Metadata Report for BODC Series Reference Number 1354115

• 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

PO300_2 discrete inorganic nutrient samples from CTD bottles

Data originator

Tim Brand, Scottish Association for Marine Science, UK

Cruise principal scientist

Colin R Griffiths, Scottish Association for Marine Science, UK

Originator's protocols

Cruise PO300_2 had various objectives, including an occupation of the Extended Ellett Line. The cruise sailed on the 19th July 2003 from Glasgow and returned there on the 6th August 2003, with a brief stop in Ullapool on 26th July 2003.

Water samples were collected from the CTD rosette into 2 litres polythene sample bottles. Up to 12 samples were taken from each cast. From these, subsamples were passed through 25 mm diameter Whatman GF/F filters and the filtrate collected in 250 ml acid-cleansed polythene bottles. These were immediately frozen for analysis back on land. Analysis was conducted using a Lachat Quik Chem 8000 flow injection autoanalyser, with triplicates of each sample run to establish instrumental precision. Standards were prepared using deionised water.

BODC processing

The data were provided to BODC in the form of an Excel workbook. The values contained within the spreadsheet were loaded to an ORACLE Relational Database. The originator did not always note the exact rosette bottle from which each sample was drawn (just the water depth). Where multiple bottles were fired at the same depth, samples were arbitrarily assigned to one of those rosette bottles. Matlab was used to enable some basic screening of the data to take place, with negative data values being flagged suspect.

SAMS nitrate data quality warning

SAMS have notified BODC of a problem in the analytical procedure adopted for nitrate analysis on this cruise. The problem relates to the technique used to prepare the analytical standards, which results in nitrate (and consequently nitrite) values which are typically 10-15 % higher than they should be. Absolute data values should therefore be used with extreme caution.

Contents of data series

Note: BODC list values out of our database to a precision deemed appropiate to the analytical procedure adopted. This has resulted in several instances of zero values within the nitrate, nitrite and ammonium data for this cruise. Original values, as supplied by the originator, are preserved in our archive.

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters within a data cycle:

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for PO300_2_CTD_P300_CTD005

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.

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: