Metadata Report for BODC Series Reference Number 1303987
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.
D230 Discrete CTD Inorganic Nutrient Sampling Document
Originator's Protocol for Data Acquisition and Analysis
Sample collection and analysis
Discrete dissolved inorganic nutrient samples were collected from Niskin bottles fired on 141 CTD casts performed during D230. Samples were collected in 30 ml plastic diluvial sample cups, each washed three times in the sample flow. Samples were stored in a fridge (up to a maximum of four hours duration) prior to onboard analysis. 8 ml subsamples were drawn into sample cups and run on the SOC Chemlab AAII-type Auto-Analyser connected to a digital-analysis microstream data capture and reduction system. Duplicates were analysed to ensure accuracy and to increase precision.
Primary standards were prepared in calibrated 500 ml glass volumetric flasks (calibrated polyethylene volumetric flasks for silicate), one standard solution for each nutrient being required for the cruise. These utilised pre-weighed salts measured prior to the cruise. Sets of working standards were typically made up from these on a daily basis in 100 ml calibrated polyethylene volumetric flasks, using artificial seawater (40 g/l NaCl). These were run in duplicate prior to each analytical run to enable sample calibration. Independent quality control samples were also prepared from standard solutions supplied by OSI and run (in duplicate) at intervals throughout the analysis.
The cruise report contains more in depth details of each nutrient analysis performed during the cruise.
BODC Data Processing Procedures
ASCII-formatted CTD sample data from this cruise were supplied to BODC during March 2001. The inorganic nutrient data were extracted from these files and loaded into BODC's Oracle database. Flags were assigned if values were considered suspect.
Content of data series
|Originator's Parameter||Unit||Description||BODC Parameter code||BODC Unit||Comments|
|SiO3||µmol/l||Concentration of silicate per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis||SLCAAATX||µmol/l||No unit conversion necessary|
|NO2+NO3||µmol/l||NTRZAATX||µmol/l||No unit conversion necessary|
|PO4||µmol/l||Concentration of phosphate per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis||PHOSAATX||µmol/l||No unit conversion necessary|
Bacon, S., (1998). RRS Discovery Cruise 230, 07 AUG - 17 SEP 1997. FOUREX. Cruise Report No. 16 Southampton Oceanography Centre.
The UK made a substantial contribution to the international World Ocean Circulation Experiment (WOCE) project by focusing on two important regions:
- Southern Ocean - links all the worlds oceans, controlling global climate.
- North Atlantic - directly affects the climate of Europe.
A major part of the UK effort was in the Southern Ocean and work included:
- Two surveys, in the South Atlantic as part of the WOCE Hydrographic Programme.
- SWINDEX, a year long study of the Antarctic Circumpolar Current (ACC) where it crosses major topography south of Africa.
- ADOX, a study of deep water flow from the Atlantic to the Indian Ocean.
- ACCLAIM, a study of the ACC by altimetry and island measurements.
In the North Atlantic the UK undertook:
- NATRE, a purposeful tracer experiment to look at cross isopycnic processes.
- CONVEX, a study of the deep ocean circulation and its changes.
- VIVALDI, a seven year programme of seasonally repeated surveys to study the upper ocean.
- Long-term observations of ocean climate in the North West Approaches.
Satellite ocean surface topography, temperature and wind data were merged with in situ observations and models to create a complete description of ocean circulation, eddy motion and the way the ocean is driven by the atmosphere.
The surveys were forerunners to the international Global Ocean Observing System (GOOS). GOOS was later established to monitor annual to decadal changes in ocean circulation and heat storage which are vital in the prediction of climate change.
|Start Date (yyyy-mm-dd)||1997-08-19|
|End Date (yyyy-mm-dd)||1997-08-19|
|Organization Undertaking Activity||Southampton Oceanography Centre (now National Oceanography Centre, Southampton)|
|Country of Organization||United Kingdom|
|Originator's Data Activity Identifier||DI230_CTD_A25CTD039|
|Platform Category||lowered unmanned submersible|
BODC Sample Metadata Report for DI230_CTD_A25CTD039
|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|
|113734||10.00||2751.60||2753.10||2711.60||Niskin bottle||No problem reported|
|113735||10.00||2731.20||2732.70||2691.60||Niskin bottle||No problem reported|
|113736||10.00||2135.20||2136.70||2107.10||Niskin bottle||No problem reported|
|113737||10.00||1822.30||1823.80||1799.60||Niskin bottle||No problem reported|
|113738||10.00||1625.90||1627.40||1606.30||Niskin bottle||No problem reported|
|113739||10.00||1418.50||1420.00||1402.10||Niskin bottle||No problem reported|
|113740||10.00||1214.80||1216.30||1201.30||Niskin bottle||No problem reported|
|113741||10.00||1116.40||1117.90||1104.20||Niskin bottle||No problem reported|
|113742||10.00||1014.80||1016.30||1003.90||Niskin bottle||No problem reported|
|113743||10.00||931.30||932.80||921.40||Niskin bottle||No problem reported|
|113744||10.00||816.70||818.20||808.20||Niskin bottle||No problem reported|
|113745||10.00||714.10||715.60||706.80||Niskin bottle||No problem reported|
|113746||10.00||613.40||614.90||607.20||Niskin bottle||No problem reported|
|113747||10.00||519.90||521.40||514.70||Niskin bottle||No problem reported|
|113748||10.00||418.80||420.30||414.70||Niskin bottle||No problem reported|
|113749||10.00||320.00||321.50||316.80||Niskin bottle||No problem reported|
|113750||10.00||221.00||222.50||218.70||Niskin bottle||No problem reported|
|113751||10.00||171.00||172.50||169.20||Niskin bottle||No problem reported|
|113752||10.00||120.60||122.10||119.20||Niskin bottle||No problem reported|
|113753||10.00||65.60||67.10||64.70||Niskin bottle||No problem reported|
|113754||10.00||37.80||39.30||37.10||Niskin bottle||No problem reported|
|113755||10.00||12.90||14.40||12.40||Niskin bottle||No problem reported|
|113756||10.00||1.50||3.00||1.10||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.
|Principal Scientist(s)||Sheldon Bacon (Southampton Oceanography Centre)|
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|