Metadata Report for BODC Series Reference Number 2053813

• 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

Thermo Scientific HiPerTOC Total Organic Carbon analyser

A laboratory instrument designed for Total Organic Carbon (TOC) analysis in water samples. It can also be used for Total Carbon (TC), Total Inorganic Carbon (TIC), Non-Purgable Organic Carbon (NPOC) and Total Bound Nitrogen (TNb) analysis. The HiPerTOC is equipped with four different oxidation techniques for TOC analysis; High Temperature Oxidation, UV/Persulfate, UV Ultra-Pure and Ozone Promoted. It features a 63-position XYZ-sampler with two sampling needles for automated introduction of water samples into the instrument. It also features a stirrer module which ensures sample homogeneity and enables particulates with diameters up to 700 um to be analysed. It also features high and low range (dual-beam) Non-Dispersive Infra-Red (NDIR) detectors. The HiPerTOC analyser is supported by the Thermo Scientific ThEuS Sofware. The HiPerTOC analyser can be extended with a TN-CLD module to measure TOC and TNb in one run. Typical measurement ranges are from 250 - 10000 ppb. It requires an ambient temperature of 15 - 35 degC and relative humidity of 20 - 80 percent.

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/Thermo_Scientific_HiPerTOC.pdf

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.

DOC profiles (CTD bottles) for Cruise JC053

Originator's Protocol for Data Acquisition and Analysis

Sampling methodology

Water samples for determining CDOM absorption, CDOM fluorescence and DOC concentration were collected at fixed depths with Niskin bottles attached to a CTD rosette during solar noon casts. Water samples depths were determined upon features of the vertical profiles of the chlorophyll a fluorescence. At all stations following the depths were sampled: 300 m, 200 m, 100 m or Deep Chlorophyll Maximum (which ever deeper), bottom of the mixed layer, middle of the mixed layer and the water surface. Water samples for determination of CDOM absorption, fluorescence EEM and DOC concentrations underwent a two-step filtration process. The first filtration was through acid-washed Whatman glass fibre filters (GF/F, nominal pore size 0.7 µm). The water was then passed through Sartorius 0.2 µm pore cellulose membrane filters to remove fine-sized particles.

Analytical methodology

Following filtration of water samples, a total of 40 ml aliquots of filtrate were acidified with 150 µl 0.1 M HCl and stored in the dark at 5°C until laboratory analysis. Samples were shipped in the conditioned container to the Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland for estimation of the DOC concentration in the laboratory. These were done in a 'HiPerTOC' analyser (Thermo Electron Corp., The Netherlands) using UV/persulphate oxidation and non-dispersive infrared detection (Sharp 2002). Measurements of each sample, using the standard addition method (potassium hydrogen phthalate), were performed in triplicate. Quality control of DOC concentrations were performed with reference material supplied by Hansell Laboratory, University of Miami. The methodology ensured satisfactory accuracy. The quality assessment performed in previous studies in the Baltic Sea have given following results: average recovery 95%; n = 5; CRM = 44 - 46 µM C; these results = 42 - 43 µM C and precision is characterized by a relative standard deviation (RSD) of 2% (Kowalczuk et al., 2010).

References Cited

Kowalczuk P., Zablocka M., Sagan S., & Kulinski K., 2010. Fluorescence measured in situ as a proxy of CDOM absorption and DOC concentration in the Baltic Sea. Oceanologia, 52 (3), 431-471.

Sharp J. H., Carlson C. A., Peltzer E. T., Castle-Ward D. M., Savidge K. B., & Rinker K. R., 2002. Final dissolved organic carbon broad community intercalibration and preliminary use of DOC reference materials. Marine Chemistry, 77(4), 239-253.

JC053 Cruise report

Further information can be found in the JC053 Cruise report.

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:

Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 1: The Atlantic Meridional Transect (AMT)

The Atlantic Meridional Transect has been operational since 1995 and through the Oceans 2025 programme secures funding for a further five cruises during the period 2007-2012. The AMT programme began in 1995 utilising the passage of the RRS James Clark Ross between the UK and the Falkland Islands southwards in September and northwards in April each year. Prior to Oceans 2025 the AMT programme has completed 18 cruises following this transect in the Atlantic Ocean. This sustained observing system aims to provide basin-scale understanding of the distribution of planktonic communities, their nutrient turnover and biogenic export in the context of hydrographic and biogeochemical provinces of the North and South Atlantic Oceans.

The Atlantic Meridional Transect Programme is an open ocean in situ observing system that will:

• give early warning of any fundamental change in Atlantic ecosystem functionng
• improve forecasts of the future ocean state and associated socio-economic impacts
• provide a "contextual" logistical and scientific infrastructure for independently-funded national and international open ocean biogeochemical and ecological research.

The specific objectives are:

• To collect hydrographic, chemical, ecological and optical data on transects between the UK and the Falkland Islands
• To quantify the nature and causes of ecological and biogeochemical variability in planktonic ecosystems
• To assess the effects of variability in planktonic ecosystems on biogenic export and on air-sea exchange of radiatively active gases

The measurements taken and experiments carried out on the AMT cruises will be closely linked to Themes 2 and 5. The planned cruise track also allows for the AMT data to be used in providing spatial context to the Sustained Observation Activities at the Porcupine Abyssal Plain Ocean Observatory (SO2) and the Western Channel Observatory (SO10).

More detailed information on this Work Package is available at pages 6 - 9 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 JC053_CTD_CTD77s

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: JC053_CTD_CTD77s

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.