Metadata Report for BODC Series Reference Number 1084887

Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
Sea-Bird SBE 19plus SEACAT CTD  CTD; water temperature sensor; salinity sensor
Chelsea Instruments MINITracka II fluorometer  fluorometers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr James Fishwick
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Project(s) Western Channel Observatory 2002 - 2007

Data Identifiers

Originator's Identifier 050928_E1
BODC Series Reference 1084887

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2005-09-28 10:36
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 0.5 metres

Spatial Co-ordinates

Latitude 50.03300 N ( 50° 2.0' N )
Longitude 4.36700 W ( 4° 22.0' W )
Positional Uncertainty 0.5 to 1.0 n.miles
Minimum Sensor Depth 2.0 m
Maximum Sensor Depth 52.5 m
Minimum Sensor Height 22.5 m
Maximum Sensor Height 73.0 m
Sea Floor Depth 75.0 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 Chart reference - Depth extracted from available chart


BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
DEPHPR01 1 Metres CmpDep Depth below surface of the water body by profiling pressure sensor and converted to seawater depth using UNESCO algorithm
FVLTZZ01 1 Volts FlVolt Voltage of instrument output by in-situ chlorophyll fluorometer
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 Quality Document

Temperature, salinity and sigma-theta:

On the whole the trends appear reasonable for the location and time of year that the casts were made. Casts which displayed unrealistic values for the location and time of the year have been flagged accordingly. Once in 2002, 2003 and 2008, entire profiles had to be flagged. A specific problem report has been created for these casts to highlight the problem. Users should be aware that the salinity channel was sometimes noisy, particularly close to the surface or in the vicinity of strong gradients. This was particularly strong in casts collected in 2005.

Fluorometer voltage:

The fluorometer output which was labelled as a voltage channel in the originators' files was sometimes in excess of the maximum voltage of 4 volts specified in the manufacturer's specification sheet. Nevertheless the overall trends including occasional strong vertical variability appear reasonable given the location and time of year. However on four occasions in April and May 2002 the fluorescence vertical profiles showed very low values and unrealistically low variability with depth for the time or year and hydrographic conditions. These were deemed suspect and flagged accordingly by BODC.

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

Instrument description

Make Model Serial number
Sea-Bird SBE19 plus 4307
Chelsea Technologies MiniTracka II 07-6310-003

Sea-Bird SBE 19 and SBE 19plus SEACAT Profiler CTDs

The SBE 19 SEACAT Profiler is a self-contained, battery powered, pumped CTD system designed to measure conductivity, temperature, and pressure in marine or fresh water environments to depths of 10,500 meters. It was replaced by the SBE 19 plus model in 2001. An updated version of this instrument is the SBE 19 plus V2, which incorporates an electronics upgrade and additional features, with six differentially amplified A/D input channels, one RS-232 data input channel, and 64 MB FLASH memory.

The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by titanium housing for depths up to 7000 m. It is typically used for CTD profiling although a conversion kit is available for mooring deployments. The CTD can also be attached to an SBE 36 CTD Deck Unit and Power/Data Interface Module (PDIM) for real-time operation on single-core armored cable up to 10,000 m.


Parameter SBE 19 SBE 19 plus

Range: -5 to +35 °C

Accuracy: 0.01 °C

Resolution: 0.001 °C

Calibration: +1 to +32 °C*

Range: -5 to +35 °C

Accuracy: 0.005 °C

Resolution: 0.0001 °C

Calibration: +1 to +32 °C*


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

Accuracy: 0.001 S m -1

Resolution: 0.0001 S m -1

Calibration: 0 to 7 S m -1 . Physical calibration over the range 1.4 - 6 S m -1 *

Range: 0 to 9 Sm -1

Accuracy: 0.0005

Resolution: 0.00005 (most oceanic waters, resolves 0.4 ppm in salinity); 0.00007 (high salinity waters, resolves 0.4 ppm in salinity); 0.00001 (fresh waters, resolves 0.1 ppm in salinity)

