Metadata Report for BODC Series Reference Number 710327


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Sea-Bird SBE 13 Dissolved Oxygen Sensor  dissolved gas sensors
Sea-Bird SBE 911plus CTD  CTD; water temperature sensor; salinity sensor
Seapoint chlorophyll fluorometer  fluorometers
WETLabs C-Star transmissometer  transmissometers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Ms Sarah Hughes
Originating Organization Fisheries Research Services Aberdeen Marine Laboratory (now 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 SC07/05/154
BODC Series Reference 710327
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2005-05-09 03:05
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars
 

Spatial Co-ordinates

Latitude 60.49600 N ( 60° 29.8' N )
Longitude 1.00550 E ( 1° 0.3' E )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 1.98 m
Maximum Sensor or Sampling Depth 128.73 m
Minimum Sensor or Sampling Height 14.27 m
Maximum Sensor or Sampling Height 141.02 m
Sea Floor Depth 143.0 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
ATTNZS011per metreAttenuation (red light wavelength) per unit length of the water body by WET Labs transmissometer and calibration to read zero in clear water
CNDCST011Siemens per metreElectrical conductivity of the water body by CTD
CPHLPM011Milligrams 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 manufacturer's calibration applied
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
DOXYPR011Micromoles per litreConcentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ Beckmann probe
PRESPR011DecibarsPressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected 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


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

Sea Bird Electronics SBE13 Dissolved Oxygen Sensor

The SBE 13 was designed as an auxiliary sensor for Sea Bird SBE 9plus, but can fitted in custom instrumentation applications. When used with the SBE 9 Underwater Unit, a flow-through plenum improves the data quality, as the pumping water over the sensor membrane reduces the errors caused by oxygen depletion during the periods of slow or intermittent flushing and also reduces exposure to biofouling.

The output voltage is proportional to membrane current (oxygen current) and to the sensor element's membrane temperature (oxygen temperature), which is used for internal temperature compensation.

Two versions of the SBE 13 are available: the SBE 13Y uses a YSI polarographic element with replaceable membranes to provide in situ measurements up to 2000 m depth and the SBE 13B uses a Beckman polarographic element to provide in situ measurements up to 10500 m depth, depending on the sensor casing. This sensor includes a replaceable sealed electrolyte membrane cartridge.

The SBE 13 instrument has been out of production since 2001 and has been superseded by the SBE 43.

Specifications

Measurement range 0 to 15 mL L-1
Accuracy 0.1 mL L-1
Time response

2 s at 25°C

5 s at 0°C

Depth range

2000 m (SBE 13Y- housing in anodized aluminum)

6800 m (SBE 13B- housing in anodized aluminum)

105000 m (SBE 13B- housing in titanium)

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

Instrument Description

CTD Unit and Auxiliary Sensors

A Sea-Bird Electronics SBE19 SEACAT CTD unit was used. The CTD unit included the following sensors.

Sensor Manufacturer Serial number Calibration date
Pressure Sea-Bird 64240 2000-10-26
Temperature Sea-Bird 2041 2005-02-08
Conductivity Sea-Bird 1615 2005-02-08
Temperature Sea-Bird 2105 2005-02-08
Conductivity Sea-Bird 1669 2005-02-08
Oxygen Sea-Bird 0504 2003-08-05
ECO_FL Fluorometer Wet Labs FLRTD-064 2003-11-08
C-Star Transmissometer Wet Labs CST-704DR 2003-08-25

Calibrations

Independent water samples were used to calibrate the CTD conductivity and fluorescence data. The following calibration values were supplied to BODC, who applied them to the data as part of the transfer process. By applying the calibrations to the fluoresence values (V) the results are chlorophyll (a) in ug/l.

Parameter Value of m (y=mx+c) Value of c (y=mx+c) Equation
Conductivity 1.000051 -0.001987 C(cal) = 1.000051C(obs) -0.001987
Fluorescence 0.011872 -1.884138 Chl(a) = 0.011872F(V) -1.884138

Sea-Bird Electronics SBE 911 and SBE 917 series CTD profilers

The SBE 911 and SBE 917 series of conductivity-temperature-depth (CTD) units are used to collect hydrographic profiles, including temperature, conductivity and pressure as standard. Each profiler consists of an underwater unit and deck unit or SEARAM. Auxiliary sensors, such as fluorometers, dissolved oxygen sensors and transmissometers, and carousel water samplers are commonly added to the underwater unit.

