Metadata Report for BODC Series Reference Number 2109813

• 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

Exeter Analytical Model CE-440 Rapid Analysis Elemental Analyser

The 440 is a fully automated elemental analyser that is capable of analyzing Carbon, Hydrogen, Nitrogen, Oxygen and Sulphur. The CE-440 uses a thermal conductivity detection method for measuring carbon, nitrogen and hydrogen after combustion and reduction. This method produces rapid and highly accurate measurements over a wide range of elemental compositions, with most measurements completed in less than five minutes. The CE-440 has a 64-sample carousel and uses Windows based software with data storage, statistical analysis, flexible report generation and continuous diagnostic and automatic maintenance alerts, controls and monitors all instrument functions.

The instrument allows complete control of combustion parameters and continuous measurement of the steady state combustion process ensuring a high degree of accuracy and precision. It has both static and dynamic combustion and the horizontal furnace allows for automatic removal of the residue from each sample after analysis.

Specifications

Further information can be found in the manufacturer's brochure.

Non-toxic (underway) sea water supply

A source of uncontaminated near-surface (commonly 3 to 7 m) seawater pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the non-toxic supply. The system is also referred to as the underway supply.

AMT22 (JC079) RRS James Cook surface underway sampled Particulate Organic Carbon (POC) and Particulate Organic Nitrogen (PON)

Originator's Protocol for Data Acquisition and Analysis

Discrete samples were collected from the ship's underway seawater supply. For each of these underway samples the following parameters were determined:

• Phytoplankton carbon biomass
• Flow-cytometric analysis
• Particle size distribution
• Particulate organic carbon (Behrenfeld and Boss 2006)
• Phytoplankton pigments (High Performance Liquid Chromatography)

Discrete samples were collected from the ship's underway seawater supply (~5m depth) by filling up 2L bottles (round-robbin style) and filtering 3 volumes (actual volumes differed between samples) onto pre-combusted GF/F filters. Filters were wrapped in foil and frozen in liquid nitrogen until analysis. Samples were measured for particulate organic nitrogen and particulate organic carbon using an Exeter Analytical Model 440 CHN/O/S Elemental Analyzer in the Behrenfeld lab using standard methods. A linear regression of C or N concentration versus volume filtered was created and the corresponding filter blank for each sample was used. The intercept blank was subtracted from the C or N value, then divided by volume and averaged for the three measurements. Measurements with R^2 <0.9 were removed.

References Cited

Behrenfeld, M.J. and Boss, E. 2006. Beam attenuation and chlorophyll concentration as alternative optical indices of phytoplankton biomass, J. Mar. Res., 64, 431-451.

Instrumentation Description

Exeter Analytical Model 440 CHN/O/S Elemental Analyzer

BODC Data Processing Procedures

Data were received in Excel file format and archived in the BODC archive under accession number OPP140092. The data were loaded to the database using established BODC data banking procedures. Sample metadata (Sample ID, latitude, longitude, date, time (GMT) and year day were provided and checked against information held in the database. Parameter codes defined in the BODC parameter dictionary were assigned to the variables. The data for POC and PON were converted from ug L^-1 to µmol L^-1. This was achieved by dividing by 12 for carbon (atomic mass of carbon). The same was done for PON by dividing by 14 (atomic mass of Nitrogen) Data were loaded to BODC's database and a table mapping these parameters is given below:

Data Quality Report

BODC were not advised of specific quality checks carried out by the data originators. There were no stand-out values in the sample data provided to the BODC.

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

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: