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Metadata Report for BODC Series Reference Number 258001


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 C1084/095
BODC Series Reference 258001
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1984-12-04 10:38
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 55.64160 N ( 55° 38.5' N )
Longitude 5.94830 W ( 5° 56.9' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 4.95 m
Maximum Sensor or Sampling Depth 110.56 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 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

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 10/84 CTD Data Documentation

Introduction

Documentation for the CTD data collected on RRS Challenger Cruise 10/84 (November-December 1984) by the Scottish Marine Biological Association, Oban, Argyll, Scotland, UK, under the direction of D. J. Ellett.

Caution

Inspection of the pressure records from this cruise reveals several negative values (by up to 1.7db) at the start of Cast No. 030 (BODC Series Ref. 257292) while the temperature and salinity values appear reasonable), thus casting some doubt on the accuracy of the pressure calibration. These data values have been flagged.

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 0.5m/s and 1m/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 physical units using the equation below:

Temperature (°C) = (10**6/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 physical units using the equation below:

Conductivity (mmho/cm) = (10**6/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 = (10**6/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) 1.00213 0.0492
Conductivity (mmho/cm) 1.00486 -0.1091
Pressure (dbar) 1.00197 7.66

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 CH10/84
Departure Date 1984-11-16
Arrival Date 1984-12-06
Principal Scientist(s)Anton Edwards (Scottish Marine Biological Association)
Ship RRS Challenger

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameDML Line B
CategoryOffshore route/traverse

DML Line B

Line B is a survey section between Islay and Kintyre on the west coast of Scotland. The line comprises five 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 during the 1980s.

Map of standard DML Line B CTD Stations

BODC image

Map produced using the GEBCO Digital Atlas.

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

Nominal station details

DML Line B: Glenacardoch Point (Kintyre, Scotland) - Ardmore Island (Islay, Scotland)

Station Nominal latitude Nominal longitude Approx.
depth (m)
Comment
1B 55° 35.0' N 05° 45.0' W 20 Glenacardoch Point
2B 55° 36.0' N 05° 49.0' W 50  
3B 55° 37.0' N 05° 53.0' W 105  
4B 55° 38.0' N 05° 57.0' W 110  
5B 55° 39.0' N 06° 01.0' W 20 Ardmore Island

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

Related Fixed Station activities are detailed in Appendix 1

Fixed Station Information

Station NameDML Line B Station 4B
CategoryOffshore location
Latitude55° 38.00' N
Longitude5° 57.00' W
Water depth below MSL110.0 m

DML Station 4B

Station 4B is one of five fixed CTD stations between Islay and Kintyre on the west coast of Scotland, established by scientists at Dunstaffnage Marine Laboratory (DML).

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
Q value below limit of quantification

Appendix 1: DML Line B

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
193231CTD or STD cast1983-05-22 16:17:0055.6 N, 5.7516 WRRS Challenger CH7A/83
193243CTD or STD cast1983-05-22 16:42:0055.6 N, 5.8166 WRRS Challenger CH7A/83
193255CTD or STD cast1983-05-22 17:10:0055.6183 N, 5.8866 WRRS Challenger CH7A/83
193267CTD or STD cast1983-05-22 17:52:0055.6333 N, 5.95 WRRS Challenger CH7A/83
193279CTD or STD cast1983-05-22 18:22:0055.65 N, 6.015 WRRS Challenger CH7A/83
96485CTD or STD cast1983-08-11 06:56:0055.6416 N, 6.015 WRRS Challenger CH11/83
96497CTD or STD cast1983-08-11 07:59:0055.6416 N, 5.95 WRRS Challenger CH11/83
193833CTD or STD cast1983-08-11 08:19:0055.6166 N, 5.8833 WRRS Challenger CH11/83
96504CTD or STD cast1983-08-11 09:55:0055.6066 N, 5.815 WRRS Challenger CH11/83
96516CTD or STD cast1983-08-11 16:31:0055.58 N, 5.7483 WRRS Challenger CH11/83
97648CTD or STD cast1984-06-25 06:01:0055.5833 N, 5.75 WRRS Challenger CH2/84
97661CTD or STD cast1984-06-25 06:45:0055.6083 N, 5.8833 WRRS Challenger CH2/84
97673CTD or STD cast1984-06-25 07:39:0055.6166 N, 5.8833 WRRS Challenger CH2/84
97685CTD or STD cast1984-06-25 08:51:0055.6416 N, 5.95 WRRS Challenger CH2/84
97697CTD or STD cast1984-06-25 09:31:0055.65 N, 6.0166 WRRS Challenger CH2/84
258013CTD or STD cast1984-12-04 11:22:0055.6166 N, 5.8833 WRRS Challenger CH10/84
258025CTD or STD cast1984-12-04 12:00:0055.6083 N, 5.815 WRRS Challenger CH10/84
258037CTD or STD cast1984-12-04 12:49:0055.5833 N, 5.75 WRRS Challenger CH10/84
258781CTD or STD cast1985-01-30 07:56:0055.65 N, 6.0166 WRRS Challenger CH1/85
258793CTD or STD cast1985-01-30 08:28:0055.6416 N, 5.9483 WRRS Challenger CH1/85
258800CTD or STD cast1985-01-30 09:04:0055.6166 N, 5.885 WRRS Challenger CH1/85
258812CTD or STD cast1985-01-30 09:40:0055.6083 N, 5.8166 WRRS Challenger CH1/85
258824CTD or STD cast1985-01-30 13:30:0055.5833 N, 5.75 WRRS Challenger CH1/85
253008CTD or STD cast1985-05-03 03:50:0055.5833 N, 5.75 WRRS Challenger CH4/85
253021CTD or STD cast1985-05-03 04:27:0055.6066 N, 5.8166 WRRS Challenger CH4/85
253033CTD or STD cast1985-05-03 05:03:0055.6166 N, 5.8833 WRRS Challenger CH4/85
253045CTD or STD cast1985-05-03 05:50:0055.6416 N, 5.95 WRRS Challenger CH4/85
253057CTD or STD cast1985-05-03 06:26:0055.6533 N, 6.0166 WRRS Challenger CH4/85
254859CTD or STD cast1985-05-14 21:45:0055.6166 N, 5.8816 WRRS Challenger CH4/85
260773CTD or STD cast1985-08-17 07:33:0055.5833 N, 5.7516 WRRS Challenger CH8/85
260785CTD or STD cast1985-08-17 08:11:0055.6066 N, 5.8183 WRRS Challenger CH8/85
260797CTD or STD cast1985-08-17 08:44:0055.6166 N, 5.8866 WRRS Challenger CH8/85
260804CTD or STD cast1985-08-17 09:33:0055.6416 N, 5.9516 WRRS Challenger CH8/85
260816CTD or STD cast1985-08-17 10:15:0055.6483 N, 6.0166 WRRS Challenger CH8/85
255421CTD or STD cast1985-12-10 21:37:0055.5866 N, 5.7583 WRRS Frederick Russell FR13/85
255433CTD or STD cast1985-12-10 22:14:0055.5916 N, 5.8083 WRRS Frederick Russell FR13/85
255445CTD or STD cast1985-12-10 22:53:0055.6166 N, 5.8866 WRRS Frederick Russell FR13/85
255457CTD or STD cast1985-12-10 23:50:0055.6416 N, 5.9566 WRRS Frederick Russell FR13/85
255469CTD or STD cast1985-12-11 00:27:0055.6516 N, 6.0166 WRRS Frederick Russell FR13/85
251192CTD or STD cast1987-05-05 11:12:0055.6516 N, 6.015 WRRS Challenger CH14
251211CTD or STD cast1987-05-05 11:45:0055.6416 N, 5.95 WRRS Challenger CH14
251223CTD or STD cast1987-05-05 12:28:0055.6166 N, 5.8833 WRRS Challenger CH14
251235CTD or STD cast1987-05-05 13:08:0055.61 N, 5.815 WRRS Challenger CH14
251247CTD or STD cast1987-05-05 13:42:0055.585 N, 5.7483 WRRS Challenger CH14
266418CTD or STD cast1989-05-09 20:50:0055.65 N, 6.0166 WRV Lough Foyle LF1/89
266431CTD or STD cast1989-05-09 21:19:0055.6333 N, 5.95 WRV Lough Foyle LF1/89
266443CTD or STD cast1989-05-09 21:45:0055.6166 N, 5.8833 WRV Lough Foyle LF1/89
266455CTD or STD cast1989-05-09 22:11:0055.6 N, 5.8166 WRV Lough Foyle LF1/89
266467CTD or STD cast1989-05-09 22:40:0055.5833 N, 5.75 WRV Lough Foyle LF1/89
318325CTD or STD cast1989-08-09 04:47:0055.585 N, 5.75 WRV Lough Foyle LF2/89
318337CTD or STD cast1989-08-09 05:05:0055.6 N, 5.8167 WRV Lough Foyle LF2/89
318349CTD or STD cast1989-08-09 05:28:0055.6183 N, 5.8833 WRV Lough Foyle LF2/89
318350CTD or STD cast1989-08-09 05:54:0055.635 N, 5.95 WRV Lough Foyle LF2/89
318362CTD or STD cast1989-08-09 06:20:0055.6517 N, 6.0167 WRV Lough Foyle LF2/89
384322CTD or STD cast1991-11-29 00:19:0055.6317 N, 5.9467 WRRS Challenger CH86B
384334CTD or STD cast1991-11-29 00:58:0055.615 N, 5.8833 WRRS Challenger CH86B
384346CTD or STD cast1991-11-29 01:40:0055.6017 N, 5.8217 WRRS Challenger CH86B

Appendix 2: DML Line B Station 4B

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
193267CTD or STD cast1983-05-22 17:52:0055.6333 N, 5.95 WRRS Challenger CH7A/83
96497CTD or STD cast1983-08-11 07:59:0055.6416 N, 5.95 WRRS Challenger CH11/83
97685CTD or STD cast1984-06-25 08:51:0055.6416 N, 5.95 WRRS Challenger CH2/84
258793CTD or STD cast1985-01-30 08:28:0055.6416 N, 5.9483 WRRS Challenger CH1/85
253045CTD or STD cast1985-05-03 05:50:0055.6416 N, 5.95 WRRS Challenger CH4/85
260804CTD or STD cast1985-08-17 09:33:0055.6416 N, 5.9516 WRRS Challenger CH8/85
255457CTD or STD cast1985-12-10 23:50:0055.6416 N, 5.9566 WRRS Frederick Russell FR13/85
251211CTD or STD cast1987-05-05 11:45:0055.6416 N, 5.95 WRRS Challenger CH14
266431CTD or STD cast1989-05-09 21:19:0055.6333 N, 5.95 WRV Lough Foyle LF1/89
318350CTD or STD cast1989-08-09 05:54:0055.635 N, 5.95 WRV Lough Foyle LF2/89
384322CTD or STD cast1991-11-29 00:19:0055.6317 N, 5.9467 WRRS Challenger CH86B