Metadata Report for BODC Series Reference Number 1309701


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 Naomi Greenwood
Originating Organization Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory
Processing Status banked
Project(s) Oceans 2025 Theme 10 SO11
 

Data Identifiers

Originator's Identifier PD21_10_CTD_NUTS_533:cast026
BODC Series Reference 1309701
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2010-07-08 10:01
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 53.69838 N ( 53° 41.9' N )
Longitude 3.92200 W ( 3° 55.3' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 1.5 m
Maximum Sensor Depth 1.5 m
Minimum Sensor Height 40.7 m
Maximum Sensor Height 40.7 m
Sea Floor Depth 42.2 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
AMONAAD1 1 Micromoles per litre NH4_GF/CFilt_Col Concentration of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate
BOTTFLAG 1 Dimensionless C22_flag Sampling process quality flag (BODC C22)
FIRSEQID 1 Dimensionless FireSeqNo Bottle firing sequence number
NTRIAAD1 1 Micromoles per litre NO2_GF/FFilt_ColAA Concentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate
NTRZAAD1 1 Micromoles per litre NO3+NO2_GF/FFilt_ColAA Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate
PHOSAAD1 1 Micromoles per litre PO4_GF/FFilt_ColAA Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate
ROSPOSID 1 Dimensionless RosPos Bottle rosette position identifier
SAMPRFNM 1 Dimensionless SampRef Sample reference number
SLCAAAD1 1 Micromoles per litre SiOx_GF/FFilt_ColAA Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate
 

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

Centre for Environment, Fisheries and Aquaculture Science (Cefas) data access conditions

The Centre for Environment, Fisheries and Aquaculture Science (Cefas) is an Executive Agency of the Department of Environment, Food and Rural Affairs (Defra), formerly the Ministry of Agriculture, Fisheries and Food (MAFF). It was also known previously as the Directorate of Fisheries Research (DFR). This data policy refers to data collected by the organisation under all titles.


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 PD21_10 dissolved nutrients measured by Cefas

Originator's Data Processing

Samples for nutrient analyses were collected by the Centre for Environment, Fisheries and Aquaculture Science (Cefas) on a National Oceanography Centre, Liverpool (NOC) [previously the Proudman Oceanographic Laboratory] Oceans 2025 SO11 cruise (number 70) in Liverpool Bay. The cruise took place from 07 - 08 July 2010. Single samples were collected near-surface from water bottle rosette sampling systems mounted on the lowered CTD during 13 casts.

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).

Processing Undertaken by BODC

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
TOxN µmol l -1 Concentration of nitrate+nitrite {NO 3 +NO 2 } per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis NTRZAAD1 µmol l -1
NO2 µmol l -1 Concentration of nitrite {NO 2 } per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis NTRIAAD1 µmol l -1
Si µmol l -1 Concentration of silicate {SiO 4 } per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis SLCAAAD1 µmol l -1
PO4 µmol l -1 Concentration of phosphate {PO 4 } per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis PHOSAAD1 µmol l -1
NH4 µmol l -1 Concentration of ammonium {NH 4 } per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis AMONAAD1 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. The surface samples were sourced from rosette bottle 11 for each cast, with the exception of cast013 where the source of the sample was rosette bottle 12.

Comments

The Data Originator found that the combined NO 3 +NO 2 concentrations for 10 of the thirteen casts were below the limit of detection of the Skalar analyser. BODC have flagged these data accordingly.

References

Kirkwood,D.S., 1991. 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.


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) 2010-07-08
End Date (yyyy-mm-dd) 2010-07-08
Organization Undertaking ActivityNational Oceanography Centre, Liverpool
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPD21_10_CTD_cast026
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for PD21_10_CTD_cast026

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
446062    5.00 3 1   38.60   38.70   37.90 Niskin bottle No problem reported    
446063    5.00 4 2   38.70   38.90   38.00 Niskin bottle No problem reported    
446064    5.00 8 3    6.90    7.00    6.40 Niskin bottle No problem reported    
446065    5.00 9 4    1.90    2.00    1.50 Niskin bottle No problem reported    
446066    5.00 10 5    2.00    2.00    1.50 Niskin bottle No problem reported    
446067    5.00 11 6    1.90    2.10    1.50 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 - 1676661 1691031

Cruise

Cruise Name PD21/10
Departure Date 2010-07-07
Arrival Date 2010-07-08
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