Underwater unit

The CTD underwater unit (SBE 9 or SBE 9 plus) comprises a protective cage (usually with a carousel water sampler), including a main pressure housing containing power supplies, acquisition electronics, telemetry circuitry, and a suite of modular sensors. The original SBE 9 incorporated Sea-Bird's standard modular SBE 3 temperature sensor and SBE 4 conductivity sensor, and a Paroscientific Digiquartz pressure sensor. The conductivity cell was connected to a pump-fed plastic tubing circuit that could include auxiliary sensors. Each SBE 9 unit was custom built to individual specification. The SBE 9 was replaced in 1997 by an off-the-shelf version, termed the SBE 9 plus, that incorporated the SBE 3 plus (or SBE 3P) temperature sensor, SBE 4C conductivity sensor and a Paroscientific Digiquartz pressure sensor. Sensors could be connected to a pump-fed plastic tubing circuit or stand-alone.

Temperature, conductivity and pressure sensors

The conductivity, temperature, and pressure sensors supplied with Sea-Bird CTD systems have outputs in the form of variable frequencies, which are measured using high-speed parallel counters. The resulting count totals are converted to numeric representations of the original frequencies, which bear a direct relationship to temperature, conductivity or pressure. Sampling frequencies for these sensors are typically set at 24 Hz.

The temperature sensing element is a glass-coated thermistor bead, pressure-protected inside a stainless steel tube, while the conductivity sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Thermistor resistance or conductivity cell resistance, respectively, is the controlling element in an optimized Wien Bridge oscillator circuit, which produces a frequency output that can be converted to a temperature or conductivity reading. These sensors are available with depth ratings of 6800 m (aluminium housing) or 10500 m (titanium housing). The Paroscientific Digiquartz pressure sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.

Additional sensors

Optional sensors for dissolved oxygen, pH, light transmission, fluorescence and others do not require the very high levels of resolution needed in the primary CTD channels, nor do these sensors generally offer variable frequency outputs. Accordingly, signals from the auxiliary sensors are acquired using a conventional voltage-input multiplexed A/D converter (optional). Some Sea-Bird CTDs use a strain gauge pressure sensor (Senso-Metrics) in which case their pressure output data is in the same form as that from the auxiliary sensors as described above.

Deck unit or SEARAM

Each underwater unit is connected to a power supply and data logging system: the SBE 11 (or SBE 11 plus) deck unit allows real-time interfacing between the deck and the underwater unit via a conductive wire, while the submersible SBE 17 (or SBE 17 plus) SEARAM plugs directly into the underwater unit and data are downloaded on recovery of the CTD. The combination of SBE 9 and SBE 17 or SBE 11 are termed SBE 917 or SBE 911, respectively, while the combinations of SBE 9 plus and SBE 17 plus or SBE 11 plus are termed SBE 917 plus or SBE 911 plus.

Specifications

Specifications for the SBE 9 plus underwater unit are listed below:

Parameter Range Initial accuracy Resolution at 24 Hz Response time
Temperature -5 to 35°C 0.001°C 0.0002°C 0.065 sec
Conductivity 0 to 7 S m-1 0.0003 S m-1 0.00004 S m-1 0.065 sec (pumped)
Pressure 0 to full scale (1400, 2000, 4200, 6800 or 10500 m) 0.015% of full scale 0.001% of full scale 0.015 sec

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

Seapoint Chlorophyll Fluorometer

The Seapoint Chlorophyll Fluorometer (SCF) is a low power instrument for in situ measurements of chlorophyll a. The SCF uses modulated blue LED lamps and a blue excitation filter to excite chlorophyll a. The fluorescent light emitted by the chlorophyll a passes through a red emission filter and is detected by a silicon photodiode. The low level signal is then processed using synchronous demodulation circuitry which generates an output voltage proportional to chlorophyll a concentration. The SCF may be operated with or without a pump.

Sensor specifications, current at August 2006, are given in the table below. More information can be found at the manufacturer's web site.

