Metadata Report for BODC Series Reference Number 1666771
Definition of BOTTFLAG
|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
No Problem Report Found in the Database
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
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.
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.
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.
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.
Pigments for Charles Darwin and RRS Challenger cruises
Converted from CDROM documentation.
Content of data series
|Fluorometric assay of acetone extract (GF/F filtered)|
|Fluorometric assay of acetone extraction (sum of size fractions >0.2 microns)|
|Calibrated in-situ fluorometer|
|Fluorometric assay of acetone extract (GF/F filtered)|
|SCHLFLPF||Size-fractionated fluorometric chlorophyll-a|
|Fluorometric assay of an acetone extract (0.2-2µm size fraction)|
|SCHLFLPG||Size-fractionated fluorometric chlorophyll-a|
|Fluorometric assay of an acetone extract (2-20µm size fraction)|
|SCHLFLPQ||Size-fractionated fluorometric chlorophyll-a|
|Fluorometric assay of an acetone extract (>20µm size fraction)|
Dr Ken Jones, CCMS Dunstaffnage Marine Laboratory, UK.
Sampling strategy and methodology
Charles Darwin cruises CD91B, CD93A and CD93B and RRS Challenger cruises CH121A, CH121B, CH121C, CH123A, CH123B, CH125A, CH125B, CH126A, CH126B, CH128A and CH128B.
Samples were collected from either the non-toxic surface sea water supply or from Niskin bottles fitted to the CTD rosette. They were taken in Nalgene bottles, rinsed twice with sample water prior to filling.
The samples were vacuum filtered through 2.5 cm GF/F filters. The volume of water filtered varied depending on the particulate load in the sample. The filters were folded and immediately frozen.
Back in the laboratory, the filters were extracted into 8 ml of 90% neutralised acetone and stored for between 18 and 36 hours in a refrigerator. The extracts were centrifuged at 3000 rpm for two 5-minute bursts.
The resulting chlorophyll solutions were assayed on a bench fluorometer. Three drops of 8% HCl were added and the assay was repeated. Chlorophyll-a and phaeopigment concentrations were determined from the two fluorometer readings using the equations in Tett and Grantham (1978).
Tett P. and Grantham B. 1978. A simple guide to the measurement and interpretation of chlorophyll concentration, temperature and salinity, in coastal waters. SMBA. 85pp.
LOIS Shelf Edge Study (LOIS - SES)
SES was a component of the NERC Land Ocean Interaction Study (LOIS) Community Research Programme that made intensive measurements from the shelf break in the region known as the Hebridean Slope from March 1995 to September 1996.
SES was devoted to the study of interactions between the shelf seas and the open ocean. The specific objectives of the project were:
To identify the time and space scales of ocean-shelf momentum transmission and to quantify the contributions to ocean-shelf water exchange by physical processes.
To estimate fluxes of water, heat and certain dissolved and suspended constituents across a section of the shelf edge with special emphasis on net carbon export from, and nutrient import to, the shelf.
To incorporate process understanding into models and test these models by comparison with observations and provide a basis for estimation of fluxes integrated over time and the length of the shelf.
The SES fieldwork was focussed on a box enclosing two sections across the shelf break at 56.4-56.5 °N and 56.6-56.7 °N. Moored instrument arrays were maintained throughout the experiment at stations with water depths ranging from 140 m to 1500 m, although there were heavy losses due to the intensive fishing activity in the area. The moorings included meteorological buoys, current meters, transmissometers, fluorometers, nutrient analysers (but these never returned any usable data), thermistor chains, colour sensors and sediment traps.
The moorings were serviced by research cruises at approximately three-monthly intervals. In addition to the mooring work this cruises undertook intensive CTD, water bottle and benthic surveys with cruise durations of up to 6 weeks (3 legs of approximately 2 weeks each).
Moored instrument activities associated with SES comprised current measurements in the North Channel in 1993 and the Tiree Passage from 1995-1996. These provided boundary conditions for SES modelling activities.
Additional data were provided through cruises undertaken by the Defence Evaluation and Research Agency (DERA) in a co-operative programme known as SESAME.
|Start Date (yyyy-mm-dd)||1996-07-16|
|End Date (yyyy-mm-dd)||1996-07-16|
|Organization Undertaking Activity||University of Wales, Bangor School of Ocean Sciences (now Bangor University School of Ocean Sciences)|
|Country of Organization||United Kingdom|
|Originator's Data Activity Identifier||CH128A_CTD_CP29|
|Platform Category||lowered unmanned submersible|
BODC Sample Metadata Report for CH128A_CTD_CP29
|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|
|83975||10.00||139.80||140.50||137.50||Niskin bottle||No problem reported|
|83976||10.00||34.60||36.40||33.90||Niskin bottle||No problem reported|
|83977||10.00||5.10||5.60||4.00||Niskin bottle||No problem reported|
|84396||10.00||104.60||104.90||102.50||Niskin bottle||No problem reported|
|84397||10.00||64.40||65.00||62.80||Niskin bottle||No problem reported|
|84398||10.00||16.80||17.60||15.70||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
|Principal Scientist(s)||John H Simpson (University of Wales, Bangor School of Ocean Sciences)|
Complete Cruise Metadata Report is available here
No Fixed Station Information held for the Series
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
|<||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.)|
|E||End of CTD Down/Up Cast|
|G||Non-taxonomic biological characteristic uncertainty|
|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|
|O||Improbable value - user quality control|
|0||no quality control|
|2||probably good value|
|3||probably bad value|
|6||value below detection|
|7||value in excess|
|A||value phenomenon uncertain|
|Q||value below limit of quantification|
Appendix 1: CH128A_CTD_CP29
Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.
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|Series Identifier||Data Category||Start date/time||Start position||Cruise|
|1292214||Water sample data||1996-07-16 13:36:00||56.45334 N, 8.18572 W||RRS Challenger CH128A|