Dissolved nutrient data series measured by CEFAS on POL Coastal Observatory cruise 6, RV Prince Madog cruise PD10_03
Data Originator
Naomi Greenwood, CEFAS, Lowestoft
Content of data series
| Parameter | Units | Parameter code | CTD Samples |
|---|---|---|---|
| Total NO3 and NO2 concentration | µmol l -1 | NTRZAAD1 | 6 |
| Phosphate concentration | µmol l -1 | PHOSAAD1 | 6 |
| Silicate concentration | µmol l -1 | SLCAAAD1 | 6 |
| Ammonia concentration | µmol l -1 | AMONAAD1 | 6 |
| Nitrite (NO2) concentration | µmol l -1 | NTRIAAD1 | 6 |
Originator's Protocol
Samples for nutrient analyses were collected from water bottle rosette sampling systems mounted on the lowered CTD. Samples were collected near-surface from a total of 6 CTD stations. Each sample was passed through a Whatman GF/F filter and preserved with mercuric chloride to give a final concentration of 20 µg l -1 .
Samples were stored refrigerated at -18° C until analysed by a Skalar continuous flow analyzer, following Kirkwood (1996).
BODC Processing
The data were supplied to BODC as an Excel spreadsheet. This was converted to an ASCII format file for loading into the BODC archive. Methodology and units were checked against information held in the BODC parameter dictionary and an appropriate parameter code was attributed to each variable. The file's data and metadata fields were then checked prior to loading into a database.
The data were loaded into the database under the Oracle Relational Database Management System by matching the sample's station identifier and depth with the information already held in the database for this cruise. Where the data supplied included multiple replicates for each station, the mean value and standard deviation were loaded into the database. For single samples, the data were loaded without further modification.
Comments on data quality and outstanding issues
There is a '<' flag on the quoted surface value for ammonia concentration obtained during cast C01. This indicates that the real value is below the limit of detection. The detection limit is the quoted value (0.1 µmol l -1 in this instance).
References
Kirkwood, D. S. 1996. Nutrients: practical notes on their determination in seawater. ICES Techniques in Marine Environmental Sciences, no 17. International Council for the Exploration of the Seas, Copenhagen, 23 pp.
Conditions of Use
CEFAS Disclaimer:
"Reproduction of this material is limited to academic and educational uses only and not for any commercial purposes without permission from CEFAS. The data are provided "as is" and in no event shall CEFAS be liable for any damages, including, without limitation, any disruption, damage and/or loss to your data or computer system that may occur while using this site or data. CEFAS makes no warranty, express or implied, including the warranties of merchantability and fitness for a particular purpose; nor assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any data, information, apparatus, product, or process disclosed; nor represents that its use would not infringe the rights of any third party."
The Data Originator must be informed that the supply has occurred.
Due acknowledgement of the Originator and the Originator's Institute is made by the receiver in any product using the data.
No commercial gain ensues from usage of the data.
