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Metadata Report for BODC Series Reference Number 1270255


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country Netherlands
Originator Dr Jo Suijlen
Originating Organization Rijkswaterstaat
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Provess
 

Data Identifiers

Originator's Identifier MT0499_CTD_NUTS_161:CTD079
BODC Series Reference 1270255
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1999-04-25 01:07
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 52.30933 N ( 52° 18.6' N )
Longitude 4.29217 E ( 4° 17.5' E )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 2.1 m
Maximum Sensor or Sampling Depth 17.0 m
Minimum Sensor or Sampling Height 1.5 m
Maximum Sensor or Sampling Height 16.4 m
Sea Floor Depth 18.5 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
AMONAADZ1Micromoles per litreConcentration of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
NTRIAADZ1Micromoles per litreConcentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate
NTRZAADZ1Micromoles per litreConcentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate
PHOSAADZ1Micromoles per litreConcentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate
SAMPRFNM1DimensionlessSample reference number
SLCAAADZ1Micromoles per litreConcentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate

Definition of BOTTFLAG

BOTTFLAGDefinition
0The sampling event occurred without any incident being reported to BODC.
1The filter in an in-situ sampling pump physically ruptured during sample resulting in an unquantifiable loss of sampled material.
2Analytical 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.
3The 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.
4During 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.
5Water was reported to be escaping from the bottle as the rosette was being recovered.
6The bottle seals were observed to be incorrectly seated and the bottle was only part full of water on recovery.
7Either 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).
8There is reason to doubt the accuracy of the sampling depth associated with the sample.
9The bottle air vent had not been closed prior to deployment giving rise to a risk of sample contamination through leakage.

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 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.

Dissolved inorganic nutrient data series for cruise Mitra MT0499

Document History

Converted from CDROM documentation.

Data Originator

Jo Suijlen, National Institute for Coastal and Marine Management, RIKZ, The Netherlands.

Content of data series

Parameter Unit Parameter code Number of samples Number of stations Comments
Ammonium µmol l-1 AMONAADZ 800 166 CTD none
Nitrate+Nitrite µmol l-1 NTRZAADZ 800 166 CTD none
Nitrite µmol l-1 NTRIAADZ 800 166 CTD none
Phosphate µmol l-1 PHOSAADZ 800 166 CTD none
Silicate µmol l-1 SLCAAADZ 800 166 CTD none

CTD= CTD-Rosette sampling

Sampling strategy and methodology

Water samples for nutrient analysis were collected from 6 depths in the water column on every CTD cast using the CTD-rosette water sampler. Samples were filtered through Whatman GF/C filters immediately after sampling, and stored in polyethylene bottles prior to analysis. Nutrients were analysed with a Continuous Flow Analyzer System using standard colorometric autoanalysis methods.

In addition, measurements of dissolved inorganic nutrients (ammonium, nitrite, nitrate, silicate, phosphate) were made during the cruise by the Centre d' Océanologie de Marseille (C. Grenz and co-workers) on bottom water collected with the rosette sampler. These data were collected in the context of sediment flux studies and the analytical method was similar to that used for sediment cores interstitial water analysis (GF/F filtration and autoanalysis). Further details regarding these data are available from the data documentation mt0499sed.Dissolved inorganic nutrients were also measured by the Dunstaffnage Marine Laboratory (K. Jones and co-workers) on samples collected with an Interfacial Sampler. Further information is available from the data documentation mt0499ifs.

Sample analysis was performed under the supervision of Principal Chemical Analyst Wim Schreurs from the RIKZ laboratory, Middelburg, The Netherlands.

BODC processing

In order to standardise parameter units with that held in the BODC Parameter Dictionary, all nutrient concentrations were converted from mg N, mg P and mg Si per litre to µmol l-1 by multiplying their original values by 1000 and dividing by their respective atomic weights (14.01 for N, 30.97 for P and 28.09 for Si). The data were then loaded into a database under the ORACLE Relational Database Management System without further modification.

Comments on data quality

None to report.


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) 1999-04-25
End Date (yyyy-mm-dd) 1999-04-25
Organization Undertaking ActivityScottish Association for Marine Science
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierMT0499_CTD_CTD079
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for MT0499_CTD_CTD079

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
383333          2.10    2.20    2.10 Niskin bottle No problem reported    
383334          5.20    5.30    5.20 Niskin bottle No problem reported    
383335          8.00    8.10    8.00 Niskin bottle No problem reported    
383336         11.10   11.20   11.10 Niskin bottle No problem reported    
383337         14.00   14.10   13.90 Niskin bottle No problem reported    
383338         17.10   17.30   17.00 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 MT0499
Departure Date 1999-04-19
Arrival Date 1999-04-30
Principal Scientist(s)S Martyn Harvey (Scottish Association for Marine Science)
Ship RV Mitra

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