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Metadata Report for BODC Series Reference Number 1034621


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Sea-Bird SBE 25 Sealogger CTD  CTD; water temperature sensor; salinity sensor
WETLabs C-Star transmissometer  transmissometers
WETLabs ECO-FLNTU combined fluorometer and turbidity sensor  fluorometers; optical backscatter sensors
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Mr George Slesser
Originating Organization Marine Scotland Aberdeen Marine Laboratory
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -
 

Data Identifiers

Originator's Identifier SC07/09/236
BODC Series Reference 1034621
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-05-21 09:03
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars
 

Spatial Co-ordinates

Latitude 59.86933 N ( 59° 52.2' N )
Longitude 5.73850 W ( 5° 44.3' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 1.98 m
Maximum Sensor or Sampling Depth 706.06 m
Minimum Sensor or Sampling Height 9.94 m
Maximum Sensor or Sampling Height 714.02 m
Sea Floor Depth 716.0 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling 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 CODERankUnitsTitle
ACYCAA011DimensionlessSequence number
ATTNMR011per metreAttenuation (red light wavelength) per unit length of the water body by 20 or 25cm path length transmissometer
CNCLCCI11Siemens per metreElectrical conductivity of the water body by in-situ conductivity cell and calibration against independent measurements
CPHLPS011Milligrams per cubic metreConcentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >unknown phase] by in-situ chlorophyll fluorometer and calibration against sample data
PRESPR011DecibarsPressure (spatial coordinate) exerted by the water body by profiling pressure sensor and correction to read zero at sea level
PSALST011DimensionlessPractical salinity of the water body by CTD and computation using UNESCO 1983 algorithm
TEMPST011Degrees CelsiusTemperature 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

FRV Scotia 0709S part b Data quality report

The attenuation and chlorophyll channels contain a significant proportion of noisy data.

These data should be used with caution.


Data Access Policy

Public domain 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.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."


Narrative Documents

Instrument Description

CTD Unit and Auxiliary Sensors

A Sea-Bird Electronics SBE 25 Sealogger CTD unit was used. Water samples were collected with a SBE 35 Carousel, which was attached to the CTD frame. The CTD unit included the following sensors.

Sensor Manufacturer Model Serial number Calibration date
Pressure Sea-Bird   0232 2003-02-19
Temperature Sea-Bird   1696 2009-02-03
Conductivity Sea-Bird   1454 2009-02-03
Fluorometer WetLabs ECO-FL FLRTD-064 2003-11-08
Transmissometer Wet Labs C-Star CST-704DR 2003-08-25

Sea-Bird SBE 25 SEALOGGER CTD

The SBE 25 SEALOGGER is a research-quality CTD profiling system used for coastal, estuarine and, can also be a practical option, for deep-water work. It is easily configured in the field for a wide range of auxiliary sensors. The SEALOGGER is self-powered, requires no conductive cable, and is designed for use up to 6800 meters (10,000 psia). It uses the SBE3F temperature and SBE4 conductivity sensors as well as having an external strain gauge pressure sensor. It provides pump-controlled T-C ducted flow, samples at 8 Hz, records internally and provides simultaneous real-time data via its built-in RS-232 interface.

The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by aluminium housing for depths up to 6800 m.

Specifications

Parameter SBE 25
Temperature

Range: -5 to +35 °C

Accuracy: 0.002 °C

Resolution: 0.0003 °C

Conductivity

Range: 0 to 7 S m-1 (0 to 70 mmho cm-1)

Accuracy: 0.0003 S m-1

Resolution: 0.00004 S m-1

Strain gauge pressure sensor

Range: 0 to 20, 100, 350, 600, 1000, 2000, 3500, 7000 metres (expressed in metres of deployment depth capability)

Accuracy: 0.1% of full scale range

Resolution: 0.015% of full scale range

Options and accessories

Additional sensors can be attached to the CTD, including:

  • Dissolved Oxygen (SBE 43 DO Sensor)
  • pH (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor)
  • fluorescence
  • radiance (PAR)
  • light transmission
  • optical backscatter (turbidity)

The SBE 5T titanium pump can be used in place of SBE 5P pump. Further details can be found in the manufacturer's SBE 25 instrument specification.