Sensor Specifications

Power requirements 8 - 20 VDC, 15 mA avg., 27 mA pk.
Output 0 - 5.0 VDC
Output Time Constant 0.1 sec.
Power-up transient period < 1 sec.
Excitation Wavelength 470 nm CWL, 30 nm FWHM
Emission Wavelength 685 nm CWL, 30 nm FWHM
Sensing Volume 340 mm3
Minimum Detectable Level 0.02 µg l-1

  Gain Sensitivity, V µg-1 l-1 Range, µg l-1
Sensitivity/Range 30x
10x
3x
1x
1.0
0.33
0.1
0.033
5
15
50
150

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 seven separate files, one for each CTD profile. The series were reformatted to the internal QXF format using BODC transfer function 340. The following table details the 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 CNDCST01 S m-1 Conversion by transfer (mS cm-1 x 0.1)
Salinity Dimensionless Practical salinity of the water column by CTD and computation using UNESCO 1983 algorithm PSALST01 Dimensionless  
Fluorescence µg l-1 In-situ fluorescence with calibration against sample data CPHLPS01 mg m-3  
Fluorescence µg l-1 In-situ fluorescence and manufacturer's calibration applied CPHLPM01 mg m-3  
Beam attenuation m-1 Attenuance of the water column ATTNZS01 m-1  
Oxygen ml l-1 Dissolved oxygen DOXYPR01 µmol l-1 Conversion by transfer (ml l-1 x 44.6)

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

Originator's 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. 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.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name 0705S_1
Departure Date 2005-05-07
Arrival Date 2005-05-26
Principal Scientist(s)George Slesser (Fisheries Research Services Aberdeen Marine Laboratory)
Ship FRV Scotia

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameEast of Shetland Line 2
CategoryOffshore route/traverse

East of Shetland Line 2

The East of Shetland Line 2 consists of a line of sample stations east of Shetland, along latitude 60°30.00'N to the centre of the North Sea.

At present the Fisheries Research Services (FRS) monitors this line. These data provide information on long term variations in key variables.

Monitoring data include: Ocean profiles of temperature, salinity and nutrients.

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: East of Shetland Line 2

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
559321CTD or STD cast2000-05-20 21:00:0060.4983 N, 0.1667 EFRV Scotia 0700S
559333CTD or STD cast2000-05-20 21:43:0060.5 N, 0.0 WFRV Scotia 0700S
559345CTD or STD cast2000-05-20 22:27:0060.5 N, 0.1667 WFRV Scotia 0700S
559357CTD or STD cast2000-05-20 23:14:0060.5 N, 0.3317 WFRV Scotia 0700S
559369CTD or STD cast2000-05-21 00:01:0060.5 N, 0.4983 WFRV Scotia 0700S
559370CTD or STD cast2000-05-21 00:49:0060.4983 N, 0.6683 WFRV Scotia 0700S
559382CTD or STD cast2000-05-21 01:36:0060.4967 N, 0.835 WFRV Scotia 0700S
559394CTD or STD cast2000-05-21 02:09:0060.4983 N, 0.9167 WFRV Scotia 0700S
559401CTD or STD cast2000-05-21 02:44:0060.5017 N, 1.0 WFRV Scotia 0700S
710303CTD or STD cast2005-05-09 00:08:0060.4965 N, 1.66317 EFRV Scotia 0705S_1
710315CTD or STD cast2005-05-09 01:36:0060.4975 N, 1.33333 EFRV Scotia 0705S_1
710339CTD or STD cast2005-05-09 04:26:0060.49883 N, 0.66467 EFRV Scotia 0705S_1
710340CTD or STD cast2005-05-09 05:54:0060.50017 N, 0.33233 EFRV Scotia 0705S_1
710352CTD or STD cast2005-05-09 07:23:0060.4985 N, 1.7E-4 WFRV Scotia 0705S_1
710364CTD or STD cast2005-05-09 08:43:0060.50133 N, 0.336 WFRV Scotia 0705S_1
710376CTD or STD cast2005-05-09 09:27:0060.49917 N, 0.49667 WFRV Scotia 0705S_1
710388CTD or STD cast2005-05-09 10:09:0060.49917 N, 0.66033 WFRV Scotia 0705S_1
710407CTD or STD cast2005-05-09 17:13:0060.5 N, 0.83483 WFRV Scotia 0705S_1
710419CTD or STD cast2005-05-09 18:06:0060.49983 N, 1.0 WFRV Scotia 0705S_1
712819CTD or STD cast2005-09-29 17:34:0060.49933 N, 0.99483 EFRV Scotia 1405S
712820CTD or STD cast2005-09-29 18:55:0060.49933 N, 0.67167 EFRV Scotia 1405S
712832CTD or STD cast2005-09-29 20:22:0060.49983 N, 0.3385 EFRV Scotia 1405S
712844CTD or STD cast2005-09-29 21:47:0060.501 N, 0.00283 EFRV Scotia 1405S
712856CTD or STD cast2005-09-29 23:04:0060.50067 N, 0.33583 WFRV Scotia 1405S
712868CTD or STD cast2005-09-29 23:49:0060.499 N, 0.49983 WFRV Scotia 1405S
712881CTD or STD cast2005-09-30 00:39:0060.5 N, 0.66317 WFRV Scotia 1405S
712893CTD or STD cast2005-09-30 01:26:0060.50033 N, 0.83367 WFRV Scotia 1405S
712900CTD or STD cast2005-09-30 02:10:0060.49983 N, 0.999 WFRV Scotia 1405S
726551CTD or STD cast2006-10-09 06:09:0060.50067 N, 1.0 WFRV Scotia 1506S
726563CTD or STD cast2006-10-09 06:51:0060.5 N, 0.83383 WFRV Scotia 1506S
726575CTD or STD cast2006-10-09 07:40:0060.50017 N, 0.66933 WFRV Scotia 1506S
726587CTD or STD cast2006-10-09 08:33:0060.50267 N, 0.50417 WFRV Scotia 1506S
726599CTD or STD cast2006-10-09 09:23:0060.49983 N, 0.3355 WFRV Scotia 1506S
726606CTD or STD cast2006-10-09 10:36:0060.50133 N, 0.0015 WFRV Scotia 1506S
726618CTD or STD cast2006-10-09 11:49:0060.4995 N, 0.33483 EFRV Scotia 1506S
726631CTD or STD cast2006-10-09 13:12:0060.49967 N, 0.66617 EFRV Scotia 1506S
726643CTD or STD cast2006-10-09 14:32:0060.50083 N, 0.99683 EFRV Scotia 1506S
726655CTD or STD cast2006-10-09 15:43:0060.49917 N, 1.33183 EFRV Scotia 1506S
726667CTD or STD cast2006-10-09 17:04:0060.499 N, 1.667 EFRV Scotia 1506S
726679CTD or STD cast2006-10-09 17:51:0060.4995 N, 1.83117 EFRV Scotia 1506S
1036117CTD or STD cast2009-10-03 15:50:0060.50233 N, 1.66433 EFRV Scotia 1309S
1036129CTD or STD cast2009-10-03 17:13:0060.4995 N, 1.33267 EFRV Scotia 1309S
1036130CTD or STD cast2009-10-03 18:34:0060.49967 N, 0.998 EFRV Scotia 1309S
1036142CTD or STD cast2009-10-03 19:55:0060.4995 N, 0.66083 EFRV Scotia 1309S
1036154CTD or STD cast2009-10-03 21:18:0060.49883 N, 0.32767 EFRV Scotia 1309S
1036166CTD or STD cast2009-10-04 05:11:0060.49933 N, 0.009 WFRV Scotia 1309S
1036178CTD or STD cast2009-10-04 06:34:0060.5005 N, 0.33283 WFRV Scotia 1309S
1036191CTD or STD cast2009-10-04 07:21:0060.50083 N, 0.5045 WFRV Scotia 1309S
1036209CTD or STD cast2009-10-04 08:09:0060.49867 N, 0.66917 WFRV Scotia 1309S
1036210CTD or STD cast2009-10-04 09:05:0060.5005 N, 0.834 WFRV Scotia 1309S
1036222CTD or STD cast2009-10-04 09:58:0060.50067 N, 1.00067 WFRV Scotia 1309S