Metadata Report for BODC Series Reference Number 2101675

• 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

Lachat QuikChem 8500 flow injection analyzer (FIA) and Ion Chromatography (IC) system

The Lachat QuikChem 8500 can operate FIA and IC simultaneously and independently on the same instrument platform. FIA and IC are complementary analytical techniques that are commonly used in the same laboratory.

Instrument includes - sampler, dilutor, sampling pump, electronics unit, and data station.

Flow injection analysis is ideally suited for processing relatively large numbers of samples. Ion Chromatography adds the power to profile samples for a class of ionic species.

FIA Productivity Characteristics

• Fast Startup - ~5 minutes
• Rapid Analysis - 20 to 60 seconds is typical
• High Sample Throughput - 60 to 120 samples per hour is typical
• Broad Working Range - Parts per trillion to percents
• Complete Baseline Resolution - No carryover between samples
• Wide Dynamic Range - 2 to 3 decades is typical
• Fast Shutdown - ~5 minutes
• Rapid Method Changeover - ~10 minutes

New FIA Features

• Run up to 5 channels for high productivity analysis or dedicated operation.
• New 2-cm flow cell methods allow more signal for detection at lower levels.
• Run Omnion 3.0 software on Windows XP, Vista, or Windows 7 operating systems.
• Interface Omnion software in multiple languages - including Spanish, German, French, Portuguese, and Italian.

For more information about this model see the manufactures data sheet - Lachat QuikChem 8500.

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.

JC086 discrete dissolved inorganic nutrients sampling document

Originator's protocol for data acquisition and analysis

The following information contains extracts from the JC086 cruise report.

Water samples were drawn from the CTD rosette bottles deployed during the cruise for ammonia, phosphate, silicate, nitrate and nitrite, with the majority of the sampling effort concentrated in areas of the water column corresponding with changes in water mass. Samples were also drawn from the ships non-toxic water supply.

SAMS Analysis

Samples were collected in 125 ml acid cleaned polythene bottles directly from CTD spigots without the use of a tube. Samples were stored in a fridge prior to analysis. The analysis was carried out within 24 hours of sample collection with a Lachat Quick Chem 8500 flow injection autoanalyser using the manufacturer's recommended methods.

Samples were measured in triplicate to identify instrument precision. A stock mixed standard was prepared in deionized water with subsequent dilutions made in OSIL Low Nutrient Sea Water using the instrument auto-dilutor facility. Five standard concentrations and a blank were run in all cases and new standards were prepared every 48 hours. Using standards prepared in Low Nutrient Sea Water removes the need to do a separate salt correction. Three standard concentration ranges were prepared for the non-toxic and CTD samples depending on expected nutrient concentration.

NOC Analysis

Samples were taken in 30ml plastic vials which were filled up to 2/3 of the total volume to allow expansion of water. Samples were labelled and stored in the freezer until analysis. The analysis was carried out at NOCS using a Quattro nutrient analyzer system.

BODC data processing procedures

Data from SAMS were provided in Mstar format and the data from NOC in .CSV format. The data files were converted to Microsoft Excel format and loaded into BODC's ocean database under the ORACLE Relational Database Management System without modification. Data that were considered unrealistic were flagged suspect. Metadata collected from the various data files were favoured by BODC over the metadata recorded in the cruise report logs in the JC086 cruise report.

Content of data series

Data quality report

BODC applied flags to negative silicate values at CTD cast 59 bottle 13 and CTD cast 64 bottle 17.

No problems were reported and no significant issues encountered during BODC data banking procedures.

References cited

Griffiths C. R. et al., 2013. RRS James Cook Cruise JC086, 06 May 2013 - 26 May 2013. Govan to Govan, Scotland - the Extended Ellett Line. Scottish Association for Marine Science. (Scottish Marine Institute, Oban).

Available - Cruise JC086 Internal Report

Hartman, S., J. L. Menzel and Achterberg.E., 2014. Discrete Carbon Dioxide Data Obtained During the R/V James Cook EEL_2013_JC86 Cruise Along Extended Ellett Line. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee. doi: 10.3334/CDIAC/OTG.CLIVAR_EEL_2013_JC86

The doi referenced was created prior to BODC receiving the data and is a subset of the dataset (only NOC nutrients).

Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 4: The Extended Ellett Line

The Ellett Line (begun in 1975 and since 1996 the Extended Ellett Line from Scotland to Iceland) crosses important north Atlantic Meridional Overturning Circulation (MOC) components and thus provides an additional contribution to understanding the north Atlantic response to climate change. Sustained Observation Activity (SO) 4 will repeat this section annually collecting a wide variety of physical and biogeochemical measurements, and will, to enhance the time variable component, make use of Argo floats and gliders. SO 4 will be implemented by physical, biological and chemical scientists at the National Oceanography Centre, Southampton (NOCS) and the Scottish Association for Marine Science (SAMS).

