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Metadata Report for BODC Series Reference Number 251155


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Bissett-Bermann 9040 CTD system  CTD; water temperature sensor; salinity sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator -
Originating Organization Scottish Marine Biological Association (now Scottish Association for Marine Science)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -
 

Data Identifiers

Originator's Identifier C1487/125
BODC Series Reference 251155
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1987-05-05 05:17
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 56.08160 N ( 56° 4.9' N )
Longitude 6.77330 W ( 6° 46.4' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 7.33 m
Maximum Sensor or Sampling Depth 50.43 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
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 -
 

Parameters

BODC CODERankUnitsTitle
PRESPR011DecibarsPressure (spatial coordinate) exerted by the water body by profiling pressure sensor and correction to read zero at sea level
PSALPR011DimensionlessPractical salinity of the water body by conductivity cell 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

Open 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.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."


Narrative Documents

Bissett-Bermann 9040 Conductivity Temperature and Depth

The basic configuration of the B-B 9040 CTD incorporates pressure, temperature and conductivity sensors which could be logged digitally. This system also made it possible to derive other parameters, such as salinity, depth and sound velocity.

The instrument was versatile and it was possible to attach a dissolved oxygen sensor or to change the CTD housing, allowing it to obtain data from deeper layers in the water column. The accuracy for salinity is ±0.02 ppt , and ±0.02°C for temperature.

This instrument was also known as the Plessey 9040.

RRS Challenger Cruise 14/87 CTD Data Documentation

Introduction

Documentation for the CTD data collected on RRS Challenger Cruise 14/87 (April-May 1987) by the Scottish Marine Biological Association, Oban, Argyll, Scotland, UK, under the direction of D. J. Ellett.

Instrumentation

The instrument used was a Bissett Berman 9040 CTD system and the data were logged on a Hewlett Packard 9820 and stored in an integer format. Instrument lowering and raising speeds were between 0.5 m/s and 1 m/s. An acoustic pinger was placed above the CTD to give an accurate depth measurement, this could then be used to check the CTD pressure calibration. An NIO bottle with reversing thermometers was placed above the pinger, within 2m of the CTD system. A bottle sample was taken at the bottom of the cast providing the temperature and salinity are uniform at that point. If large temperature or salinity gradients were present then the bottle sample was triggered at a suitable site on the upcast. A surface salinity sample was also taken at the start of the dip.

Calibration

The CTD was not calibrated in the laboratory. The manufacturer's calibration was used and water samples taken to check the calibration and apply corrections where necessary.

Temperature

The manufacturer's calibration was used to convert the raw data to to physical units using the equation below:

Temperature (°C) = (106/Pt -2238.68/55.84)

where Pt is the temperature period in microseconds

These values were then plotted against the water bottle (i.e. reversing thermometer) temperatures and a regression line fitted to the data such that:

Temperature(WB) = m x Temperature(CTD) + c

Then the regression coefficients (m and c) were applied to correct the CTD temperature data - these are given in the table below.

Conductivity

The manufacturer's calibration was used to convert the raw data to to physical units using the equation below:

Conductivity (mmho/cm) = (106/Pc - 4995)/58.12 + 10

where Pc is the conductivity period in microseconds

The water bottle salinities and corrected CTD temperatures were used to calculate the water bottle conductivity values. These values were then plotted against the CTD conductivities and a regression line fitted to the data such that:

Conductivity(WB) = m x Conductivity(CTD) + c

Then the regression coefficients were applied to correct the CTD conductivity data - these are given in the table below.

Pressure

The depths from the acoustic pinger were noted where the bottle samples were taken and then used to check the calibration of the pressure sensor - unless calibration values were available from the reversing thermometers. The equation below was used to convert the pressure period to physical units.

