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Metadata Report for BODC Series Reference Number 2260676


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 Jon Barnes
Originating Organization Newcastle University Department of Marine Science and Coastal Management (now Newcastle University School of Marine Science and Technology)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) LOIS River-Atmosphere-Coast Study (RACS)
 

Data Identifiers

Originator's Identifier CH118C_CTD_CH4X_198:CTD1
BODC Series Reference 2260676
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1995-04-28 07:55
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 55.15676 N ( 55° 9.4' N )
Longitude 1.42518 W ( 1° 25.5' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 4.7 m
Maximum Sensor or Sampling Depth 36.1 m
Minimum Sensor or Sampling Height 4.5 m
Maximum Sensor or Sampling Height 35.9 m
Sea Floor Depth 40.6 m
Sea Floor Depth Source PEVENT
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Unspecified -
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
CH4CGCXX1Nanomoles per litreConcentration of methane {CH4 CAS 74-82-8} per unit volume of the water body [dissolved plus reactive particulate phase] by gas chromatography
CH4SGCXX1PercentSaturation of methane {CH4 CAS 74-82-8} in the water body [dissolved plus reactive particulate phase] by computation from concentration
SAMPRFNM1DimensionlessSample reference number

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

Open 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.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."


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.

Trace Gases for cruises RRS Challenger CH118C and RV Sea Vigil SV27B and SV27D

Document History

Converted from CDROM documentation

Content of data series

CH4CGCXX Dissolved methane
Gas chromatography
Nanomoles per litre
CH4SGCXX Methane saturation
Computed from dissolved CH4, temperature and salinity
Per cent
DCOXGCXX Dissolved carbon monoxide
Gas chromatography
Nanomoles per litre
DMSXGCD4 Dissolved dimethylsulphide (DMS)
Trap/purge gas chromatography (Millipore pre-filtered)
Nanomoles per litre
DN2OGCTX Dissolved nitrous oxide
Gas chromatography
Nanomoles per litre
SCOXGCXX Carbon monoxide saturation
Computed from dissolved CO, temperature and salinity
Per cent
SN2OGCTX Nitrous oxide saturation
Computed from dissolved N2O, temperature and salinity
Per cent

Data Originator

Dr Jon Barnes, University of Newcastle, UK.

Sampling strategy and methodology

Water samples were taken from either CTD water bottles or the ship's non-toxic supply using techniques designed to minimise contamination and degassing. Methane and nitrous oxide were determined simultaneously using a high precision, shower-head equilibrated gas chromatographic technique. Analyses were carried out on board Challenger and as soon as possible after docking for the Sea Vigil cruises.

References

Law, C.S., Sjoberg, T.N. and Ling, R.D., in press. Carbon monoxide cycling and atmospheric flux emission in a seasonal study of the Scheldt Estuary. Biogeochemistry

Sjoberg, T.N., 2000. The distribution and cycling of dissolved carbon monoxide in estuarine, coastal and shelf break environments. Ph.D. Thesis University of East Anglia 260 p.

Weisenburg, D.A. and Guinasso, N.L., 1979. Equilibrium solubilities of methane, carbon monoxide and hydrogen in water and seawater. J. Chem and Engin. Data, 24, 356-360.


Project Information

LOIS River-Atmosphere-Coast Study (LOIS - RACS)

Introduction

The Land-Ocean Interaction Study (LOIS) was a NERC research programme designed to study processes in the coastal zone. The Rivers, Atmosphere and Coasts Study (RACS) was a major component of LOIS that looked at land-sea interactions in the coastal zone and the major exchanges (physical, chemical and biological) between rivers and estuaries and the atmosphere. The study focused on the east coast of the UK from the Wash to the Tweed.

RACS included several sub-components

  • BIOTA - A study of salt marshes of the Humber and Wash
  • RACS (A) - An atmospheric chemistry study looking at air mass changes from the Wash into East Anglia
  • RACS (C) - A study of the estuaries, coasts and coastal waters between Great Yarmouth and Berwick upon Tweed.
    1. The coastal oceangraphic survey
    2. The Humber estuarine study
    3. The Tweed estuarine study
    4. The Holderness experiment
  • RACS (R) - A study of rivers that drain into the North Sea

RACS (A) was coordinated by the University of East Anglia and RACS (C) by the Plymouth Marine Laboratory.

RACS (A)

The bulk of the RACS (A) data set was collected during two field campaigns in the winter (October/November) of 1994 and the summer (May/June) of 1995. During these campaigns data were collected continuously from the University of East Anglia Atmospheric Observatory at Weybourne on the north Norfolk coast. An instrumented vessel was stationed offshore to provide a second sampling site to allow changes in a given air mass to be monitored. The Imperial College Jetstream research aircraft made one flight during each campaign to provide a link between the two surface stations. The Jetstream made four additional flights in 1996 and 1997.

RACS (C)

The coastal oceanographic survey

The coastal oceanographic data set was collected during a series of 17 RRS Challenger cruise legs. Most cruises covered two survey grids. One from Great Yarmouth to the Humber designed around the distribution of the sandbanks and a second simple zig-zag grid from the Humber to Berwick on Tweed. A large number of anchor stations, usually over one or two tidal cycles, were worked in the area of the Humber mouth or the Holderness coast.

The Humber estuarine study

The Humber estuarine data set was collected during a series of 33 campaigns on the Environment Agency vessels Sea Vigil and Water Guardian in the Humber, Trent and Ouse river systems at approximately monthly intervals between June 1993 and December 1996. Each campaign consisted of two or three one-day cruises. The tracks covered the estuary from the tidal limits of both Trent and Ouse to Spurn Point. Instrumental and sample data are available from a series of fixed stations that were sampled during every campaign.

The Tweed estuarine study

The Tweed estuarine data set was collected during a series of 13 campaigns using RV Tamaris in association with a rigid inflatable vessel at approximately monthly intervals between July 1996 and July 1997. Each campaign covered the tidal reaches of the River Tweed.

The Holderness experiment

The Holderness Experiment was designed to monitor the process of sediment transport along the Holderness coastline. It consisted of three moored instrument deployments during the winters of 1993-1994, 1994-1995 and 1995-1996. Mooring platforms were deployed at eight stations along two lines off the Holderness coast. A northerly and a southerly line of four stations each were used (N1 - N4 and S1 to S4) with the lowest numbers being inshore. Both lines were approximately perpendicular to the coast, although the S4 station lay to the south of the S line, off Spurn Head.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1995-04-28
End Date (yyyy-mm-dd) 1995-04-28
Organization Undertaking ActivityPlymouth Marine Laboratory
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierCH118C_CTD_CTD1
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for CH118C_CTD_CTD1

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
367388   10.00       36.30   37.40   36.10 Niskin bottle No problem reported    
367389   10.00       21.60   22.40   21.40 Niskin bottle No problem reported    
367390   10.00        4.60    5.70    4.70 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.

Related Data Activity activities are detailed in Appendix 1

Cruise

Cruise Name CH118C
Departure Date 1995-04-27
Arrival Date 1995-05-12
Principal Scientist(s)Peter G Watson (Plymouth Marine Laboratory)
Ship RRS Challenger

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

Appendix 1: CH118C_CTD_CTD1

Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.

Series IdentifierData CategoryStart date/timeStart positionCruise
2248524Water sample data1995-04-28 07:55:0055.15676 N, 1.42518 WRRS Challenger CH118C