Metadata Report for BODC Series Reference Number 1355364


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Claire Mahaffey
Originating Organization University of Liverpool Department of Earth and Ocean Sciences (now University of Liverpool Department of Earth, Ocean and Ecological Sciences)
Processing Status banked
Project(s) Oceans 2025 Theme 10 SO11
 

Data Identifiers

Originator's Identifier PD36_10_CTD_NUTS_742:cast005
BODC Series Reference 1355364
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2010-09-28 13:13
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 53.78490 N ( 53° 47.1' N )
Longitude 3.36548 W ( 3° 21.9' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 0.9 m
Maximum Sensor Depth 19.6 m
Minimum Sensor Height 3.8 m
Maximum Sensor Height 22.5 m
Sea Floor Depth 23.4 m
Sensor Distribution Unspecified -
Sensor Depth Datum Unspecified -
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
ADEPZZ01 1 Metres DepBelowSurf Depth below surface of the water body
BOTTFLAG 1 Dimensionless C22_flag Sampling process quality flag (BODC C22)
FIRSEQID 1 Dimensionless FireSeqNo Bottle firing sequence number
NTRIAATX 1 Micromoles per litre NO2_Unfilt_ColAA Concentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
NTRZAATX 1 Micromoles per litre NO3+NO2_Unfilt_ColAA Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
NTSDAATX 1 Micromoles per litre SD_NO2 Concentration standard deviation of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
PHOSAATX 1 Micromoles per litre PO4_Unfilt_ColAA Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
ROSPOSID 1 Dimensionless RosPos Bottle rosette position identifier
SAMPRFNM 1 Dimensionless SampRef Sample reference number
SDNZAATX 1 Micromoles per litre NO3+NO2SD Concentration standard deviation of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SDPHAATX 1 Micromoles per litre SD_PO4 Concentration standard deviation of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SLCAAATX 1 Micromoles per litre SiOx_Unfilt_ColAA Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SLSDAATX 1 Micromoles per litre SD_SiO4 Concentration standard deviation of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database


Data Access Policy

Public domain data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."


Narrative Documents

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.

Deployment

Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles have a capacity between 1.7 and 30 L, while Lever Action bottles have a capacity between 1.7 and 12 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

RV Prince Madog cruise PD36_10 dissolved nutrient data series measured by DEOS

Originator's Protocol for Data Acquisition and Analysis

Samples for nutrient analyses were collected by the Department of Earth and Ocean Sciences, Liverpool University (DEOS) on a National Oceanography Centre, Liverpool (NOCL) Oceans 2025 SO11 Coastal Observatory cruise (number 72) in Liverpool Bay and the Eastern Irish Sea. The cruise ran from 28 - 29 September 2010.

Single samples were taken near-surface and near-bed from water bottle rosette sampling systems mounted on the lowered CTD during 35 CTD casts. Additionally, duplicate samples were taken near-surface and near-bed from the water bottle rosette during cast025.

The nutrient samples were collected directly from the rosette bottles into acid-washed, deionised water rinsed 125 ml high density polyethylene (HDPE) screw cap bottles. The HDPE bottles were rinsed 3 times with sample water and then filled with approximately 100 ml of sample. The bottles were then capped and labelled.

The samples were placed in a -20 °C freezer and frozen upright. The samples were transported frozen to Liverpool University for analysis. Prior to analysis, samples were defrosted in the dark and all analyses were performed within 1 week of sample collection. Analysis was carried out by splitting each single sample into triplicate sub-samples and analysing these using a Quaatro AQ2 Autoanalyzer 3 (Seal Analytical, 2006).