Calibration: 0 to 9 S m -1 . Physical calibration over the range 1.4 - 6 S m -1 *

Strain gauge pressure sensor

Range: 0 to100, 150, 300, 500, 1000, 1500, 3000, 5000, 10000 or 15000 psia

Accuracy: 0.25% of full scale range (100 - 1500 psia); 0.15% of full scale range (3000 - 15000 psia)

Resolution: 0.015% of full scale

Calibration: 0 to full scale in 20% steps

Range: 0 to 20, 100, 350, 1000, 2000, 3500 or 7000 m

Accuracy: 0.1% of full scale range

Resolution: 0.002% of full scale range

Calibration: ambient pressure to full scale range in 5 steps

*Measurements outside this range may be at slightly reduced accuracy due to extrapolation errors.

Options and accessories

Additional sensors can be attached to the CTD, including:

The standard SBE 5M pump may be replaced by an SBE 5P (plastic housing) or 5T (titanium housing) pump for use with dissolved oxygen and/or other pumped sensors. Further details can be found in the manufacturer's SBE 19 plus V2 instrument specification or the SBE 19 and SBE 19 plus user guides.

Chelsea Instruments MINItracka Fluorometer

The MINI tracka Fluorometer is an in-situ optical sensor that uses a single high intensity LED light source and, according to the manufacturer, is designed to enhance rejection of ambient daylight. The fluorometer provides a linear response between chlorophyll concentration and fluorometer voltage.

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

Sensor Specifications

  Chlorophyll-a Chlorophyll-a Rhodamine Amido Rhodamine Fluorescein
Excitation wavelengths 430/30 nm 470/30 nm 470/30 nm 425/30 nm 480/80 nm
Emission wavelength 685/30 nm 685/30 nm 590/45 nm 550/30 nm 530/30 nm
Concentration range 0.03-100 µg l -1 0.03-100 µg l -1 0.03-100 µg l -1 0.04-200 µg l -1 0.03-100 µg l -1
Resolution 0.01 µg l -1 0.01 µg l -1 0.01 µg l -1 0.025 µg l -1 0.01 µg l -1
Calibration standard Chlorophyll-a in acetone Chlorophyll-a in acetone      
  Nephelometer Phycoerythrin Phycocyanin
Excitation wavelengths 470/30 nm 530/30 nm 590/35nm
Emission wavelength 470/30 nm 580/30 nm 645/35 nm
Concentration range 0.04-100 FTU 0.03-100 µg l -1 0.03-100 µg l -1
Resolution 0.01 FTU 0.01 µg l -1 0.01 µg l -1
Mechanical   Electrical  
Body Size 149 mm long x 70 mm dia Input Voltage 7 to 40 VDC
Weight in Air 0.7 Kg Output Voltage 0 to 4 VDC (linear)
Weight in Water 0.15 Kg Power requirements 0.7 W typical
Depth Rating 600 m Signal : Noise 10,000 : 1 @ full scale

Data Processing

Originator's Sampling Strategy

These data were collected using a CTD rig deployed from PML research vessels.

Originator's Processing

The raw CTD data were processed using the Sea-Bird software. The data were provided in tab delimited format.

BODC post-processing and screening


The data were converted from tab delimited format into BODC internal format using BODC transfer function 401. During transfer the depth variable was converted to pressure using the routine 'sw_pres', a part of the Seawater toolbox, this used the method of Fofonoff and Millard Jr. (1983) using inputs of depth and latitude. The density parameter was not transferred by BODC as this is generated to a standard algorithm during BODC transfer.

The measured variables were mapped to BODC parameter codes shown in the table below:

Originator's Parameter Name Units Description BODC parameter code Units Comments
Tv290v Deg C Temperature of the water column TEMPST01 Deg C -
FlCM volts Raw fluorometer voltage FVLTZZ01 volts -
DepSM m Depth of the water column DEPHPR01 m -
Density00 kg m -3 Density of the water column by unknown algorithm - - Channel not transferred as generated during BODC transfer
Sal00 - Salinity of the water column PSALST01 - -
- - Pressure PRESPR01 dbar Calculated by BODC from depth and latitude
- - Sigma-theta SIGTPR01 kg m -3 Generated by BODC using Fofonoff and Millard (1983) algorithm with parameters PRESPR01, TEMPST01 and PSALST01.


Reformatted CTD data were transferred onto a graphics work station for visualisation using the in-house editor EDSERPLO. No data values were edited or deleted. Flagging was achieved by modification of the associated BODC quality control flag for suspect or null values.


The profiles were banked to the National Oceanographic Database (NODB) following BODC procedures.


Fofonoff, N.P. and Millard, R.C., 1983. Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science No. 44, 53pp.

Project Information

Western Channel Observatory (2002-2007)

Who funded the programme?

The Natural Environment Research Council (NERC) through PML core funding.

Who was involved in the programme?

The programme was a collaboration involving scientists at Plymouth Marine Laboratory (PML) and the Marine Biological Association of the United Kingdom (MBA).

What was the programme about?

The Western Channel Observatory (WCO) is situated in the Western English Channel and comprises of long-term sustained observations at a number of stations. These stations have been the basis of a series of hydrographic surveys carried out during the 20th Century by scientists at the Marine Biological Association in Plymouth. Station L4 (50o 15' N, 4o 13' W) is one of these hydrographic stations and has been regularly sampled by the PML Zooplankton Group for a range of parameters from 1988 (the L4 time-series). Station E1 (50o 02' N, 4o 22' W) further offshore from Plymouth, has been the focus of a long time series of hydrographic and plankton observations and is where the concept of the "Russell Cycle" was developed. It had been regularly sampled until the late 1980s and in 2002 sampling recontinued for a range of parameters complementing those already being collect at the L4 station. The inclusion of the historic data sets from the E1 and L5 stations, in some cases dating back to the early 1900s, formed the basis for the Western Channel Observatory. The aim of the Western Channel Observatory (WCO) became to draw together long-term in situ measurements made at L4 and E1, ecosystem modelling studies and Earth Observation (EO), and integrate these using web-based Geographic Information System (GIS) technology. By integrating these quantitative in situ measurements, modelling studies and EO the WCO aimed to elucidate changes that are occurring in the marine component of the Earth system. The WCO is an ideal location as:

The observatory was further expanded between 2002 and 2007 to include measurements that had not been made before at these stations.

When was the programme active?

The observatory expanded from the L4 time-series with the resumption of sampling at E1 in 2002 in connection with MECN. In 2007 continued funding was provided for the WCO under the Oceans 2025 programme Theme 10: Integration of Sustained Observations in the Marine Environment.

Brief summary of the programme fieldwork/data

The programme continued the L4 time-series of weekly zooplankton and phytoplankton measurements at station L4 from 1988. Monthly sampling, which had stopped in the late 1980s, resumed in 2002 at station E1 for hydrography and phyoplankton data, and at stations E1 and L5 for zooplankton and fish larvae data. In addition new data sets of pigment and optics measurements at station E1 began in 2002 and the PML meterological station was set up in 2003.


Data Activity or Cruise Information


Cruise Name PML050928
Departure Date 2005-09-28
Arrival Date 2005-09-28
Principal Scientist(s)Roger Harris (Plymouth Marine Laboratory)
Ship Unknown research vessel

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

Station NameWestern Channel Observatory E1
CategoryCoastal location
Latitude50° 2.00' N
Longitude4° 22.00' W
Water depth below MSL75.0 m

Western Channel Observatory station E1

The Western Channel Observatory (WCO) is situated in the Western English Channel and comprises of sustained long-term observations at a number of stations.

Station E1 is located south-west of Plymouth at 50° 2.00' N, 4° 22.00' W.

More information can be found on the Western Channel Observatory website.

