Metadata Report for BODC Series Reference Number 934817


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Valeport CTD 600  CTD; water temperature sensor; salinity sensor
Instrument Mounting vessel at fixed position
Originating Country France
Originator Dr Valerie Quiniou-Ramus
Originating Organization TotalFinaElf (now Total S.A.)
Processing Status banked
Project(s) SIMORC
 

Data Identifiers

Originator's Identifier 5573_3
BODC Series Reference 934817
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2001-01-11 20:39
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 0.5 seconds
 

Spatial Co-ordinates

Latitude 3.89425 N ( 3° 53.7' N )
Longitude 7.90347 E ( 7° 54.2' E )
Positional Uncertainty 0.01 to 0.05 n.miles
Minimum Sensor Depth 0.0 m
Maximum Sensor Depth 108.07 m
Minimum Sensor Height 1.63 m
Maximum Sensor Height 109.7 m
Sea Floor Depth 109.7 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 Unspecified -
 

Parameters

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
SVELCT01 1 Metres per second CTD_Sound_Vel Sound velocity in the water body by CTD and computation from temperature and salinity by unspecified 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 Access Policy

SIMORC data access conditions

The data collated and held at BODC on behalf of the SIMORC project are restricted. However, the data will be available to download from the Official SIMORC Website, as part of the project protocol. The data set will initially include data from the oil companies TOTAL, Shell and BP.


Narrative Documents

Instrument description

Valeport 600 MKIII CTD

The Model 600 MKIII measures Conductivity, Temperature and Pressure parameters and has both time and depth increment based sampling. From these measurements Salinity, Density and Speed of Sound are calculated and displayed or recorded.

Specifications

Temperature

Thermistor range: -5 to 35 °C ; precision: +/- 0.1 °C

Conductivity

Inductive coils range: 0.1 to 60 mS.cm -1 ; precision: +/- 0.05 mS.cm -1

Pressure

Strain gauge range: 50,100, 500,1000 or 2000 dBar; precision: +/-0.5%

Manufacturer specifications can be found here

Valeport CTD 600

Background

The Valeport CTD 600 is designed for Continental Shelf operation and permits the accurate measurement of seawater Conductivity and Temperature against a Depth profile. The results obtained are applicable to many fields of scientific research. The meter is particularly suited to the obtaining of Temperature and Salinity profiles for the computation of the Speed of Sound through water, as required for the calibration of survey echo sounders and acoustic navigation systems.

More information may be found:

Click here for an Oceanscan instrument description

Click here for a pdf stored by BODC.

Parameters

Parameter Sensor Type Operating Range Accuracy Display Resolution Response Time
Conductivity Dual inductive coils 0 - 60 mmho cm -1 Better than 0.2 mmho cm -1 0.01 mmho cm -1 -
Temperature Linearised Thermistor -5 to +40 °C Better than 0.2 °C 0.01 °C < 3 secs to 98%
Pressure Strain gauge pressure transducer 0 to 10, or 0 to 20 bar standard, (100 or 200 m)

Optional, 0 to 50 bar (500 m)

Note, 10 bar fitted in units with 50 m cables

+/- 0.3% of full scale 0.1 m -

BODC CTD Screening

BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.

Header information is inspected for:

Documents are written by BODC highlighting irregularities that cannot be resolved.

Data cycles are inspected using depth series plots of all parameters. These presentations undergo screening to detect infeasible values within the data cycles themselves and inconsistencies when comparing adjacent data sets displaced with respect to depth, position or time.

Values suspected of being of non-oceanographic origin may be tagged with the BODC flag denoting suspect value.

The following types of irregularity, each relying on visual detection in the time series plot, are amongst those that may be flagged as suspect:

If a large percentage of the data is affected by irregularities, deemed abnormal, then instead of flagging the individual suspect values, a caution may be documented.

The following types of inconsistency are detected automatically by software:

Inconsistencies between the characteristics of the data set and those of its neighbours are sought, and where necessary, documented. This covers inconsistencies in the following:

This screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC's making are not introduced.

BODC Processing

The originator provided a Comma Separated Values format file. This series was reformatted to the internal QXF format using BODC transfer function 422. The following table shows how the variables within the file were mapped to the appropriate BODC parameter codes:

Original parameter name Original Units Description BODC Parameter Code BODC Units Comments
Time DD/MM/YYYY HH:MI date and time AADYAA01 + AAFDZZ01 day number and day fraction GMT Conversion by transfer
SoundSpeed m.s -1 Sound velocity SVELCT01 m.s -1  
Depth m   DEPHPR01 m  
Temperature degrees Celsius   TEMPST01 degrees Celsius  
Conductivity S.cm -1   CNDCST01 S.m -1 Conversion (RAW *0.1) by transfer
Pressure decibars   PRESPR01 decibars  
Salinity psu   PSALST01 psu  

Datacycles from the up cast were deleted as only the down cast was transferred.

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'.


Project Information

System of Industry Metocean data for the Offshore and Research Communities (SIMORC)

The EU-funded SIMORC project is a collaborative effort between MARIS (Netherlands), BODC (UK), the International Association of Oil and Gas Producers (OGP) and IOC-IODE to provide a harmonised and quality controlled metocean data set from data collected by oil and gas producers, accessible through the SIMORC protocol.


Data Activity or Cruise Information

Cruise

Cruise Name 2001 3/4
Departure Date 2001-01-11
Arrival Date 2001-01-11
Principal Scientist(s)Unknown (Unknown)
Ship Sea Trident

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameNigeria OML100
CategoryOffshore location
Latitude3° 52.66' N
Longitude7° 55.12' E
Water depth below MSL100.0 m

SIMORC: TOTAL Nigeria OML100 Fixed Station Document

5 CTD casts were taken from 07/01/2001 to 18/07/2002 at this site.

The nominal position of the instrument is 3.877585° N; 7.918625° E with a water depth of 100 m.

CTD casts were done on behalf of TOTAL from Nigeria OML100 fixed station as follows:

Cruise inventory name Instrument Start Date Comments
MV Norwich Service 1/4 VALEPORT USPC 0014 07/01/2001 22:27:00  
MV Norwich Service 2/4 VALEPORT USPC 0014 09/01/2001 22:27:00  
MV Norwich Service 3/4 VALEPORT USPC 0014 11/01/2001 20:39:00  
MV Norwich Service 4/4 VALEPORT USPC 0014 15/01/2001 05:58:00  
  VALEPORT 600 CTD 18/07/2002 18:28:09  

Other Cruises linked to this Fixed Station (with the number of series) - 1/1 (1) 2001 1/4 (1) 2001 2/4 (1) 2001 4/4 (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