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. The variables supplied by the Data Originator were mapped to BODC parameter vocabularies as follows:

Originator's Parameter Units Description BODC Parameter Code Units
mean N + N µmol l -1 Concentration of nitrate+nitrite {NO 3 +NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRZAATX µmol l -1
stdev µmol l -1 Concentration standard deviation of nitrate+nitrite {NO 3 +NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SDNZAATX µmol l -1
mean silicate µmol l -1 Concentration of silicate {SiO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SLCAAATX µmol l -1
stdev µmol l -1 Concentration standard deviation of silicate {SiO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SLSDAATX µmol l -1
mean phosphate µmol l -1 Concentration of phosphate {PO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis PHOSAATX µmol l -1
stdev µmol l -1 Concentration standard deviation of phosphate {PO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SDPHAATX µmol l -1
mean nitrite µmol l -1 Concentration of nitrite {NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRIAATX µmol l -1
stdev µmol l -1 Concentration standard deviation of nitrite {NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTSDAATX µmol l -1

The data were loaded into the database by matching the sample's station identifier and depth with the information already held in the database for this cruise. Records for this cruise indicated that all near-bed samples from the CTD were taken from rosette bottle 4 and all near-surface samples were taken from rosette bottle 10.

Comments

The concentrations used to obtain one mean NO 2 sample were found by the Data Originator to be below the limits of detection of the Autoanalyzer. This sample has been flagged accordingly by BODC. In this instance, no standard deviation value was supplied by the Data Originator.

For cast025, duplicate values of concentration and standard deviation for all the measured nutrients were supplied by the Data Originator. This was both for the surface and bed samples. BODC have calculated the means of these duplicate values and stored these in our database. The duplicate values are available on request.

References

Seal Analytical, 2006. AutoAnalyzer 3 Quaatro AQ2 AACE, Seal Analytical GmbH, Werkstrasse 4, D-22844, Norderstadt, Germany


Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 11: Liverpool Bay and Irish Sea Coastal Observatory

Sustained, systematic observations of the ocean and continental shelf seas at appropriate time and space scales allied to numerical models are key to understanding and prediction. In shelf seas these observations address issues as fundamental as 'what is the capacity of shelf seas to absorb change?' encompassing the impacts of climate change, biological productivity and diversity, sustainable management, pollution and public health, safety at sea and extreme events. Advancing understanding of coastal processes to use and manage these resources better is challenging; important controlling processes occur over a broad range of spatial and temporal scales which cannot be simultaneously studied solely with satellite or ship-based platforms.

Considerable effort has been spent by the Proudman Oceangraphic Laboratory (POL) in the years 2001 - 2006 in setting up an integrated observational and now-cast modelling system in Liverpool Bay (see Figure), with the recent POL review stating the observatory was seen as a leader in its field and a unique 'selling' point of the laboratory. Cost benefit analysis (IACMST, 2004) shows that benefits really start to accrue after 10 years. In 2007 - 2012 exploitation of (i) the time series being acquired, (ii) the model-data synthesis and (iii) the increasingly available quantities of real-time data (e.g. river flows) can be carried out through Sustained Observation Activity (SO) 11, to provide an integrated assessment and short term forecasts of the coastal ocean state.

BODC image

Overall Aims and Purpose of SO 11

Measurement and Modelling Activities

More detailed information on this Work Package is available at pages 32 - 35 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10

Weblink: http://www.oceans2025.org/

References:

IACMST., 2004. The Economics of Sustained Marine Measurements. IACMST Information Document, N0.11, Southampton: IACMST, 96 pp


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2010-09-28
End Date (yyyy-mm-dd) 2010-09-28
Organization Undertaking ActivityNational Oceanography Centre, Liverpool
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPD36_10_CTD_cast005
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for PD36_10_CTD_cast005

Sample reference number Nominal collection volume(l) Bottle rosette position Bottle firing sequence number Minimum pressure sampled (dbar) Maximum pressure sampled (dbar) Depth of sampling point (m) Bottle type Sample quality flag Bottle reference Comments
446129    5.00 3 1   20.10   20.20   19.50 Niskin bottle No problem reported    
446130    5.00 4 2   20.10   20.30   19.60 Niskin bottle No problem reported    
446131    5.00 8 3    5.80    6.90    5.90 Niskin bottle No problem reported    
446132    5.00 9 4    1.40    1.50    1.00 Niskin bottle No problem reported    
446133    5.00 10 5    1.20    1.50     .90 Niskin bottle No problem reported    

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.

Other Series linked to this Data Activity - 1689075

Cruise

Cruise Name PD36/10
Departure Date 2010-09-27
Arrival Date 2010-09-30
Principal Scientist(s)Phil J Knight (National Oceanography Centre, Liverpool)
Ship RV Prince Madog

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:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

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

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain