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Metadata Report for BODC Series Reference Number 2055266


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
Digitron 2000 series 2028T Thermometer  water temperature sensor
PerkinElmer Model LAMBDA series 35 spectrophotometer  spectrophotometers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Vassilis Kitidis
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Oceans 2025 Theme 10 SO1:AMT
 

Data Identifiers

Originator's Identifier D371_CTD_CO2X_2045:CTD061
BODC Series Reference 2055266
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2011-10-31 05:34
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 28.70050 S ( 28° 42.0' S )
Longitude 25.94911 W ( 25° 56.9' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 4.2 m
Maximum Sensor or Sampling Depth 1000.6 m
Minimum Sensor or Sampling Height 4237.1 m
Maximum Sensor or Sampling Height 5233.5 m
Sea Floor Depth 5237.7 m
Sea Floor Depth Source PEVENT
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
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)
FIRSEQID1DimensionlessBottle firing sequence number
PHMASSXX1pH unitspH (total scale) {pH[T]} of the water body
PHTLWCAL1pH unitspH (total scale) {pH[T]} of the water body by computation
PHTXPR011Degrees CelsiusTemperature of pH determination
ROSPOSID1DimensionlessBottle rosette position identifier
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

Digitron 2000 series 2028T Thermometer

Digitron 2000 series are a range of hand-held digital thermometers. The 2028T model presents readings in seconds with an accuracy of 0.2%. Digitron provide a unique SpeedRead feature which supplies an answer in 14 seconds or if this measurement cannot be made the instrument automatically reverts back to a standard thermometer accuracy. Additional features of the Digitron 2000 series include logging mode for storage, retrieval and output of readings and a long battery life of approximately 500 hours. The 2028T thermometer provides Celsius or Fahrenheit function and has a temperature range of 200°C to +1350°C/ -328°F to +2462°F.

Common specifications of the instrument can be found in the table below:

Resolution: 0.1° from -199.9°C to +199.9°C/-199.9°F to +392.0°F 1°C elsewhere
Operating Temperature: -10°C to +50°C/+14°F to +122°F (ambient)
Battery Type: Two AA or equivalent cells (not supplied)
Battery Life: Typically 500 hours
Low Battery Check: symbol appears on display
Display: 12.7mm / 0.5" custom L.C.D.
Sensor Open Circuit: Indicated by 'O-C' on display
Over range/Under range: 'Out' displayed
Cold Junction Compensation: Yes
Environmental Specifications: IP65 (IP67 optional)
Auto Switch-Off Time: 12 minutes
Dimensions: 155 x 67 x 40mm/6.1 x 2.6 x 1.6"
Weight: 180g/6.4oz
Instrument Accuracy: 0.1% rdg ±0.2°C/0.4°F above -100°C/-148°F
  0.5% rdg ±0.2°C/0.4°F below -100°C/-148°F

Further information can be found in the manufacturers manual.

Additional information can also be found on the technical data sheet.

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.

Carbonate chemistry - pH from CTD bottles during AMT21(D371)

Originator's Protocol for Data Acquisition and Analysis

As part of the Atlantic Meridional Transect (AMT) (AMT 21) a total of 74 CTD casts were obtained onboard the D371 cruise. This annual return passage from the UK to the Falkland Islands took place from September to November 2011.

Samples were obtained from each of the 74 CTD positions. CTD casts were recorded using the Sea-Bird data collection software Seasave-Win32. The software outputs were then processed following the BODC recommended guidelines using SBE Data ProcessingWin32 v7.20g

pH samples (total scale) were collected from the CTD hydrocast using 250 mL amber glass bottles. pH was determined using a Perkin-Elmer Lambda 35 spectrophotometer which measured the absorbance at 434, 578 and 730 nm with a 10 cm quartz cuvette. The samples were initially placed in a water bath at 25°C to achieve temperature equilibration. A 2 mmol/L solution of m-cresol purple (Sigma-Alrich, product number: 857890-5G) was prepared for spectrophotometric pH determination, with 100 µL of this dye solution added directly to the cuvette. Absorbance, before and after the addition of the dye solution, was measured. A pH correction for the dye supplement was applied using the method in Dickson et al. (2007).

In-situ pH (total scale) was calculated using CO2SYS software following a protocol obtained from Dickson et al. (2007). Temperature within the spectrophotometer, which was measured throughout the analysis, was recorded using a Digitron 2028T thermometer.

References Cited

Dickson, A.G., Sabine, C.L., Christion, J.R., 2007. Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, PICES Special Publication 3, p. 191.

D371 Cruise report

Further information can be found in the D371 Cruise report.

BODC Data Processing Procedures

The data arrived at BODC in excel format representing data collected from the 74 CTD stations. The data were loaded into the BODC database using established BODC data banking procedures. Supplied replicate samples were averaged and the standard deviation calculated before loading into the database. The data were mapped to BODC parameter codes.

Originator's Variable Originator's Units BODC Parameter Code BODC Unit Comments
pH in situ - PHTLWCAL pH units null
- - PHTLSDWC pH units Created when BODC averaged replicates
pH meas - PHMASSXX pH units null
- - PHMASSSD pH units Created when BODC averaged replicates
T meas degrees PHTXPR01 degC null
- - PHTXSD01 degC Created when BODC averaged replicates

Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 1: The Atlantic Meridional Transect (AMT)

The Atlantic Meridional Transect has been operational since 1995 and through the Oceans 2025 programme secures funding for a further five cruises during the period 2007-2012. The AMT programme began in 1995 utilising the passage of the RRS James Clark Ross between the UK and the Falkland Islands southwards in September and northwards in April each year. Prior to Oceans 2025 the AMT programme has completed 18 cruises following this transect in the Atlantic Ocean. This sustained observing system aims to provide basin-scale understanding of the distribution of planktonic communities, their nutrient turnover and biogenic export in the context of hydrographic and biogeochemical provinces of the North and South Atlantic Oceans.

The Atlantic Meridional Transect Programme is an open ocean in situ observing system that will:

  • give early warning of any fundamental change in Atlantic ecosystem functionng
  • improve forecasts of the future ocean state and associated socio-economic impacts
  • provide a "contextual" logistical and scientific infrastructure for independently-funded national and international open ocean biogeochemical and ecological research.

The specific objectives are:

  • To collect hydrographic, chemical, ecological and optical data on transects between the UK and the Falkland Islands
  • To quantify the nature and causes of ecological and biogeochemical variability in planktonic ecosystems
  • To assess the effects of variability in planktonic ecosystems on biogenic export and on air-sea exchange of radiatively active gases

The measurements taken and experiments carried out on the AMT cruises will be closely linked to Themes 2 and 5. The planned cruise track also allows for the AMT data to be used in providing spatial context to the Sustained Observation Activities at the Porcupine Abyssal Plain Ocean Observatory (SO2) and the Western Channel Observatory (SO10).

More detailed information on this Work Package is available at pages 6 - 9 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10

Weblink: http://www.oceans2025.org/


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2011-10-31
End Date (yyyy-mm-dd) 2011-10-31
Organization Undertaking ActivityPlymouth Marine Laboratory
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierD371_CTD_CTD061
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for D371_CTD_CTD061

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
621206   20.00 1 1 1009.50 1011.60 1000.60 Niskin bottle No problem reported    
621209   20.00 2 2  304.20  306.00  302.10 Niskin bottle No problem reported    
621212   20.00 3 3  204.00  205.20  202.40 Niskin bottle No problem reported    
621215   20.00 4 4  173.10  175.40  172.30 Niskin bottle No problem reported    
621218   20.00 5 5  144.00  144.80  142.70 Niskin bottle No problem reported    
621221   20.00 6 6  123.70  124.60  122.60 Niskin bottle No problem reported    
621224   20.00 7 7  106.50  109.30  106.40 Niskin bottle No problem reported    
621227   20.00 8 8  107.60  108.20  106.40 Niskin bottle No problem reported    
621230   20.00 9 9  107.00  108.60  106.30 Niskin bottle No problem reported    
621233   20.00 10 10  107.00  108.60  106.30 Niskin bottle No problem reported    
621236   20.00 11 11   93.80   95.60   93.30 Niskin bottle No problem reported    
621239   20.00 12 12   81.30   81.90   80.30 Niskin bottle No problem reported    
621242   20.00 13 13   68.40   68.90   67.50 Niskin bottle No problem reported    
621245   20.00 14 14   67.70   69.70   67.50 Niskin bottle No problem reported    
621248   20.00 15 15   50.80   52.10   50.40 Niskin bottle No problem reported    
621251   20.00 16 16   50.60   51.90   50.20 Niskin bottle No problem reported    
621254   20.00 17 17   29.90   30.40   29.20 Niskin bottle No problem reported    
621257   20.00 18 18   29.70   30.30   29.10 Niskin bottle No problem reported    
621260   20.00 19 19   22.40   23.70   22.20 Niskin bottle No problem reported    
621263   20.00 20 20   17.60   18.60   17.30 Niskin bottle No problem reported    
621266   20.00 21 21   17.80   18.30   17.20 Niskin bottle No problem reported    
621269   20.00 22 22    4.20    5.20    4.00 Niskin bottle No problem reported    
621272   20.00 23 23    4.30    5.60    4.20 Niskin bottle No problem reported    
621275   20.00 24 24    4.00    5.50    4.00 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.

Related Data Activity activities are detailed in Appendix 1

Cruise

Cruise Name D371 (AMT21)
Departure Date 2011-09-29
Arrival Date 2011-11-13
Principal Scientist(s)Glen A Tarran (Plymouth Marine Laboratory)
Ship RRS Discovery

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: D371_CTD_CTD061

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
1341031Water sample data2011-10-31 05:34:0028.7005 S, 25.94911 WRRS Discovery D371 (AMT21)
2006457Water sample data2011-10-31 05:34:0028.7005 S, 25.94911 WRRS Discovery D371 (AMT21)
2123007Water sample data2011-10-31 05:34:0028.7005 S, 25.94911 WRRS Discovery D371 (AMT21)
2126619Water sample data2011-10-31 05:34:0028.7005 S, 25.94911 WRRS Discovery D371 (AMT21)