SO 4 formally contributes to the Department for Environment, Food and Rural Affairs (DEFRA)-funded Marine Environmental Change Network (MECN). Established in 2002 to coordinate and promote the collection and utilisation of marine time-series and long-term data sets, the goal of the network is to use long-term marine environmental data from around the British Isles and Ireland to separate natural fluctuations from global, regional and local anthropogenic impacts.

The specific deliverables for SO 4 are:

• A time series of the evolution of the hydrography of the northeast Atlantic, together with a more formal understanding of the causes of any changes observed
• An archived data set available to the international community via the British Oceanographic Data Centre (BODC)
• A platform for further scientific research

More detailed information on this Work Package is available at pages 15 - 16 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10

Weblink: http://www.oceans2025.org/

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JC086_CTD_C074

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

Fixed Station Information

Extended Ellett Line

The Extended Ellett Line is a hydrographic transect consisting of 64 individual fixed stations which have been occupied, typically on an annual basis, since September 1996. The Line runs from the south of Iceland, across the Iceland Basin to the outcrop of Rockall, and across the Rockall Trough to the north west coast of Scotland (see map). CTD dips and associated water sampling for the analysis of nutrients are routinely performed during each station occupation.

The Extended Ellett Line augments the original Ellett Line time series - a shorter repeated transect which encompassed those stations between Rockall and Scotland. Work on the Ellett Line was typically carried out at least once a year between 1975 and 1996.

Map of standard stations (1996-present)

Map produced using the GEBCO Digital Atlas

The white triangles indicate the nominal positions of the Extended Ellett Line stations visited since September 1996. Measurements made along the Extended Ellett Line lie within a box bounded by co-ordinates 56° N, 21° W at the south west corner and 65° N, 6° W at the north east corner.

Nominal Extended Ellett Line stations (September 1996-present)

Listed below are nominal details of the standard hydrographic stations that form the Extended Ellett Line. The majority of these stations have been sampled since the outset, although several have been added more recently.

Occupations of the Extended Ellett Line (September 1996-present)

* These cruises only surveyed the original hydrographic section between Scotland and Rockall.

Related Fixed Station activities are detailed in Appendix 2

Fixed Station Information

Ellett Line/Extended Ellett Line: Station S

Station S is one of the fixed CTD stations, which together form The Extended Ellett Line. The line lies between Iceland and the Sound of Mull (Scotland) crossing the Iceland Basin and Rockall Trough via the outcrop of Rockall. As part of this initiative, CTD dips, together with associated discrete sampling of the water column, have typically been carried out annually at this station since September 1996.

Prior to September 1996, Station S was part of a shorter repeated survey section, consisting of 35 fixed stations, known as The Ellett Line (originally termed the Anton Dohrn Seamount Section). This line incorporated those stations across the Rockall Trough and Scottish shelf between Rockall and the Sound of Mull and was visited at regular intervals (usually at least once a year) between 1975 and January 1996.

Related Fixed Station activities are detailed in Appendix 3

Fixed Station Information

Ellett Line

The Ellett Line is a hydrographic transect consisting of 35 individual fixed stations which were occupied, usually at least once a year, between 1975 and 1996. The time series is named after the scientist David Ellett, who coordinated the survey work at Dunstaffnage Marine Laboratory (DML), near Oban. The transect ran between the north west coast of Scotland to the small outcrop of Rockall, via the Anton Dohrn Seamount - a prominent bathymetric feature in the Rockall Trough (see map). STD/CTD dips and associated water sampling for the analysis of nutrients were routinely performed during each station occupation.

In 1996 the transect was lengthened to incorporate new additional fixed stations crossing the Iceland Basin from Rockall to Iceland. This transect, which is still routinely occupied annually, is now known as the Extended Ellett Line and is a collaborative effort between scientists at Dunstaffnage Marine Laboratory and the Southampton site of the National Oceanography Centre (NOC).

Map of standard stations (1975-1996)

Map produced using the GEBCO Digital Atlas

The white triangles indicate the nominal positions of the Ellett Line stations (1975- 1996). Measurements made along the Ellett Line lie within a box bounded by co-ordinates 56° 40.02' N, 13° 42.0' W at the south west corner and 57° 37.2' N, 6° 7.98' W at the north east corner.

Nominal Ellett Line stations (1975-1996)

Listed below are nominal details of the standard hydrographic stations that formed the Ellett Line between 1975 and January 1996.

History of Ellett Line occupations (1975-January 1996)

Related Fixed Station activities are detailed in Appendix 4

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: JC086_CTD_C074

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.

Appendix 2: Extended Ellett Line

Related series for this Fixed Station 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.