Metadata Report for BODC Series Reference Number 1661207
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 |
|---|---|
| 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.
Phytoplankton pigment concentration data series for cruise Dana D1198
Document History
Converted from CDROM documentation.
Data Originator
Andy Visser, Danish Institute for Fisheries Research (DIFRES), Charlottenlund, Denmark.
Content of data series
| Parameter | Unit | Parameter code | Number of samples | Number of stations | Comments |
|---|---|---|---|---|---|
| Chlorophyll a | µg l-1 | CPHLSPP3 | 66 | 17 CTD | none |
| Phaeopigment a | µg l-1 | PHAESPP3 | 55 | 17 CTD | none |
CTD= CTD-Rosette water column sampling station.
Sampling strategy and methodology
Water samples for the determination of phytoplankton pigment concentrations were collected at selected depths (usually 3-4) during the upcast of the CTD cast. About 4 litres of seawater were filtered onto GF/C filters under 0.2 bar vacuum. The filters were then extracted in the dark in 5 ml, 90% acetone. Determination of pigment concentration was made following the Lorenzen method (Strickland, Parsons 1972). The spectral properties of the samples were measured against 90% acetone blank using a Perkin-Elmer 554 UV-VIS spectrophotometer at wavelengths of 750, 665, 664, 647, 630, 510 and 480 nm before and after addition of hydrochloric acid.
BODC processing
The data were loaded into a database under the ORACLE Relational Database Management System without modification.
Comments on data quality
A number of analysed samples (n=13) exhibited suspiciously low/high value relative to that expected from their associated fluorescence profile and from the vertical distribution of chlorophyll concentration observed at most stations during this cruise as well as during concomitant PROVESS cruises (CH140 and PE125). These data (chlorophyll and phaeopigment concentrations) were flagged as suspect in the database (symbolised by an 'M' flag).
Reference
Strickland JDH, Parsons TR (1972) A practical handbook of seawater analysis. Bull. Fish. Res. Bd. Can., vol. 167, pp. 1-310.
Project Information
PROcesses of Vertical Exchange in Shelf Seas (PROVESS)
Introduction
PROVESS was an interdisciplinary study of the vertical fluxes of properties through the water column and the surface and bottom boundary layers. The project was funded by the European Community MAST-III programme (MAS3-CT97- 0159) and ran from March 1998 to May 2001.
Scientific Rationale
PROVESS was based on the integration of experimental, theoretical and modelling studies with the aim of improving understanding and quantification of vertical exchange processes in the water column, in particular in the surface and benthic boundary layers and across the> pycnocline. PROVESS also explored mechanisms of physical-biological coupling in which vertical exchanges and turbulence significantly affect the environmental conditions experienced by the biota with particular reference to aggregation, flocculation, sedimentation and trophic interactions.
Fieldwork
The experimental phase of the project was carried out at two contrasting sites in the North Sea: the northern North Sea site (NNS) and the southern North Sea site (SNS).
The two sites had the following characteristics:
| SNS | NNS | |
|---|---|---|
| Position | 52° 15.0' N, 4° 17.0' E | 59° 20.0' E, 1° 00.0' E |
| Time of year | April-May | September-November |
| Water depth (m) | 16 | 100 |
| M2 max amplitude (m s-1) | 0.75 | 0.15 |
| Max current (m s-1) | 1.0 | 0.6 |
| Delta T (deg C) | mixed | 7-1 |
| Thermocline depth (m) | mixed | 35-100 |
| Delta S | 1 | small |
| Halocline depth (m) | 5-10 | cf. thermocline depth |
| Max wind speed (m s-1) | 20 | 25 |
| Max wave height (m) | 5 | 10 |
| Max wave period (s) | 8 | 10 |
| Internal motion | No | Yes |
| Sediment | muddy-sand | muddy-sand |
| Biology | eutrophic | oligotrophic |
At both locations measurements were concentrated at a central position with additional measurements being made to estimate horizontal gradients. Moored instruments (including current meters, temperature and pressure sensors, fluorometers, transmissometers, nutrient analysers and meteorological sensors) were deployed between 7 September and 5 November 1998 at the NNS and between 29 March and 25 May 1999 at the SNS. Each experiment was supported by intensive measurement series made from oceanographic ships and involving turbulence dissipation profiler CTD, particle size profilers, optical profilers, benthic sampling and water bottle sampling.
Details of the cruises were as follows:
| Site | Ship (nationality) | Cruise Mnemonic | Date |
|---|---|---|---|
| NNS | Valdivia (GER) | VA174 | 5 - 17 Sep 1998 |
| Dana (DK) | D1198 | 14 - 26 Oct 1998 | |
| Pelagia (NL) | PE125 | 19 - 30 Oct 1998 | |
| Challenger (UK) | CH140 | 22 Oct - 9 Nov 1998 | |
| SNS | Pelagia (NL) | PE135 | 29 Mar - 9 Apr 1999 |
| Mitra (NL) | MT0499 | 19 - 30 Apr 1999 | |
| Belgica (BE) | BG9912 | 17 - 21 May 1999 |
Data Activity or Cruise Information
Data Activity
| Start Date (yyyy-mm-dd) | 1998-10-20 |
| End Date (yyyy-mm-dd) | 1998-10-20 |
| Organization Undertaking Activity | Danish Institute for Fisheries Research (now Technical University of Denmark, National Institute of Aquatic Resources) |
| Country of Organization | Denmark |
| Originator's Data Activity Identifier | D1198_CTD_CTD25 |
| Platform Category | lowered unmanned submersible |
BODC Sample Metadata Report for D1198_CTD_CTD25
| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 382898 | 5.00 | 2.20 | 3.50 | 2.80 | Niskin bottle | No problem reported | ||||
| 382899 | 5.00 | 83.80 | 85.10 | 83.60 | Niskin bottle | No problem reported | ||||
| 383102 | 5.00 | 17.40 | 18.10 | 17.60 | Niskin bottle | No problem reported | ||||
| 383103 | 5.00 | 32.80 | 33.60 | 32.90 | Niskin bottle | No problem reported | ||||
| 383104 | 5.00 | 42.90 | 43.70 | 42.90 | Niskin bottle | No problem reported | ||||
| 383105 | 5.00 | 64.10 | 64.60 | 63.70 | 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.
Cruise
| Cruise Name | D1198 |
| Departure Date | 1998-10-14 |
| Arrival Date | 1998-10-26 |
| Principal Scientist(s) | André W Visser (Danish Institute for Fisheries Research) |
| Ship | RV Dana |
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 |
| B | nominal value |
| Q | value below limit of quantification |