Other Cruises linked to this Fixed Station (with the number of series) - D366 (D367) (2) MS070911 (1) MS071101 (1) MS140722 (1) PML020626 (1) PML020717 (1) PML020814 (1) PML021002 (1) PML021031 (1) PML021213 (1) PML030124 (1) PML030213 (1) PML030321 (1) PML030423 (1) PML030514 (1) PML030604 (1) PML030611 (1) PML030618 (1) PML030625 (1) PML030702 (1) PML030709 (1) PML030806 (1) PML030909 (1) PML040803 (1) PML040826 (1) PML041102 (1) PML041208 (1) PML050202 (1) PML050308 (1) PML050330 (1) PML050511 (1) PML050608 (1) PML050620 (1) PML050713 (1) PML050810 (1) PML050831 (1) PML050914 (1) PML051118 (1) PML060118 (1) PML060208 (1) PML060301 (1) PML060315 (1) PML061010 (1) PML061101 (1) PML070206 (1) PML070313 (1) PQ070417 (1) PQ070501 (1) PQ070605 (1) PQ070703 (1) PQ070731 (1) PQ080415 (1) PQ080429 (1) PQ080513 (1) PQ080520 (1) PQ080603 (1) PQ080617 (1) PQ080715 (1) PQ080822 (1) PQ080916 (1) PQ081008 (1) PQ081022 (1) PQ081104 (1) PQ081211 (1) PQ090107 (1) PQ090127 (1) PQ090211 (1) PQ090226 (1) PQ090311 (1) PQ090401 (1) PQ090415 (1) PQ090528 (1) PQ090609 (1) PQ090623 (1) PQ090723 (1) PQ090921 (1) PQ090930 (1) PQ091013 (1) PQ100127 (1) PQ100317 (1) PQ100428 (1) PQ100511 (1) PQ100617 (1) PQ100628 (1) PQ100720 (1) PQ100817 (1) PQ100901 (1) PQ100921 (1) PQ101014 (1) PQ101115 (1) PQ101214 (1) PQ110118 (1) PQ110308 (1) PQ110321 (1) PQ110407 (1) PQ110419 (1) PQ110517 (1) PQ110602 (1) PQ110628 (1) PQ110714 (1) PQ110809 (1) PQ110823 (1) PQ110922 (1) PQ111028 (1) PQ111107 (1) PQ111122 (1) PQ120113 (1) PQ120123 (1) PQ120228 (1) PQ120314 (1) PQ120427 (1) PQ120516 (1) PQ120612 (1) PQ120626 (1) PQ120710 (1) PQ120724 (1) PQ120808 (1) PQ120823 (1) PQ120904 (1) PQ120919 (1) PQ121009 (1) PQ121023 (1) PQ121106 (1) PQ121129 (1) PQ121211 (1) PQ130123 (1) PQ130212 (1) PQ130227 (1) PQ130320 (1) PQ130423 (1) PQ130501 (1) PQ130516 (1) PQ130604 (1) PQ130618 (1) PQ130702 (1) PQ130716 (1) PQ130807 (1) PQ130820 (1) PQ130903 (1) PQ130924 (1) PQ131015 (1) PQ131112 (1) PQ131126 (1) PQ140130 (1) PQ140219 (1) PQ140312 (1) PQ140410 (1) PQ140424 (1) PQ140514 (1) PQ140605 (1) PQ140617 (1) PQ140702 (1) PQ140819 (1) PQ140902 (1) PQ140916 (1) PQ140930 (1) PQ141014 (1) PQ141118 (1) PQ141201 (1) PQ150122 (1) PQ150210 (1) PQ150310 (1) PQ150325 (1) PQ150409 (1) PQ150430 (1) PQ150521 (1) PQ150604 (1) PQ150616 (1) PQ150701 (1) PQ150715 (1) PQ150730 (1) PQ150811 (1) PQ150903 (1) PQ150918 (1) PQ151020 (1) PQ151126 (1) SQ020516 (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