Metadata Report for BODC Series Reference Number 1304954

Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Peter Saunders
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) UK WOCE

Data Identifiers

Originator's Identifier DI230_CTD_NUTS_129:A25CTD132
BODC Series Reference 1304954

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1997-09-12 22:47
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 57.69563 N ( 57° 41.7' N )
Longitude 13.94815 W ( 13° 56.9' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 5.3 m
Maximum Sensor Depth 130.2 m
Minimum Sensor Height 26.2 m
Maximum Sensor Height 151.1 m
Sea Floor Depth 156.4 m
Sensor Distribution Unspecified -
Sensor Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -


BODC CODE Rank Units Short Title Title
ADEPZZ01 1 Metres DepBelowSurf Depth below surface of the water body
BOTTFLAG 1 Dimensionless C22_flag Sampling process quality flag (BODC C22)
NTRZAATX 1 Micromoles per litre NO3+NO2_Unfilt_ColAA Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
PHOSAATX 1 Micromoles per litre PO4_Unfilt_ColAA Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SAMPRFNM 1 Dimensionless SampRef Sample reference number
SLCAAATX 1 Micromoles per litre SiOx_Unfilt_ColAA Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis

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 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."

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.


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
SiO 3 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
NO 2 +NO 3 µmol/l Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRZAATX µmol/l No unit conversion necessary
PO 4 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.

Project Information


The UK made a substantial contribution to the international World Ocean Circulation Experiment (WOCE) project by focusing on two important regions:

  1. Southern Ocean - links all the worlds oceans, controlling global climate.
  2. North Atlantic - directly affects the climate of Europe.

A major part of the UK effort was in the Southern Ocean and work included:

In the North Atlantic the UK undertook:

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.

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1997-09-12
End Date (yyyy-mm-dd) 1997-09-12
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierDI230_CTD_A25CTD132
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for DI230_CTD_A25CTD132

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
115561   10.00      131.90  133.40  130.20 Niskin bottle No problem reported    
115562   10.00      102.60  104.10  101.20 Niskin bottle No problem reported    
115563   10.00       52.70   54.20   51.80 Niskin bottle No problem reported    
115564   10.00       27.40   28.90   26.70 Niskin bottle No problem reported    
115565   10.00       10.80   12.30   10.30 Niskin bottle No problem reported    
115566   10.00        5.70    7.20    5.30 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 Name D230
Departure Date 1997-08-07
Arrival Date 1997-09-17
Principal Scientist(s)Sheldon Bacon (Southampton Oceanography Centre)
Ship RRS Discovery

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

Station NameExtended Ellett Line
CategoryOffshore route/traverse

Extended Ellett Line

The Extended Ellett Line is a hydrographic transect consisting of 64 individual fixed stations which have been occupied, typically on an annual basis, since September 1996. The Line runs from the south of Iceland, across the Iceland Basin to the outcrop of Rockall, and across the Rockall Trough to the north west coast of Scotland (see map). CTD dips and associated water sampling for the analysis of nutrients are routinely performed during each station occupation.

The Extended Ellett Line augments the original Ellett Line time series - a shorter repeated transect which encompassed those stations between Rockall and Scotland. Work on the Ellett Line was typically carried out at least once a year between 1975 and 1996.

Map of standard stations (1996-present)

BODC image

Map produced using the GEBCO Digital Atlas

The white triangles indicate the nominal positions of the Extended Ellett Line stations visited since September 1996. Measurements made along the Extended Ellett Line lie within a box bounded by co-ordinates 56° N, 21° W at the south west corner and 65° N, 6° W at the north east corner.

Nominal Extended Ellett Line stations (September 1996-present)

Listed below are nominal details of the standard hydrographic stations that form the Extended Ellett Line. The majority of these stations have been sampled since the outset, although several have been added more recently.

Station Latitude Longitude Depth Range
IB23S 63.318 N 20.210 W 125 m -
IB22S 63.217 N 20.067 W 660 m 0.0 nm
IB21S 63.133 N 19.917 W 1030 m 6.5 nm
IB20S 62.917 N 19.550 W 1415 m 16.4 nm
IB19S 62.667 N 19.667 W 1500 m 16.0 nm
IB18S 62.333 N 19.833 W 1800 m 16.0 nm
IB17 62.000 N 20.000 W 1700 m 20.6 nm
IB16A 61.750 N 20.000 W 1797 m -
IB16 61.500 N 20.000 W 2000 m 30.1 nm
IB15 61.250 N 20.000 W 2375 m 15.0 nm
IB14 61.000 N 20.000 W 2400 m 15.0 nm
IB13A 60.750 N 20.000 W 2500 m -
IB13 60.500 N 20.000 W 2500 m 30.1 nm
IB12A 60.250 N 20.000 W 2600 m -
IB12 60.000 N 20.000 W 2700 m 30.1 nm
IB11A 59.833 N 19.500 W 2700 m -
IB11 59.667 N 19.117 W 2680 m 33.3 nm
IB10 59.400 N 18.417 W 2420 m 26.7 nm
IB9 59.333 N 18.233 W 1910 m 6.9 nm
IB8 59.200 N 17.883 W 1540 m 13.4 nm
IB7 59.117 N 17.667 W 1000 m 8.3 nm
IB6 58.950 N 17.183 W 850 m 18.0 nm
IB5 58.883 N 17.000 W 1150 m 7.0 nm
IB4A 58.667 N 16.500 W 1170 m -
IB4 58.500 N 16.000 W 1210 m 38.8 nm
IB3 58.250 N 15.333 W 680 m 25.8 nm
IB2 57.950 N 14.583 W 480 m 29.9 nm
IB1 57.667 N 13.900 W 160 m 27.7 nm
A 57.583 N 13.633 W 130 m 10.0 nm
B 57.567 N 13.333 W 210 m 9.7 nm
C 57.550 N 13.000 W 330 m 10.8 nm
D 57.542 N 12.867 W 1000 m 4.3 nm
E 57.533 N 12.633 W 1658 m 7.6 nm
F 57.508 N 12.250 W 1817 m 12.5 nm
G 57.492 N 11.850 W 1812 m 13.0 nm
H 57.483 N 11.533 W 2020 m 10.3 nm
I 57.467 N 11.317 W 750 m 7.0 nm
J 57.450 N 11.083 W 550 m 7.6 nm
K 57.400 N 10.867 W 850 m 7.6 nm
L 57.367 N 10.667 W 2076 m 6.8 nm
M 57.300 N 10.383 W 2340 m 10.1 nm
N 57.233 N 10.050 W 2100 m 11.5 nm
O 57.150 N 9.700 W 1900 m 12.4 nm
P 57.100 N 9.417 W 1050 m 9.7 nm
Q 57.050 N 9.217 W 350 m 7.2 nm
Q1 57.075 N 9.317 W 800 m -
R 57.000 N 9.000 W 135 m 7.7 nm
S 56.950 N 8.783 W 125 m 7.7 nm
15G 56.883 N 8.500 W 125 m 10.1 nm
T 56.837 N 8.333 W 120 m 6.1 nm
14G 56.808 N 8.167 W 115 m 5.7 nm
13G 56.783 N 8.000 W 110 m 5.7 nm
12G 56.758 N 7.833 W 80 m 5.7 nm
11G 56.733 N 7.667 W 55 m 5.7 nm
10G 56.733 N 7.500 W 220 m 5.5 nm
9G 56.733 N 7.333 W 160 m 5.5 nm
8G 56.733 N 7.167 W 175 m 5.5 nm
7G 56.733 N 7.000 W 145 m 5.5 nm
6G 56.733 N 6.750 W 35 m 8.2 nm
5G 56.733 N 6.600 W 75 m 4.9 nm
4G 56.733 N 6.450 W 115 m 4.9 nm
3G 56.708 N 6.367 W 75 m 3.1 nm
2G 56.683 N 6.283 W 40 m 3.2 nm
1G 56.667 N 6.133 W 190 m 5.0 nm

Occupations of the Extended Ellett Line (September 1996-present)

BODC Cruise Identifier Cruise Dates Ship
D223A 28 September-21 October 1996 RRS Discovery
D230 7 August-17 September 1997 RRS Discovery
D233 23 April-1 June 1998 RRS Discovery
D242 7 September-6 October 1999 RRS Discovery
D245 * 27 January-20 February 2000 RRS Discovery
0700S * 8-22 May 2000 FRV Scotia
D253 4 May-20 June 2001 RRS Discovery
0703S * 15 April-5 May 2003 FRV Scotia
PO300_2 * 19 July-6 August 2003 RRS Poseidon
PO314 11 July-23 July 2004 RV Poseidon
CD176 6 October-1 November 2005 RRS Charles Darwin
D312 11-31 October 2006 RRS Discovery
D321A 24 July-23 August 2007 RRS Discovery
D321B 24 August-9 September 2007 RRS Discovery
0508S * 6-25 May 2008 FRV Scotia
D340A 10-25 June 2009 RRS Discovery
D351 10-28 May 2010 RRS Discovery
D365 13 May-02 June 2011 RRS Discovery
D379 31 July-17 August 2012 RRS Discovery
JC086 6-26 May 2013 RRS James Cook
JR302 6 June-22 July 2014 RRS James Clark Ross
DY031 29 May- 17 June 2015 RRS Discovery
DY052 7-24 June 2016 RRS Discovery

* These cruises only surveyed the original hydrographic section between Scotland and Rockall.

Other Series linked to this Fixed Station for this cruise - 1007936 1007948 1007961 1007973 1007985 1007997 1008000 1008012 1008024 1008036 1008048 1008061 1008073 1008085 1008097 1008269 1008270 1008282 1008294 1008301 1008313 1008325 1008337 1008349 1008350 1008362 1008374 1008386 1008398 1008405 1008417 1008429 1008430 1304745 1304757 1304769 1304770 1304782 1304794 1304801 1304813 1304825 1304837 1304849 1304850 1304862 1304874 1304886 1304898 1304905 1304917 1304929 1304930 1304942 1304966 1304978 1304991 1305005 1305017 1305029 1305030 1305042 1305054 1305066

Other Cruises linked to this Fixed Station (with the number of series) - 0508S (58) 0700S (30) 0703S (20) CD176 (40) D223A (22) D233 (49) D242 (89) D245 (25) D253 (41) D312 (51) D321 (D321A) (7) D321B (41) D340A (58) D351 (23) D365 (55) D379 (64) DY052 (144) JC086 (59) JR20140531 (JR302) (75) PO300_2 (31) PO314 (53)

Fixed Station Information

Station NameExtended Ellett Line Station IB1
CategoryOffshore location
Latitude57° 40.02' N
Longitude13° 54.00' W
Water depth below MSL160.0 m

Extended Ellett Line: Fixed Station IB1

Station IB1 is one of the fixed CTD stations, which together form The Extended Ellett Line. The line lies between Iceland and the Sound of Mull (Scotland) crossing the Iceland Basin and Rockall Trough via the outcrop of Rockall. As part of this initiative, CTD dips, together with associated discrete sampling of the water column, have typically been carried out annually at this station since September 1996.

Other Series linked to this Fixed Station for this cruise - 1007973

Other Cruises linked to this Fixed Station (with the number of series) - D242 (2) D312 (1) D321B (1) D340A (1) D351 (1) D379 (1) DY031 (2) DY052 (2) JC086 (1) JR20140531 (JR302) (1) PO314 (1)

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