WETLabs ECO FLNTU fluorescence and turbidity sensor

The Environmental Characterization Optics (ECO) Fluorometer and Turbidity (FLNTU) sensor is a dual wavelength, single-angle instrument that simultaneously determines chlorophyll fluorescence and turbidity. It is easily integrated in CTD packages and provides a reliable turbidity measurement that is not affected by Colored Dissolved Organic Matter (CDOM) concentration.

The FLNTU can operate continuously or periodically and has two different types of connectors to output the data. There are 5 other models that operate the same way as this instrument but have slight differences, as stated below:

  • FLNTU(RT) - has an analog an RS-232 serial output and operates continuously, when power is supplied
  • FLNTU(RT)D - similar to the FLNTU(RT) but has a depth rating of 6000 m
  • FLNTUB - has internal batteries for autonomous operation
  • FLNTUS - has an integrated anti-fouling bio-wiper
  • FLNTUSB - has the same characteristics as the FLNTUS but with internal batteries for autonomous operation

Specifications

Temperature range 0 to 30°C
Depth rating

600 m (standard)

6000 m (deep)

Turbidity
Wavelength 700 nm
Sensitivity 0.01 NTU
Typical range 0.01 to 25 NTU
Fluorescence
Wavelength 470 nm (excitation), 695 nm (emission)
Sensitivity 0.01 µg L-1
Typical range 0.01 to 50 µg L-1
Linearity 99% R2

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

WETLabs C-Star transmissometer

This instrument is designed to measure beam transmittance by submersion or with an optional flow tube for pumped applications. It can be used in profiles, moorings or as part of an underway system.

Two models are available, a 25 cm pathlength, which can be built in aluminum or co-polymer, and a 10 cm pathlength with a plastic housing. Both have an analog output, but a digital model is also available.

This instrument has been updated to provide a high resolution RS232 data output, while maintaining the same design and characteristics.

Specifications

Pathlength 10 or 25 cm
Wavelength 370, 470, 530 or 660 nm
Bandwidth

~ 20 nm for wavelengths of 470, 530 and 660 nm

~ 10 to 12 nm for a wavelength of 370 nm

Temperature error 0.02 % full scale °C-1
Temperature range 0 to 30°C
Rated depth

600 m (plastic housing)

6000 m (aluminum housing)

Further details are available in the manufacturer's specification sheet or user guide.

BODC Processing

Data were received by BODC in one ASCII format file that was subsequently split into 119 separate files, one for each CTD profile. The series were reformatted to the internal QXF format using BODC transfer function 340. Sample calibrations were applied to the conductivity data. The following table details mapping of variables to BODC parameter codes.

Original parameter name Original Units Description BODC Parameter Code BODC Units Comments
Pressure Decibars Pressure exerted by the water column PRESPR01 Decibars  
Temperature °C Temperature of the water column TEMPST01 °C  
Conductivity mS cm -1 Electrical conductivity of the water column calibrated against independent measurements CNCLCCI1 S m -1 Conversion by transfer (mS cm -1 x 0.1). Sample calibrations applied by transfer.
Salinity   Salinity of the water column PSALST01 Dimensionless Derived by transfer using UNESCO 1983 algorithm
Fluorescence µg l -1 In-situ fluorescence CPHLPS01 mg m -3  
Attenuation volts Transmissivity of the water column ATTNMR01 m-1  
Oxygen ml l-1 Oxygen concentration DOXYSU01 µMoles l -1 Conversion by transfer (ml l-1 x 44.66)
Oxygen saturation % Percentage oxygen saturation of the water column OXYSZZ01 %  

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged. Flags from the originator marking suspect data were retained during transfer.

Originator's Data Processing

Sampling Strategy

A total of 119 CTD casts were performed on FRV Scotia cruise 0709S part b (21 May 2009 - 01 June 2009) at locations along the shelf edge to the north and west of Scotland. The data were collected between 03:38 hours on 21 May 2009 and 11:07 hours on 01 June 2009.

Water samples were collected in order to obtain independent salinity and fluoresence measurements. The sample data were used to derive calibrations for the conductivity and fluoresence profiles collected by the CTD.

Data Processing

The raw CTD data files were processed through the SeaBird Electronics SeaSoft data processing software following standard procedures. The originators used in-house interactive visual display editing software to edit out individual spikes in the primary temperature and conductivity channels. In addition, a low-pass filter (Sy 1985) was applied to particularly noisy data. An ASCII file was generated for each CTD cast and all files from a cruise were concatenated into one ASCII file which was submitted to BODC.

Sy A., 1985. An alternative editing technique for oceanographic data. Deep Sea Research Part A: Oceanographic Research Papers, 32 (12), 1591-1599.

Field Calibrations

Independent salinity and fluoresence samples, obtained from the sample bottle and spread throughout the cruise, were used to calibrate the CTD conductivity and fluoresence data. Outlying points were discarded, and between 25 and 84 data points were used to derive the calibrations. The sample analyses yielded a straight line conductivity calibration of the form y = mx + c, where m = 0.999606 and c = 0.009397 (conductivity) and where m = 0.005222 and c = -0.783526 (fluoresence).

Parameter Value of m (y=mx+c) Value of c (y=mx+c) Equation
Conductivity 0.999606 0.009397 C(cal) = 0.999606C(obs) + 0.009397
Fluoresence 0.005222 -0.783526 C(cal) = 0.005222C(obs) - 0.783526

The calibrated and uncalibrated data were submitted to BODC, who applied the appropriate corrections.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name 0709S
Departure Date 2009-05-15
Arrival Date 2009-06-02
Principal Scientist(s)George Slesser (Marine Scotland Aberdeen Marine Laboratory)
Ship FRV Scotia

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameFaroe-Cape Wrath Transect
CategoryOffshore route/traverse

Faroe-Cape Wrath Transect

The Faroe-Cape Wrath transect was started for the THOR (Thermohaline Overturning - at Risk?) project (2007-2013) and has now continued under NACLIM (North Atlantic Climate Variability) project (2012-2017), both projects ran under European Union (EU) Seventh Framework Programme (FP7).

Marine Scotland first sampled the transect in May 2009. Marine Scotland hope to sample this line twice a year (April-May and September-October) and if possible in December.

The stations along this line will be mainly used for CTD deployments although salinity samples will be taken along the line for calibration purposes. Some nutrient samples have been taken by Marine Scotland but it is not anticipated that nutrient sampling will become a regular occurrence.

The Faroese are also sampling this line.

Map of standard stations

BODC image

Line Stations

Listed below are details of the standard hydrographic stations that form the Faroe-Cape Wrath line.

Station Name Latitude Longitude Depth (m) Spacing (nm)
FWZ-19 59° 30.00' N 06° 10.00' W 152 -
FWZ-18 59° 34.82' N 06° 10.00' W 196 4.81
FWZ-17 59° 39.64' N 06° 10.00' W 220 4.81
FWZ-16 59° 44.45' N 06° 10.00' W 277 4.80
FWZ-15 59° 49.27' N 06° 10.00' W 457 4.81
FWZ-14 59° 54.09' N 06° 10.00' W 600 4.81
FWZ-13 59° 58.91' N 06° 10.00' W 970 4.81
FWZ-12 60° 03.73' N 06° 10.00' W 1082 4.81
FWZ-11 60° 08.54' N 06° 10.00' W 1195 4.80
FWZ-10 60° 12.76' N 06° 10.00' W 1212 4.21
FWZ-09 60° 18.18' N 06° 10.00' W 616 5.41
FWZ-08 60° 23.00' N 06° 10.00' W 423 4.81
FWZ-07 60° 30.63'N 06° 13.88'W 302 7.86
FWZ-06 60° 38.26'N 06° 17.77'W 275 7.86
FWZ-05 60° 45.89'N 06° 21.69'W 184 7.86
FWZ-04 60° 53.52'N 06° 25.65'W 138 7.86
FWZ-03 61° 01.14'N 06° 29.63'W 142 7.85
FWZ-02 61° 08.76'N 06° 33.65'W 125 7.85
FWZ-01 61° 16.38' N 06° 37.70' W 100 7.86
- - - Totals 107.12

Faroe - Cape Wrath (extended line)

This line is not shown on the map but may be sampled occasionally.

Station Name Latitude Longitude Depth (m) Spacing (nm)
FWZ-29 58° 36.60' N 06° 13.09' W 112 -
FWZ-28 58° 42.06' N 06° 12.18' W 116 5.5
FWZ-27 58° 47.42' N 06° 11.72' W 116 5.4
FWZ-26 58° 52.75' N 06° 11.71' W 113 5.4
FWZ-25 58° 58.02' N 06° 13.41' W 74 5.3
FWZ-24 59° 03.36' N 06° 14.34' W 63 5.4
FWZ-23 59° 08.61' N 06° 14.18' W 106 5.3
FWZ-22 59° 13.84' N 06° 12.02' W 113 5.3
FWZ-21 59° 19.21' N 06° 11.39' W 148 5.4
FWZ-20 59° 24.58' N 06° 10.58' W 155 5.4
- - - Totals 48.4

CTD sampling history

Cruise FRV Scotia 0512S, between 07 May 2012 - 22 May 2012, sampled stations FWZ-01 to FWZ-19 inclusively.

Related Fixed Station activities are detailed in Appendix 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
Q value below limit of quantification

Appendix 1: Faroe-Cape Wrath Transect

Related series for this Fixed Station 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
1034577CTD or STD cast2009-05-21 03:38:0059.36033 N, 5.43383 WFRV Scotia 0709S
1034589CTD or STD cast2009-05-21 05:08:0059.53183 N, 5.59 WFRV Scotia 0709S
1034590CTD or STD cast2009-05-21 06:26:0059.6775 N, 5.63067 WFRV Scotia 0709S
1034608CTD or STD cast2009-05-21 07:43:0059.77233 N, 5.71533 WFRV Scotia 0709S
1034633CTD or STD cast2009-05-21 10:47:0059.9645 N, 5.80433 WFRV Scotia 0709S
1034645CTD or STD cast2009-05-21 12:48:0060.08433 N, 5.87983 WFRV Scotia 0709S
1034657CTD or STD cast2009-05-21 14:57:0060.21917 N, 5.95467 WFRV Scotia 0709S
1034669CTD or STD cast2009-05-21 16:51:0060.3085 N, 6.004 WFRV Scotia 0709S
1034670CTD or STD cast2009-05-21 18:21:0060.3985 N, 6.062 WFRV Scotia 0709S
1034682CTD or STD cast2009-05-21 20:22:0060.617 N, 6.2 WFRV Scotia 0709S
1034694CTD or STD cast2009-05-21 22:38:0060.89083 N, 6.3625 WFRV Scotia 0709S
1034701CTD or STD cast2009-05-22 00:28:0061.14117 N, 6.51317 WFRV Scotia 0709S
1180181CTD or STD cast2012-05-10 16:10:0059.49933 N, 6.1675 WFRV Scotia 0512S
1180193CTD or STD cast2012-05-10 17:19:0059.58033 N, 6.167 WFRV Scotia 0512S
1180200CTD or STD cast2012-05-10 18:19:0059.65933 N, 6.1695 WFRV Scotia 0512S
1180212CTD or STD cast2012-05-10 19:17:0059.73967 N, 6.17 WFRV Scotia 0512S
1180224CTD or STD cast2012-05-11 13:13:0059.82117 N, 6.16583 WFRV Scotia 0512S
1180236CTD or STD cast2012-05-11 14:41:0059.90167 N, 6.16717 WFRV Scotia 0512S
1180248CTD or STD cast2012-05-11 16:29:0059.9815 N, 6.16633 WFRV Scotia 0512S
1180261CTD or STD cast2012-05-11 18:32:0060.06183 N, 6.16417 WFRV Scotia 0512S
1180273CTD or STD cast2012-05-11 20:19:0060.143 N, 6.16483 WFRV Scotia 0512S
1180285CTD or STD cast2012-05-11 22:18:0060.21333 N, 6.16783 WFRV Scotia 0512S
1180297CTD or STD cast2012-05-12 00:23:0060.306 N, 6.17067 WFRV Scotia 0512S
1180304CTD or STD cast2012-05-12 01:53:0060.38583 N, 6.16867 WFRV Scotia 0512S
1180316CTD or STD cast2012-05-12 03:27:0060.50883 N, 6.2315 WFRV Scotia 0512S
1180328CTD or STD cast2012-05-12 04:59:0060.638 N, 6.297 WFRV Scotia 0512S
1180341CTD or STD cast2012-05-12 06:20:0060.76467 N, 6.3645 WFRV Scotia 0512S
1180353CTD or STD cast2012-05-12 07:31:0060.89267 N, 6.43133 WFRV Scotia 0512S
1180365CTD or STD cast2012-05-12 08:41:0061.01917 N, 6.49683 WFRV Scotia 0512S
1180377CTD or STD cast2012-05-12 09:47:0061.14667 N, 6.563 WFRV Scotia 0512S
1180389CTD or STD cast2012-05-12 10:53:0061.274 N, 6.62633 WFRV Scotia 0512S