Metadata Report for BODC Series Reference Number 1315012
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
Data Description |
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Data Identifiers |
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Time Co-ordinates(UT) |
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Spatial Co-ordinates | |||||||||||||||||||||||||||||||||||||||||||||
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Parameters |
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Definition of BOTTFLAG | |||||||||||||||||||||||||||||||||||||||||||||
BOTTFLAG | Definition |
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0 | The sampling event occurred without any incident being reported to BODC. |
1 | The filter in an in-situ sampling pump physically ruptured during sample resulting in an unquantifiable loss of sampled material. |
2 | Analytical evidence (e.g. surface water salinity measured on a sample collected at depth) indicates that the water sample has been contaminated by water from depths other than the depths of sampling. |
3 | The feedback indicator on the deck unit reported that the bottle closure command had failed. General Oceanics deck units used on NERC vessels in the 80s and 90s were renowned for reporting misfires when the bottle had been closed. This flag is also suitable for when a trigger command is mistakenly sent to a bottle that has previously been fired. |
4 | During the sampling deployment the bottle was fired in an order other than incrementing rosette position. Indicative of the potential for errors in the assignment of bottle firing depth, especially with General Oceanics rosettes. |
5 | Water was reported to be escaping from the bottle as the rosette was being recovered. |
6 | The bottle seals were observed to be incorrectly seated and the bottle was only part full of water on recovery. |
7 | Either the bottle was found to contain no sample on recovery or there was no bottle fitted to the rosette position fired (but SBE35 record may exist). |
8 | There is reason to doubt the accuracy of the sampling depth associated with the sample. |
9 | The bottle air vent had not been closed prior to deployment giving rise to a risk of sample contamination through leakage. |
Definition of Rank |
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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 and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.
RV Prince Madog cruise PD37_08 dissolved nutrients measured by CEFAS
Originator's Protocol for Data Acquisition and Analysis
Samples for nutrient analyses were collected by the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) on a Proudman Oceanographic Laboratory (POL) Oceans 2025 SO11 cruise (number 58) in Liverpool Bay. The cruise ran from 10 to 11 December 2008. Single samples were collected near-surface from water bottle rosette sampling systems mounted on the lowered CTD during 12 CTD 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).
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 | Comments |
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TOXN | µmol l-1 | Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | NTRZAAD1 | µmol l-1 | None |
NO2 | µmol l-1 | Concentration of nitrite {NO2} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | NTRIAAD1 | µmol l-1 | None |
SIO4 | µmol l-1 | Concentration of silicate {SiO4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | SLCAAAD1 | µmol l-1 | None |
PO4 | µmol l-1 | Concentration of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | PHOSAAD1 | µmol l-1 | None |
NH4 | µmol l-1 | Concentration of ammonium {NH4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | AMONAAD1 | µmol l-1 | None |
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 indicated that samples were sourced from different rosette bottles, depending on cast. The near-surface samples from all casts except C002 and C003 were sourced from rosette bottle 9. For casts C002 and C003, the source of the data was bottle 10.
Comments
There is a '<' flag on the quoted value of ammonium concentration for cast C024. This flag indicates that the real value is below the limit of detection. The detection limit is the quoted value (0.1 µmol l-1).
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.
Overall Aims and Purpose of SO 11
- To continue and enlarge the scope of the existing coastal observatory in Liverpool Bay to routinely monitor the northern Irish Sea
- To develop the synthesis of measurements and models in the coastal ocean to optimize measurement arrays and forecast products. Driving forward shelf seas' operational oceanography with the direct objective of improving the national forecasting capability, expressed through links to the National Centre for Ocean Forecasting (NCOF)
- To exploit the long time-series of observations and model outputs to: a) identify the roles of climate and anthropogenic inputs on the coastal ocean's physical and biological functioning (including impacts of nutrient discharges, offshore renewable energy installations and fishing activity) taking into consideration the importance of events versus mean storms / waves, river discharge / variable salinity stratification / horizontal gradients; b) predict the impacts of climate change scenarios; and c) provide new insights to Irish Sea dynamics for variables either with seasonal cycles and interannual variability, or which show weak or no seasonal cycles
- To provide and maintain a 'laboratory' within which a variety of observational and model experiments can be undertaken (Oceans 2025 Themes 3, 6, 8, 9), including capture of extreme events
- Demonstrate the value of an integrated approach in assessment and forecasting
- Demonstrate the coastal observatory as a tool for marine management strategies through collaboration with the Environment Agency (EA), Department for Environment, Food and Rural Affairs (DEFRA), Joint Nature Conservation Commmittee (JNCC), English Nature (EN), Department of Agriculture and Rural Development (DARD), and Local Authorities, providing management information pertinent to policy (e.g. Water Framework Directive)
Measurement and Modelling Activities
- East Mooring Site: Bottom frame with full suite of physical measurements (high frequency Acoustic Doppler Current Profiler (ADCP), conductivity, temperature, turbidity and fluorescence), a Centre for Environment, Fisheries and Aquaculture Science (CEFAS) directional wavebuoy, and a CEFAS Smartbuoy collecting surface properties including salinity, temperature, turbidity, nutrients, irradiance and chlorophyll. All transmit data in real-time via Orbcomm. The Smartbuoy also collects daily water samples.
- West Mooring Site: Bottom frame with full suite of physical measurements (high frequency ADCP, conductivity, temperature, turbidity and fluorescence), CEFAS Smartbuoy.
- Spatial Survey: Four - six week intervals (determined by biofouling of optical sensors). Spatial surveys comprise of vertical profiles of CTD, suspended particulate material (SPM), some bed sediment sampling and surface and bed nutrients, phytoplankton, zooplankton.
- Ferry: The Birkenhead - Belfast ferry samples near surface (5 m depth) temperature, salinity, turbidity, chlorophyll, with data transmitted by Orbcomm. The route is scientifically varied passing through six completely different hydrodynamic regions, which significantly impact on their ecological function.
- Tide gauges: Real-time data are obtained from tide gauges operated by Mersey Docks and Harbour Company (MDHC) and the UK tide gauge network.
- Satellite imagery: Weekly composite satellite data, Advanced Very High Resolution Radiometer (AVHRR) sea surface temperature (SST) and ocean colour (chlorophyll and suspended sediment), are provided by the Remote Sensing Data Analysis Service (RSDAS) based at Plymouth Marine Laboratory (PML).
- HF radar: A phased array HF radar system (a 12-16MHz WERA HF radar) measuring surface currents and waves with maximum range 75km at a resolution of 4km for sea surface currents and for 2-D wave spectra.
- Meteorology station: With web camera, located on Hilbre Island at the mouth of the Dee Estuary
- Operational models: The Coastal Observatory uses Proudman Oceanographic Laboratory Coastal Ocean Modelling System (POLCOMS), which is part of Oceans 2025 Theme 9.
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
Cruise
Cruise Name | PD37/08 |
Departure Date | 2008-12-10 |
Arrival Date | 2008-12-11 |
Principal Scientist(s) | Phil J Knight (Proudman Oceanographic Laboratory) |
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 |
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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 |
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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 |
B | nominal value |
Q | value below limit of quantification |