mooring) and gliders deployed near the Porcupine Abyssal Plain (PAP) observatory. Data obtained from this campaign will help with the understanding of these processes and subsequent development of associated parameterisations.
• OSMOSIS will attempt to create parameterisations for the processes which determine the evolving stratification and potential vorticity budgets of the OSBL.
• The overall legacy of OSMOSIS will be to develop new (physically based and observationally supported) parameterisations of processes that deepen and shoal the OSBL, and to implement and evaluate these parameterisations in a state-of-the-art global coupled climate model, facilitating improved weather and climate predictions.

Fieldwork

Three cruises are directly associated with the OSMOSIS consortium. Preliminary exploratory work in the Clyde Sea (September 2011) to hone techniques and strategies, followed by a mooring deployment and recovery cruise in the vicinity of the Porcupine Abyssal Plain (PAP) observatory (in late Summer 2012 and 2013 respectively). Additional opportunist ship time being factored in to support the ambitious glider operations associated with OSMOSIS.

Instrumentation

Types of instrumentation and measurements associated with the OSMOSIS observational campaign:

• Ocean gliders
• Wave rider buoys
• Towed SeaSoar surveys
• Microshear measurements
• Moored current meters, conductivity-temperature sensors and ADCPs
• Traditional shipboard measurements (including CTD, underway, discrete nutrients, LADCP, ADCP).

Contacts

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JC090_CTD_JC090_006

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: JC090_CTD_JC090_006

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.