Pressure = (106/Pd - 9712)/0.26267

where Pd is the pressure period in microseconds

A regression fit was carried out using the calibration values and the slope and intercept determined. The pressure values could then be corrected using:

Pressure (CORR) = m x Pressure(CTD) + c

The fit of the CTD data to the water bottle calibration data is given in the table below:

Variable Slope (m) Intercept (c)
Temperature (°C) 1.0005730 0.026395
Conductivity (mmho/cm) 1.0041988 -0.092385
Pressure (dbar) 0.9992293 15.648184

Data Processing

Obvious wild points were edited out of the calibration file and the calibration programs run to obtain values for the slopes and intercepts for temperature, pressure and conductivity. These were then applied to the uncalibrated data. Conductivities were converted to conductivity ratios and then converted to salinities using UNESCO recommended routines and sigma-t was calculated. The data values were then sieved to ensure a minimum separation between pressure values of 1 dbar. The data were then visually inspected and major spikes flagged.

References

Fofonoff, N.P. and Millard Jr., R.C. (1983).
Algorithms for the computation of fundamental properties of sea water. UNESCO Technical Paper on Marine Science 44.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name CH14
Departure Date 1987-04-24
Arrival Date 1987-05-07
Principal Scientist(s)David J Ellett (Scottish Marine Biological Association)
Ship RRS Challenger

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameDML Line P Station P4
CategoryOffshore location
Latitude56° 5.00' N
Longitude6° 47.00' W
Water depth below MSL50.0 m

DML Station P4

Station P4 is one of seven fixed CTD stations between Skerryvore and Islay (Scotland). The station was established by scientists at Dunstaffnage Marine Laboratory (DML).

Related Fixed Station activities are detailed in Appendix 1

Fixed Station Information

Station NameDML Line P
CategoryOffshore route/traverse

DML Line P

Line P is a survey section between Skerryvore and Islay (off the west coast of Scotland). The line comprises seven fixed CTD stations, which were established as part of routine monitoring work on the Scottish continental shelf by Dunstaffnage Marine Laboratory (DML). The line was occupied between the mid 1980s and mid 1990s.

Map of standard DML Line P CTD Stations

BODC image

Map produced using the GEBCO Digital Atlas.

The white triangles indicate the nominal positions of each standard station on DML Line P.

Nominal station details

DML Line P: Skerryvore (Scotland) - Islay (Scotland)

Station Nominal latitude Nominal longitude Approx.
depth (m)
Comment
P1 56° 17.0' N 07° 05.0' W 65 Skerryvore
P2 56° 13.0' N 06° 59.0' W 75  
P3 56° 09.0' N 06° 53.0' W 55  
P4 56° 05.0' N 06° 47.0' W 50  
P5 56° 01.0' N 06° 41.0' W 55  
P6 55° 57.0' N 06° 35.0' W 50  
P7 55° 53.0' N 06° 29.0' W 25 Eil'n nam Meann (Islay)

In addition to Line B, there are other DML repeated survey transects which converge at Islay. These are Line B, Line C, and Line D.

Related Fixed Station activities are detailed in Appendix 2


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
B nominal value
Q value below limit of quantification

Appendix 1: DML Line P Station P4

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
254792CTD or STD cast1985-05-14 11:27:0056.0833 N, 6.7816 WRRS Challenger CH4/85
255678CTD or STD cast1985-12-13 23:12:0056.0833 N, 6.7833 WRRS Frederick Russell FR13/85
343899CTD or STD cast1987-01-14 01:53:0056.085 N, 6.7867 WRRS Challenger CH9
251849CTD or STD cast1987-11-29 01:42:0056.0833 N, 6.7816 WRRS Challenger CH22
266234CTD or STD cast1989-05-08 21:44:0056.0833 N, 6.7833 WRV Lough Foyle LF1/89
318454CTD or STD cast1989-08-09 15:34:0056.0833 N, 6.7867 WRV Lough Foyle LF2/89
386734CTD or STD cast1992-10-01 01:36:0056.0833 N, 6.785 WRRS Challenger CH97
387123CTD or STD cast1992-10-03 18:37:0056.0817 N, 6.7917 WRRS Challenger CH97
389676CTD or STD cast1994-05-09 18:44:0056.0833 N, 6.7833 WRRS Challenger CH112

Appendix 2: DML Line P

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
254767CTD or STD cast1985-05-14 08:34:0056.285 N, 7.0866 WRRS Challenger CH4/85
254779CTD or STD cast1985-05-14 09:30:0056.2166 N, 6.9833 WRRS Challenger CH4/85
254780CTD or STD cast1985-05-14 10:26:0056.15 N, 6.8866 WRRS Challenger CH4/85
254792CTD or STD cast1985-05-14 11:27:0056.0833 N, 6.7816 WRRS Challenger CH4/85
254811CTD or STD cast1985-05-14 12:24:0056.0183 N, 6.6816 WRRS Challenger CH4/85
254823CTD or STD cast1985-05-14 13:22:0055.95 N, 6.5833 WRRS Challenger CH4/85
255642CTD or STD cast1985-12-13 20:20:0055.8833 N, 6.4833 WRRS Frederick Russell FR13/85
255654CTD or STD cast1985-12-13 21:15:0055.95 N, 6.5833 WRRS Frederick Russell FR13/85
255666CTD or STD cast1985-12-13 22:14:0056.0166 N, 6.6833 WRRS Frederick Russell FR13/85
255678CTD or STD cast1985-12-13 23:12:0056.0833 N, 6.7833 WRRS Frederick Russell FR13/85
255691CTD or STD cast1985-12-14 00:15:0056.1516 N, 6.8866 WRRS Frederick Russell FR13/85
255709CTD or STD cast1985-12-14 01:07:0056.2166 N, 6.9833 WRRS Frederick Russell FR13/85
255710CTD or STD cast1985-12-14 01:58:0056.2833 N, 7.0833 WRRS Frederick Russell FR13/85
343875CTD or STD cast1987-01-14 00:06:0055.9483 N, 6.5833 WRRS Challenger CH9
343887CTD or STD cast1987-01-14 01:00:0056.0183 N, 6.6867 WRRS Challenger CH9
343899CTD or STD cast1987-01-14 01:53:0056.085 N, 6.7867 WRRS Challenger CH9
343906CTD or STD cast1987-01-14 02:45:0056.1483 N, 6.885 WRRS Challenger CH9
343918CTD or STD cast1987-01-14 03:42:0056.215 N, 6.9817 WRRS Challenger CH9
343931CTD or STD cast1987-01-14 04:40:0056.2833 N, 7.0833 WRRS Challenger CH9
251118CTD or STD cast1987-05-05 02:46:0056.2833 N, 7.0833 WRRS Challenger CH14
251143CTD or STD cast1987-05-05 04:28:0056.1466 N, 6.8816 WRRS Challenger CH14
251167CTD or STD cast1987-05-05 06:05:0056.0166 N, 6.6716 WRRS Challenger CH14
251179CTD or STD cast1987-05-05 06:56:0055.9516 N, 6.5783 WRRS Challenger CH14
251180CTD or STD cast1987-05-05 07:47:0055.8833 N, 6.4833 WRRS Challenger CH14
251813CTD or STD cast1987-11-28 23:04:0055.8833 N, 6.4816 WRRS Challenger CH22
251825CTD or STD cast1987-11-28 23:57:0055.95 N, 6.5816 WRRS Challenger CH22
251837CTD or STD cast1987-11-29 00:49:0056.0166 N, 6.68 WRRS Challenger CH22
251849CTD or STD cast1987-11-29 01:42:0056.0833 N, 6.7816 WRRS Challenger CH22
251850CTD or STD cast1987-11-29 02:33:0056.15 N, 6.8833 WRRS Challenger CH22
251862CTD or STD cast1987-11-29 03:22:0056.2166 N, 6.985 WRRS Challenger CH22
251874CTD or STD cast1987-11-29 04:14:0056.2816 N, 7.085 WRRS Challenger CH22
266209CTD or STD cast1989-05-08 19:30:0055.8833 N, 6.4833 WRV Lough Foyle LF1/89
266210CTD or STD cast1989-05-08 20:10:0055.95 N, 6.5833 WRV Lough Foyle LF1/89
266222CTD or STD cast1989-05-08 20:54:0056.0166 N, 6.6833 WRV Lough Foyle LF1/89
266234CTD or STD cast1989-05-08 21:44:0056.0833 N, 6.7833 WRV Lough Foyle LF1/89
266246CTD or STD cast1989-05-08 22:39:0056.15 N, 6.8833 WRV Lough Foyle LF1/89
266258CTD or STD cast1989-05-08 23:38:0056.2166 N, 6.9833 WRV Lough Foyle LF1/89
266271CTD or STD cast1989-05-09 00:32:0056.2833 N, 7.0833 WRV Lough Foyle LF1/89
318429CTD or STD cast1989-08-09 13:36:0055.8833 N, 6.4833 WRV Lough Foyle LF2/89
318430CTD or STD cast1989-08-09 14:09:0055.95 N, 6.5833 WRV Lough Foyle LF2/89
318442CTD or STD cast1989-08-09 14:50:0056.0167 N, 6.6833 WRV Lough Foyle LF2/89
318454CTD or STD cast1989-08-09 15:34:0056.0833 N, 6.7867 WRV Lough Foyle LF2/89
318466CTD or STD cast1989-08-09 16:19:0056.15 N, 6.8833 WRV Lough Foyle LF2/89
318478CTD or STD cast1989-08-09 17:12:0056.2183 N, 6.985 WRV Lough Foyle LF2/89
318491CTD or STD cast1989-08-09 17:51:0056.2833 N, 7.0833 WRV Lough Foyle LF2/89
386709CTD or STD cast1992-09-30 23:07:0056.28 N, 7.0833 WRRS Challenger CH97
386710CTD or STD cast1992-09-30 23:57:0056.2167 N, 6.9867 WRRS Challenger CH97
386722CTD or STD cast1992-10-01 00:50:0056.15 N, 6.8833 WRRS Challenger CH97
386734CTD or STD cast1992-10-01 01:36:0056.0833 N, 6.785 WRRS Challenger CH97
386746CTD or STD cast1992-10-01 02:22:0056.015 N, 6.6833 WRRS Challenger CH97
386758CTD or STD cast1992-10-01 03:10:0055.9517 N, 6.585 WRRS Challenger CH97
386771CTD or STD cast1992-10-01 03:57:0055.89 N, 6.4833 WRRS Challenger CH97
387080CTD or STD cast1992-10-03 16:03:0056.2783 N, 7.095 WRRS Challenger CH97
387092CTD or STD cast1992-10-03 16:50:0056.2183 N, 6.9833 WRRS Challenger CH97
387111CTD or STD cast1992-10-03 17:43:0056.1517 N, 6.8817 WRRS Challenger CH97
387123CTD or STD cast1992-10-03 18:37:0056.0817 N, 6.7917 WRRS Challenger CH97
387135CTD or STD cast1992-10-03 19:25:0056.0183 N, 6.6833 WRRS Challenger CH97
387147CTD or STD cast1992-10-03 20:15:0055.95 N, 6.58 WRRS Challenger CH97
387159CTD or STD cast1992-10-03 21:04:0055.8867 N, 6.4817 WRRS Challenger CH97
389640CTD or STD cast1994-05-09 16:30:0056.2833 N, 7.0833 WRRS Challenger CH112
389652CTD or STD cast1994-05-09 17:17:0056.2167 N, 6.9848 WRRS Challenger CH112
389664CTD or STD cast1994-05-09 18:03:0056.15 N, 6.8833 WRRS Challenger CH112
389676CTD or STD cast1994-05-09 18:44:0056.0833 N, 6.7833 WRRS Challenger CH112
389688CTD or STD cast1994-05-09 19:27:0056.0167 N, 6.6833 WRRS Challenger CH112
389707CTD or STD cast1994-05-09 20:12:0055.95 N, 6.5833 WRRS Challenger CH112
389719CTD or STD cast1994-05-09 20:59:0055.8833 N, 6.4833 WRRS Challenger CH112