Metadata Report for BODC Series Reference Number 1020521


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 Aquatracka fluorometer  fluorometers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Denise Smythe-Wright
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) WOCE
UK WOCE
 

Data Identifiers

Originator's Identifier CTD13515
BODC Series Reference 1020521
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1998-05-24 14:43
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 2.0 decibars
 

Spatial Co-ordinates

Latitude 59.12967 N ( 59° 7.8' N )
Longitude 17.63850 W ( 17° 38.3' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 0.99 m
Maximum Sensor Depth 963.61 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
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 -
 

Parameters

BODC CODE Rank Units Short Title Title
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
DOXYPR01 1 Micromoles per litre WC_dissO2_Beck Concentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ Beckmann probe
OXYSBB01 1 Percent BKBeck Saturation of oxygen {O2 CAS 7782-44-7} in the water body [dissolved plus reactive particulate phase] by in-situ Beckmann probe and computation from concentration using Benson and Krause algorithm
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


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

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 .

RRS Discovery Cruise D233 CTD Instrumentation

The CTD profiles were taken with a WOCE Standard Neil Brown Systems MkIIIc CTD (DEEP04), with a FSI 24 bottle rosette.

Sensor Manufacturer/Model Serial Number Last calibration date Comments
CTD Neil Brown MkIIIc DEEP04 - Incorporating an oxygen sensor
Fluorometer Chelsea Instruments Aquatracka 88/2360/108 - -
Transmissometer Sea Tech transmissometer (1 m pathlength) 161/2642/003 - Cruise reported stated this to be a Chelsea Instruments Transmissometer
Altimeter Simrad 200 m range - -
LADCP RDI (150 kHz) - 30 degree beam - - -
Reversing thermometers SIS T401 - Failed after stations 13415 and 13416
T989 - Lost at station 13462
T995 - -
T714 - Failed after stations 13415 and 13416
Reversing pressure meters SIS P6075 - Sensor failed on station 13440
P6394 - -
P6132 - Lost at station 13462

Aquatracka fluorometer

The Chelsea Instruments Aquatracka is a logarithmic response fluorometer. It uses a pulsed (5.5 Hz) xenon light source discharging between 320 and 800 nm through a blue filter with a peak transmission of 420 nm and a bandwidth at half maximum of 100 nm. A red filter with sharp cut off, 10% transmission at 664 nm and 678 nm, is used to pass chlorophyll-a fluorescence to the sample photodiode.

The instrument may be deployed either in a through-flow tank, on a CTD frame or moored with a data logging package.

Further details can be found in the manufacturer's specification sheet .

RRS Discovery Cruise D233 CTD Processing

Introduction

CTD profile data are presented from the CHAOS (Chemical and Hydrographic Atlantic Ocean Survey) cruise Discovery 233, as reported by Smythe-Wright (1999).

Originator's Data Processing

BODC Processing

References

Smythe-Wright, D. (1999). RRS Discovery Cruise 233. Southampton Oceanography Centre, Cruise Report No. 24, 86pp.

Owens, W.B., Millard, R.C. (1985). A new algorithm for CTD oxygen calibration. Journal of Physical Oceanography, 15(5), 621-631.


Project Information

World Ocean Circulation Experiment (WOCE)

The World Ocean Circulation Experiment (WOCE) was a major international experiment which made measurements and undertook modelling studies of the deep oceans in order to provide a much improved understanding of the role of ocean circulation in changing and ameliorating the Earth's climate.

WOCE had two major goals:


UK WOCE

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

Cruise

Cruise Name D233
Departure Date 1998-04-23
Arrival Date 1998-06-01
Principal Scientist(s)Denise Smythe-Wright (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 - 1020404 1020416 1020428 1020441 1020453 1020465 1020477 1020489 1020490 1020508 1020533 1020557 1020569 1020570 1020582 1020594 1020601 1020613 1020625 1020637 1020649 1020650 1020674 1020686 1306070 1306082 1306094 1306101 1306113 1306125 1306137 1306149 1306150 1306162 1306174 1306198 1306205 1306217 1306229 1306230 1306242 1306254 1306266 1306278 1306291 1306309 1306322 1306334

Other Cruises linked to this Fixed Station (with the number of series) - 0508S (58) 0700S (30) 0703S (20) CD176 (40) D223A (22) D230 (65) 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 IB7
CategoryOffshore location
Latitude59° 7.02' N
Longitude17° 40.02' W
Water depth below MSL1000.0 m

Extended Ellett Line: Fixed Station IB7

Station IB7 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 - 1306174

Other Cruises linked to this Fixed Station (with the number of series) - D230 (2) D242 (2) D321 (D321A) (1) D340A (1) D351 (1) D365 (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