Metadata Report for BODC Series Reference Number 2107880

• 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

Digitron TM-22 Digital Thermometer

The Digitron TM-22 is a water-resistant, hand-held digital thermometer. It complements Digitron's PM series of pressure instruments. Its typical battery life is 500 hours from two AA or equivalent cells. Temperature measurements are available in Celsius or Fahrenheit with a temperature range of -200 degC to +1350 degC/ -328 degF to +2462 degF.

For more information please see the document https://www.bodc.ac.uk/data/documents/nodb/pdf/digitron_tm22_datasheet.pdf.

Metrohm 794 Basic Titrino Titrator

The Metrohm 794 Basic Titrino is an all-purpose titrator used for dynamic and monotonic determination of solution concentrations. Titration modes of the instrument are constant or depending on the titration curve variable dosing of the titration reagent and Endpoint-Titration. The operation modes include; Dynamic Equivalence-point Titration (DET), Monotonic Equivalence-point Titration (MET), Set Endpoint Titration (SET), pH Calibration (CAL), Measuring (MEAS) and Titration Procedure (TIP) which links various commands and methods to a titration procedure. All operating modes of the Titrino can be combined to perform extensive analytical sequences.

Ready-to-start methods for the most common applications are stored in the internal method memory for example; the determination of the hardness of drinking water, diazotation of sulfonamides and primary amines, and determination of the peroxid number of edible oil sand fats. The operator is free to modify and overwrite the methods or to create and store new titration sequences.

The instrument consists of an exchange unit with a small display, which can be connected to either a magnetic stirrer (728), propeller rod stirrer (802) or Ti stand (703 or 727). Data exchange with a PC is possible with the Metrodata VESUV Software and with Metrodata TiNet Software complete keypad remote control, data acquisition and evaluation via PC is enabled.

Further details can be found in the manufacturer's user manual.

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.

RAPID cruise JC103 Discrete CTD salinity, oxygen and underway salinity samples

Originator's protocol for data acquisition and analysis

Sample collection and analysis

A total of 25 CTD casts were made during cruise JC103 and bottle samples were collected from 15 casts. The CTD and the 10 litre sampling bottles were washed with fresh water approximately every other cast. Water samples were taken from the bottles after three full rinses and were stored in a controlled temperature labroratory for 24 hours prior to analysis.

Samples were also taken from the non-toxic underway seawater supply located at approximately 5.5 metres deep with a flow through of approximately 24 litres per minute. Bottle samples were taken two to three times per day and the bottles were rinsed three times with freshwater then flushed three times with salt water before the sample was collected. Each full crate was deposited in the controlled temperature lab (18°C) and left for 24 hours before analysis.

The salinity samples were analysed using a Guildline Autosal 8400B which was installed in the temperature controlled lab and the bath temperature was set to 21°C. The salinometer was standardised using OSIL P156 standard seawater at the beginning of the cruise and then at the beginning and end of each crate of samples.

Oxygen samples were taken from the Niskin bottles using silicon tubing to transfer the water from the Niskin bottles to wide-neck borosilicate glass sampling bottles. 1ml of manganous chloride and 1ml of alkaline iodide solution were injected into the sample bottles. The stopper was then inserted and the sample was shaken for 30 seconds, this was repeated after 30 minutes. The temperature was recorded at the time of oxygen fixation and the samples were then anaylsed 12-24 hours later using a Metrohm Titrino titrator with amperometric end point detection.

Data processing

The salinometer data were formatted into spreadsheets and a salinometer drift was applied.

The oxygen data were stored in a Microsoft Excel spreadsheet. Data quality flags were applied and the data file was converted to netCDF format along with the salinometer data for MATLAB processing.

References

Smeed, D.A. et al. (2015) RRS James Cook Cruise JC103, 23 Apr - 03 Jun 2014. RAPID moorings cruise report. Southampton, GB, National Oceanography Centre, 211pp. (National Oceanography Centre Cruise Report, 30).

BODC data processing procedures

The data were submitted to BODC in netCDF format which was converted to ASCII before BODC parameter codes were assigned. The data were then reformatted and loaded to BODC's Oracle database. The originator's variables and the parameters they were mapped to are shown below:

Data quality report

None (BODC assessment)

Problem report

None (BODC assessment)

Project Information

RAPID- Will the Atlantic Thermohaline Circulation Halt? (RAPID-WATCH)

RAPID-WATCH (2007-2014) is a continuation programme of the Natural Environment Research Council's (NERC) Rapid Climate Change (RAPID) programme. It aims to deliver a robust and scientifically credible assessment of the risk to the climate of UK and Europe arising from a rapid change in the Atlantic Meridional Overturning Circulation (MOC). The programme will also assess the need for a long-term observing system that could detect major MOC changes, narrow uncertainty in projections of future change, and possibly be the start of an 'early warning' prediction system.

The effort to design a system to continuously monitor the strength and structure of the North Atlantic MOC is being matched by comparative funding from the US National Science Foundation (NSF) for the existing collaborations started during RAPID for the observational arrays.

Scientific Objectives

• To deliver a decade-long time series (2004-2014) of calibrated and quality-controlled measurements of the Atlantic MOC from the RAPID-WATCH arrays.
• To exploit the data from the RAPID-WATCH arrays and elsewhere to determine and interpret recent changes in the Atlantic MOC, assess the risk of rapid climate change, and investigate the potential for predictions of the MOC and its impacts on climate.

This work will be carried out in collaboration with the Hadley Centre in the UK and through international partnerships.

Mooring Arrays

The RAPID-WATCH arrays are the existing 26°N MOC observing system array (RAPIDMOC) and the WAVE array that monitors the Deep Western Boundary Current. The data from these arrays will work towards meeting the first scientific objective.

The RAPIDMOC array consists of moorings focused in three geographical regions (sub-arrays) along 26.5° N: Eastern Boundary, Mid-Atlantic Ridge and Western Boundary. The Western Boundary sub-array has moorings managed by both the UK and US scientists. The other sub-arrays are solely led by the UK scientists. The lead PI is Dr Stuart Cunningham of the National Oceanography Centre, Southampton, UK.

The WAVE array consists of one line of moorings off Halifax, Nova Scotia. The line will be serviced in partnership with the Bedford Institute of Oceanography (BIO), Halifax, Canada. The lead PI is Dr Chris Hughes of the Proudman Oceanographic Laboratory, Liverpool, UK.

All arrays will be serviced (recovered and redeployed) either on an annual or biennial basis using Research Vessels from the UK, US and Canada.

Modelling Projects

The second scientific objective will be addressed through numerical modelling studies designed to answer four questions:

• How can we exploit data from the RAPID-WATCH arrays to obtain estimates of the MOC and related variables?
• What do the observations from the RAPID-WATCH arrays and other sources tell us about the nature and causes of recent changes in the Atlantic Ocean?
• What are the implications of RAPID-WATCH array data and other recent observations for estimates of the risk due to rapid change in the MOC?
• Could we use RAPID-WATCH and other observations to help predict future changes in the MOC and climate?

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JC103_CTD_C001

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.

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: