Metadata Report for BODC Series Reference Number 670458


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Neil Brown MK3 CTD  CTD; water temperature sensor; salinity sensor; dissolved gas sensors
Chelsea Technologies Group Alphatracka transmissometer  transmissometers
National Marine Facilities Microelectrode Oxygen Sensor  dissolved gas sensors
Chelsea Technologies Group Aquatracka III fluorometer  fluorometers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Ms Jane Read
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) -
 

Data Identifiers

Originator's Identifier CTD13966
BODC Series Reference 670458
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2001-05-07 11:35
End Time (yyyy-mm-dd hh:mm) 2001-05-07 11:41
Nominal Cycle Interval 2.0 decibars
 

Spatial Co-ordinates

Latitude 57.54417 N ( 57° 32.7' N )
Longitude 13.94817 W ( 13° 56.9' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 0.99 m
Maximum Sensor Depth 133.71 m
Minimum Sensor Height 9.35 m
Maximum Sensor Height 142.07 m
Sea Floor Depth 143.07 m
Sensor Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
CNDCST01 1 Siemens per metre CTDCond Electrical conductivity of the water body by CTD
CPHLPR01 1 Milligrams per cubic metre chl-a_water_ISfluor Concentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >unknown phase] by in-situ chlorophyll fluorometer
DOXYZZ01 1 Micromoles per litre WC_dissO2_IS Concentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ sensor
OXYSSC01 1 Percent BK_SBE43 Saturation of oxygen {O2 CAS 7782-44-7} in the water body [dissolved plus reactive particulate phase] by Sea-Bird SBE 43 sensor and calibration against sample data and computation from concentration using Benson and Krause algorithm
POPTDR01 1 Percent Trans_Red_25cm Transmittance (red light wavelength) per 25cm of the water body by 25cm path length red light transmissometer
POTMCV01 1 Degrees Celsius WC_Potemp Potential temperature of the water body by computation using UNESCO 1983 algorithm
PRESPR01 1 Decibars Pres_Z Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level
PSALST01 1 Dimensionless P_sal_CTD Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm
SIGTPR01 1 Kilograms per cubic metre SigTheta Sigma-theta of the water body by CTD and computation from salinity and potential temperature using UNESCO algorithm
TEMPST01 1 Degrees Celsius WC_temp_CTD Temperature of the water body by CTD or STD
 

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

Quality report - D253 Pascal Oxygen sensor data

From visualising the data it is clear that the Pascal Oxygen sensor did not perform well during this cruise. This channel was not calibrated against bottle samples and from the values they appear either far too low or far too high. Therefore all the data from this Oxygen sensor have been flagged 'M' by BODC and consequently the derived Oxygen saturation channel has been flagged too.

CTD casts that included a Pascal Oxygen sensor -


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

National Marine Facilities Microelectrode Oxygen Sensor

The Microelectrode Oxygen Sensor is a non-membrane dissolved oxygen sensor developed by the Ocean Engineering Division of National Marine Facilities (NMF) at the National Oceanography Centre, and the Electro-Chemistry Group at the University of Southampton Chemistry Department. The sensor is suitable for marine applications. It was first used in 2000 and development is ongoing.

The fundamental parts of the sensor are a platinum microelectrode and a counter electrode (thus far composed of copper). A measurement potential is applied to the microelectrode relative to the counter electrode. This leads to reduction of dissolved oxygen at the microelectrode and produces a current proportional to the number of oxygen molecules at that electrode.

The sensor is suitable for operation on a CTD system as it is free from the pressure effects (e.g. slow response, drift and hysteresis) typically encountered when using oxygen sensors that employ a membrane. Its short response time (approximately 1 second) also makes it suitable for deployment on CTDs and oceanographic undulators. The sensor includes both analogue voltage and serial digital (RS 232) outputs.

The electrode surface is reconditioned by applying a cleaning potential to the microelectrode at which oxidation occurs. This minimises drift and the effects of bio-fouling.

Ongoing development

Early versions of the instrument applied the measurement potential for up to 30 seconds, with sampling starting approximately one second after the potential was applied. The sensor response to oxygen remained almost constant for a given concentration and data could be sampled at frequencies exceeding 1 Hz.

However, the sensor proved to be very sensitive to fluctuations in flow, leading to apparent noise in the data. In an attempt to address this, various changes were made to the functionality:

Instrument Description

CTD Unit and Auxiliary Sensors

During this cruise, two separate CTD rigs with different sensors were deployed for different sections of the line.
CTD stations 13965 to 14026 used the Neil Brown Mk3 CTD and are called subaccession A
CTD stations 14027 to 14062 used the Sea-Bird 911 CTD are called subaccession B
CTD stations 14064 to 14130 used the Neil Brown Mk3 CTD and are called subaccession A

Sensor Serial Number Last calibration date Comments
Neil Brown Mk3 CTD unit with FSI rosette pylon 24 bottle IM960513 December 1999 Used for subaccession A deployments
Sea_Bird 911 CTD unit 09P24680-0636 No information Used for subaccession B deployments
Pylon: Sea-Bird 32 Carousel/24-bottle position 32-24680-0345 No information Used for subaccession B deployments
Chelsea Instruments Aquatracka 61/2642/003 No information Used for subaccession A deployments
Chelsea MKII Alphatracka 25cm path Transmissometer 161047 No information Used for subaccession B deployments
Chelsea MKIII Aquatracka Fluorimeter 88-2360-108 No information Used on both A and B deployments
Pascal Oxygen Sensor No information No information Used for subaccession A deployments
Sea-Bird SBE 43B dissolved oxygen sensor 43B-0008 No information Used for subaccession B deployments
Primary Premium Temperature Sensor 3P 03P-4107 No information Used for subaccession B deployments
Primary Conductivity Sensor 4C 04C-2573 No information Used for subaccession B deployments
Digiquartz Temperature Compensated Pressure Sensor 83008 No information Used for subaccession B deployments

Neil Brown MK3 CTD

The Neil Brown MK3 conductivity-temperature-depth (CTD) profiler consists of an integral unit containing pressure, temperature and conductivity sensors with an optional dissolved oxygen sensor in a pressure-hardened casing. The most widely used variant in the 1980s and 1990s was the MK3B. An upgrade to this, the MK3C, was developed to meet the requirements of the WOCE project.

The MK3C includes a low hysteresis, titanium strain gauge pressure transducer. The transducer temperature is measured separately, allowing correction for the effects of temperature on pressure measurements. The MK3C conductivity cell features a free flow, internal field design that eliminates ducted pumping and is not affected by external metallic objects such as guard cages and external sensors.

Additional optional sensors include pH and a pressure-temperature fluorometer. The instrument is no longer in production, but is supported (repair and calibration) by General Oceanics.

Specifications

These specification apply to the MK3C version.

Pressure Temperature Conductivity
Range

6500 m

3200 m (optional)

-3 to 32°C 1 to 6.5 S cm -1
Accuracy

0.0015% FS

0.03% FS < 1 msec

0.0005°C

0.003°C < 30 msec

0.0001 S cm -1

0.0003 S cm -1 < 30 msec

Further details can be found in the specification sheet .

Chelsea Technologies Group Aquatracka MKIII fluorometer

The Chelsea Technologies Group Aquatracka MKIII is a logarithmic response fluorometer. Filters are available to enable the instrument to measure chlorophyll, rhodamine, fluorescein and turbidity.

It uses a pulsed (5.5 Hz) xenon light source discharging along two signal paths to eliminate variations in the flashlamp intensity. The reference path measures the intensity of the light source whilst the signal path measures the intensity of the light emitted from the specimen under test. The reference signal and the emitted light signals are then applied to a ratiometric circuit. In this circuit, the ratio of returned signal to reference signal is computed and scaled logarithmically to achieve a wide dynamic range. The logarithmic conversion accuracy is maintained at better than one percent of the reading over the full output range of the instrument.

Two variants of the instrument are available, both manufactured in titanium, capable of operating in depths from shallow water down to 2000 m and 6000 m respectively. The optical characteristics of the instrument in its different detection modes are visible below:

Excitation Chlorophyll a Rhodamine Fluorescein Turbidity
Wavelength (nm) 430 500 485 440 *
Bandwidth (nm) 105 70 22 80 *
Emission Chlorophyll a Rhodamine Fluorescein Turbidity
Wavelength (nm) 685 590 530 440 *
Bandwidth (nm) 30 45 30 80 *

* The wavelengths for the turbidity filters are customer selectable but must be in the range 400 to 700 nm. The same wavelength is used in the excitation path and the emission path.

The instrument measures chlorophyll a, rhodamine and fluorescein with a concentration range of 0.01 µg l -1 to 100 µg l -1 . The concentration range for turbidity is 0.01 to 100 FTU (other wavelengths are available on request).

The instrument accuracy is ± 0.02 µg l -1 (or ± 3% of the reading, whichever is greater) for chlorophyll a, rhodamine and fluorescein. The accuracy for turbidity, over a 0 - 10 FTU range, is ± 0.02 FTU (or ± 3% of the reading, whichever is greater).

Further details are available from the Aquatracka MKIII specification sheet .

Chelsea Technologies Group ALPHAtracka and ALPHAtracka II transmissometers

The Chelsea Technologies Group ALPHA tracka (the Mark I) and its successor, the ALPHA tracka II (the Mark II), are both accurate (< 0.3 % fullscale) transmissometers that measure the beam attenuation coefficient at 660 nm. Green (565 nm), yellow (590 nm) and blue (470 nm) wavelength variants are available on special order.

The instrument consists of a Transmitter/Reference Assembly and a Detector Assembly aligned and spaced apart by an open support frame. The housing and frame are both manufactured in titanium and are pressure rated to 6000 m depth.

The Transmitter/Reference housing is sealed by an end cap. Inside the housing an LED light source emits a collimated beam through a sealed window. The Detector housing is also sealed by an end cap. A signal photodiode is placed behind a sealed window to receive the collimated beam from the Transmitter.

The primary difference between the ALPHA tracka and ALPHA tracka II is that the Alphatracka II is implemented with surface-mount technology; this has enabled a much smaller diameter pressure housing to be used while retaining exactly the same optical train as in the Mark I. Data from the Mark II version are thus fully compatible with that already obtained with the Mark I. The performance of the Mark II is further enhanced by two electronic developments from Chelsea Technologies Group - firstly, all items are locked in a signal nulling loop of near infinite gain and, secondly, the signal output linearity is inherently defined by digital circuitry only.

Among other advantages noted above, these features ensure that the optical intensity of the Mark II, indicated by the output voltage, is accurately represented by a straight line interpolation between a reading near full-scale under known conditions and a zero reading when blanked off.

For optimum measurements in a wide range of environmental conditions, the Mark I and Mark II are available in 5 cm, 10 cm and 25 cm path length versions. Output is default factory set to 2.5 volts but can be adjusted to 5 volts on request.

Further details about the Mark II instrument are available from the Chelsea Technologies Group ALPHA tracka II specification sheet .

BODC Processing

The CTD data were supplied to BODC in 156 PStar files and converted to the BODC internal format, a netCDF subset.

During transfer the originator's variables were mapped to unique BODC parameter codes. The following table shows the parameter mapping. During the cruise, two separate CTD rigs were employed for different sections of the line:- a Neil Brown CTD and a Sea-Bird CTD, which in some cases had different sensors measuring the same quantity. CTD casts recorded by the Neil Brown CTD are identified as subaccession A, those recorded by the Sea-Bird CTD are subaccession B. Where the same originator's variable in the source files was recorded by different sensors on different CTD rigs (possibly resulting in a different BODC parameter mapping) this has been made clear in the table below.

Originator's variable Units Description BODC Code Units Comments
time - Time - - Not transferred - will be superseded in BODC processing
press db Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level. PRESPR01 db -
temp °C Temperature of the water body by CTD or STD TEMPST01 °C -
cond Subacc A: mmho/cm
Subacc B: mS/cm
Electrical conductivity of the water body by CTD CNDCST01 S/m cond divided by 10 for subacc A and B
salinity psu Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm PSALST01 Dimensionless -
fluor Subacc A: mg/m 3
Subacc B: volts
Subacc A: Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate >unknown phase] by in-situ chlorophyll fluorometer
Subacc B: Instrument output (voltage) by in-situ Aquatracka chlorophyll fluorometer
Subacc A: CPHLPR01
Subacc B: FVLTAQ01
Subacc A: mg/m 3
Subacc B: Volts
-
tran Subacc A: percent
Subacc B: volts
Subacc A: Transmittance (red light wavelength) per 25cm of the water body by 25cm path length red light transmissometer
Subacc B: Instrument output (voltage) by 25cm path length red light transmissometer
Subacc A: POPTDR01
Subacc B: TVLTDR01
Subacc A: percent
Subacc B: volts
-
oxygen Subacc A: µmol/l
Subacc B: ml/l
Concentration of oxygen {O2} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ sensor DOXYZZ01 Micromoles per litre Unit conversion handled automatically by transfer for both subaccessions
- - Saturation of oxygen {O2} in the water body OXYSSC01 % Calculated by the BODC transfer
- - Potential temperature of the water body by computation using UNESCO 1983 algorithm POTMCV01 Degrees Celsius Calculated by the BODC transfer
- - Sigma-theta of the water body by CTD and computation from salinity and potential temperature using UNESCO algorithm SIGTPR01 Kilograms per cubic metre Calculated by the BODC transfer

Following transfer the data were screened using BODC in-house visualisation software. A small number of suspect data values were identified during screening and assigned a BODC data quality flag.

Originator's Data Processing

Sampling strategy

The FISHES 2001 (DI253) cruise repeated the occupation of a number of hydrographic lines between Scotland and Iceland and carried out detailed multidisciplinary surveys of the northern ends of the Iceland Basin (including the Iceland Faeroes Front - IFF) and Rockall Trough to resolve both basin- and meso-scale physical, chemical and biological structure. In total, 156 CTD casts were completed.

Data Acquisition and Initial Processing

The data were processed using PEXEC (pstar) routines. Further details on the processing can be found in the cruise report . The data were calibrated post-cruise.

The processed data, together with the raw Sea-Bird, configuration and bottle files, were supplied to BODC for banking.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name D253
Departure Date 2001-05-04
Arrival Date 2001-06-20
Principal Scientist(s)John T Allen (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
DY078 6-28 May 2017 RRS Discovery

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

Other Series linked to this Fixed Station for this cruise - 670471 670483 670495 670502 670514 670526 670538 670551 670563 670575 670587 670599 670606 670618 670631 670643 670655 670667 670815 676779 676780 676792 676811 676823 676835 676847 676859 676860 676872 676884 676896 676903 676915 676927 676939 676940 676952 676964 1220848 1220861

Other Cruises linked to this Fixed Station (with the number of series) - 0508S (58) 0700S (30) 0703S (20) CD176 (40) D223A (22) D230 (65) D233 (49) D242 (89) D245 (25) 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 NameEllett Line
CategoryOffshore route/traverse

Ellett Line

The Ellett Line is a hydrographic transect consisting of 35 individual fixed stations which were occupied, usually at least once a year, between 1975 and 1996. The time series is named after the scientist David Ellett, who coordinated the survey work at Dunstaffnage Marine Laboratory (DML), near Oban. The transect ran between the north west coast of Scotland to the small outcrop of Rockall, via the Anton Dohrn Seamount - a prominent bathymetric feature in the Rockall Trough (see map). STD/CTD dips and associated water sampling for the analysis of nutrients were routinely performed during each station occupation.

In 1996 the transect was lengthened to incorporate new additional fixed stations crossing the Iceland Basin from Rockall to Iceland. This transect, which is still routinely occupied annually, is now known as the Extended Ellett Line and is a collaborative effort between scientists at Dunstaffnage Marine Laboratory and the Southampton site of the National Oceanography Centre (NOC).

Map of standard stations (1975-1996)

BODC image

Map produced using the GEBCO Digital Atlas

The white triangles indicate the nominal positions of the Ellett Line stations (1975- 1996). Measurements made along the Ellett Line lie within a box bounded by co-ordinates 56° 40.02' N, 13° 42.0' W at the south west corner and 57° 37.2' N, 6° 7.98' W at the north east corner.

Nominal Ellett Line stations (1975-1996)

Listed below are nominal details of the standard hydrographic stations that formed the Ellett Line between 1975 and January 1996.

Station Latitude Longitude Depth Range
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
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

History of Ellett Line occupations (1975-January 1996)

BODC Cruise Identifier Cruise Dates Ship
CH3/75 4-13 March 1975 RRS Challenger
CH7A/75 1-6 May 1975 RRS Challenger
CH10A/75 4-10 July 1975 RRS Challenger
CH12A/75 26 August-2 September 1975 RRS Challenger
CH14A/75 7-12 November 1975 RRS Challenger
CH5A/76 29 March-5 April 1976 RRS Challenger
CH8/76 19 May-1 June 1976 RRS Challenger
CH12/76 4-15 August 1976 RRS Challenger
CH15/76 7-16 October 1976 RRS Challenger
CH17/76 7-20 December 1976 RRS Challenger
CH4/77 25 February-11 March 1977 RRS Challenger
CH6B/77 14-19 April 1977 RRS Challenger
CH10/77 29 June-10 July 1977 RRS Challenger
CH11/77 12-26 July 1977 RRS Challenger
CH13/77 20 August-3 September 1977 RRS Challenger
CH2/78 30 January-13 February 1978 RRS Challenger
CH6/78 11-21 April 1978 RRS Challenger
CH9/78 31 May-10 June 1978 RRS Challenger
CH11B/78 29 July-12 August 1978 RRS Challenger
CH11D/78 3-17 September 1978 RRS Challenger
CH14B/78 4-11 November 1978 RRS Challenger
CH7/79 10-23 May 1979 RRS Challenger
S5/79 19 June-2 July 1979 RRS Shackleton
CH13/79 11-16 September 1979 RRS Challenger
CH16/79 28 October-11 November 1979 RRS Challenger
CH4/80 26 February-7 March 1980 RRS Challenger
CH7/80 21 April-6 May 1980 RRS Challenger
CH2/81 26 January-4 February 1981 RRS Challenger
CH6A/81 CH6B/81 6-25 April 1981 RRS Challenger
CH10/81 4-14 July 1981 RRS Challenger
CH15/81 6-20 October 1981 RRS Challenger
CH7A/82 CH7B/82 26 April-16 May 1982 RRS Challenger
CH15/82 16-30 October 1982 RRS Challenger
CH7B/83 23 May-2 June 1983 RRS Challenger
CH11/83 10-24 August 1983 RRS Challenger
CH2/84 23 June-8 July 1984 RRS Challenger
CH10/84 16 November-6 December 1984 RRS Challenger
CH1/85 20 January-5 February 1985 RRS Challenger
CH4/85 2-16 May 1985 RRS Challenger
CH8/85 14-28 August 1985 RRS Challenger
CH9 8-22 January 1987 RRS Challenger
CH14 24 April-7 May 1987 RRS Challenger
CH22 23 November-5 December 1987 RRS Challenger
CH25 24 February-7 March 1988 RRS Challenger
CH30 6-23 June 1988 RRS Challenger
D180 20 January-4 February 1989 RRS Discovery
LF1/89 5-11 May 1989 RV Lough Foyle
LF2/89 4-10 August 1989 RV Lough Foyle
CD44 24 November-2 December 1989 RRS Charles Darwin
CH67A 21-29 June 1990 RRS Challenger
CH71A 29 August-5 September 1990 RRS Challenger
CH75B 23 February-3 March 1991 RRS Challenger
CH81 1-8 July 1991 RRS Challenger
CH97 25 September-6 October 1992 RRS Challenger
CH101B 13-20 March 1993 RRS Challenger
CH103 12-24 May 1993 RRS Challenger
CH105 3-16 September 1993 RRS Challenger
CH110 10-20 March 1994 RRS Challenger
CH112 28 April-13 May 1994 RRS Challenger
CH114 15-29 August 1994 RRS Challenger
CH116 17-29 November 1994 RRS Challenger
CD92B 13 April-2 May 1995 RRS Charles Darwin
CH120 18 July-6 August 1995 RRS Challenger
CH124 8-27 January 1996 RRS Challenger

Other Series linked to this Fixed Station for this cruise - 676779 676780 676792 676811 676823 676835 676847 676859 676860 676872 676884 676896 676903 676915 676927 676939 676940 676952 676964 1220848 1220861

Other Cruises linked to this Fixed Station (with the number of series) - 0508S (58) 0700S (30) 0703S (20) CD176 (32) CD44 (34) CD92B (47) CH1/85 (19) CH10/77 (3) CH10/81 (21) CH10/84 (22) CH101B (13) CH103 (37) CH105 (34) CH10A/75 (15) CH11/77 (28) CH11/83 (35) CH110 (19) CH112 (35) CH114 (31) CH116 (25) CH11B/78 (26) CH11D/78 (14) CH120 (28) CH124 (46) CH12A/75 (3) CH13/77 (19) CH13/79 (17) CH14 (29) CH14A/75 (21) CH14B/78 (17) CH15/80 (8) CH15/81 (16) CH16/79 (13) CH2/78 (32) CH2/81 (13) CH2/82 (4) CH2/84 (29) CH22 (14) CH25 (18) CH3/83 (1) CH30 (23) CH4/77 (19) CH4/80 (29) CH4/85 (30) CH5A/76 (18) CH6/78 (25) CH63_2 (5) CH67A (27) CH6A/81 (14) CH6B/77 (24) CH6B/81 (20) CH7/79 (18) CH7/80 (16) CH71A (32) CH74A_1 (13) CH75B (31) CH7A/75 (24) CH7A/82 (24) CH7B/82 (13) CH7B/83 (29) CH8/76 (27) CH8/85 (30) CH81 (30) CH86B (8) CH89B (9) CH9 (25) CH9/78 (22) CH97 (30) CH9B/80 (10) D180 (30) D223A (22) D230 (21) D233 (20) D242 (45) D245 (25) D312 (34) D321B (28) D340A (34) D351 (34) D365 (55) D379 (36) DSK1/86 (10) DY052 (74) FR13/85 (12) FR13/87 (2) FR14B/87 (2) FR18/87 (11) FR7B/86 (6) FR8/86 (13) JC086 (35) JR20140531 (JR302) (37) LF1/89 (29) LF2/89 (30) PO300_2 (31) PO314 (30) S5/79 (8)


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