Metadata Report for BODC Series Reference Number 2106864

• 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

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.

AMT19 (JC039) pigment composition by HPLC analysis from surface underway samples

Data Acquisition and Analysis

Fresh seawater samples from the ship's non-toxic supply were collected during the cruise. 2-4 L of seawater were filtered through Whatman GF/F filters and the filters stored at -80°C. HPLC analysis was carried out after Van Heukelem and Thomas (2001).

References Cited

Van Heukelem, L. and Thomas, C. S. (2001). Computer-assisted high performance liquid chromatography method development with applications to the isolation and analysis of phytoplankton pigments, Journal of Chromatography A, 910, 31-49.

Instrumentation Description

Section not relevant.

BODC Data Processing Procedures

Data were submitted to BODC in the SeaBASS text format and saved to the archive with reference PML110038. The file was provided to BODC with date, time (in GMT), latitude, longitude and sample depth as metadata.

Sample metadata were checked against information held in the cruise report - there was one discrepancy where all sample depths provided were 5m except one which was provided as 0m, this was confirmed as a typo with the data originator. The metadata were loaded to the database.

Parameter codes defined in BODC parameter dictionary were assigned to the variables as shown in the table below. The data were provided in mg m^-3 units and these were converted to ng l^-1 for all parameters but chlorophyll-a. Three parameters were not loaded to the database (Tot chl-a, Tot chl-b and Tot chl-c) as these were derived by aggregating other parameters in the dataset. These parameters can be derived from the following parameters:

Tot_Chl_a = Chl_a + DV_Chl_a + Chlide_a

Tot_Chl_b = Chl_b + DV_Chl_b

Tot_Chl_c = Chl_c1c2 + Chl_c3

There were 18 sample events with data from replicate samples provided and these data were averaged and the mean and standard deviation values loaded to the database for each sampling event.

Data loaded into BODC's database according to protocols.

Data Quality Report

The data originator also confirmed that values provided in the file of 0.001 mg m^-3 were the detection limit. All these values have been flagged accordingly with the BODC flag for data below the detection limit.

BODC were not advised by the data originator of any further QC having taken place.

Problem Report

This section is not relevant to this data set.

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: