Metadata Report for BODC Series Reference Number 2138565

• 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

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 Discrete CTD Oxygen Sampling Document

The following contains extracts from the JC090 cruise report.

Originator's Protocol for Data Acquisition and Analysis

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 31 August 2013 from the port of Vigo, Spain and returned on the 16 September 2013 at the port of Santander, Spain.

Sample collection

Water samples were collected for determination of dissolved oxygen concentrations. Samples were taken from two 1000 m CTD casts which calibrated the Aanderaa oxygen optode sensors on seagliders SG533 and SG566 and from a 200 m CTD cast which calibrated the WetLabs sensor, close to the gliders' positions at the South West outer mooring. Samples also provided a calibration of the CTD oxygen sensor.

Calibrated volumes of 125 ml borosilicate glass Iodine flasks were rinsed with water drawn from the same Niskin bottle for 30-40 seconds. The flask was then filled completely, checking for the absence of air bubbles. The temperature of the water samples were recorded at the time of sampling using a handheld digital temperature probe. To fix the oxygen, 1 cm³ of 3 mol dm^-3 Manganese Chloride Tetrahydrate (MnCl₂) and 1.00 cm³ 4.0 mol dm^-3 Sodium Iodide/8.0 mol dm^-3 Sodium Hydroxide (NaOH/NaI) were added. Samples were then sealed and shaken to mix the reagents. The shaking was repeated after 20-30 minutes and then left overnight.

Sample analysis

Sampling analysis was performed in a temperature controlled lab (20° C) on the RRS James Cook. Each sample had 1 cm³ of 5 mol dm^-3 Sulphuric acid added to the sample along with a magnetic stir bar. Titration was performed with 0.2 mol dm^-3 Sodium Thiosulphate Pentahydrate till end point. Prior to the analysis of each batch of samples, two test samples containing fixed tap water were titrated, and a further test sample was titrated after each pause in the sequence of analysis. The temperature was recorded at the time of titration using a handheld digital temperature probe.

BODC Data Processing Procedures

Discrete oxygen samples were provided to BODC in Mstar format. The Mstar software is written in Matlab and stores the data in NetCDF. Oxygen values, together with associated rosette positions and WOCE bottle flags, were extracted from the Mstar files and saved in .csv format.

Bottle firing pressures were extracted from Sea-Bird .btl files (also provided by the Data Originator) and merged with the sample data. Depths were derived from the pressures by BODC.

The data were loaded to BODC's ORACLE Relational Database. Data that were considered unrealistic were flagged suspect.

Content of data series

References

Naveira-Garabato, A. C. 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_001

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_001

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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