Metadata Report for BODC Series Reference Number 1623574

• 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.

Extracted chlorophyll-a measurements from non-toxic underway supply samples collected during AMT22 (JC079)

Originator's Protocol for Data Acquisition and Analysis

Samples were taken from the non-toxic underway supply to provide a calibration for the continuous fluorometer measurements. During the cruise 143 samples were collected from the non-toxic underway system and processed for extracted chl-a measurement.

250 ml samples of seawater collected from the non-toxic supply were filtered through 47 mm diameter 0.2 µm polycarbonate filters. The chlorophyl-a was then extracted from the filters with 10ml 90% acetone for 24 hours while samples were stored in a freezer. The concentrations were then determined fluorometrically.

Instrumentation Description

Turner Designs Trilogy fluorometer with a non-acidified chl module (CHL NA #046) fitted

BODC Data Processing Procedures

Data were submitted on the Post-Cruise Archive and archived under BODC's accession number BOD120217. Sample metadata (date, time (UT), latitude and longitude) were provided and loaded to the database.

No unit conversion was necessary as the units the data were supplied in the files matched the units for the parameter codes in the BODC Parameter Dictionary.

A parameter mapping table is provided below;

Data Quality Report

There were no data quality issues reported at then end of the cruise.

These data were updated on 14/05/2014. A cross calibration between AMT cruises 20-23 using the same bench fluorometer revealed a correction factor needed to be applied to the discrete chl-a data for AMT22. Possibly a problem with the standard chl-a solution used for calibration of the bench fluorometer during the cruise. This correction has now been applied to these data. The correction applied was:

Corrected Chl-a = 0.7886 * Chl-a - 0.0012

Problem Report

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: