Metadata Report for BODC Series Reference Number 963385


Metadata Summary

Data Description

Data Category Hydrography time series at depth
Instrument Type
NameCategories
Sea-Bird SBE 37-SM MicroCAT C-T Sensor  water temperature sensor; salinity sensor
Instrument Mounting subsurface mooring
Originating Country France
Originator Dr Valerie Quiniou-Ramus
Originating Organization Total S.A.
Processing Status QC in progress
Project(s) SIMORC
 

Data Identifiers

Originator's Identifier LOURO_SBE37(69M_BMSL)_TEMP&SAL
BODC Series Reference 963385
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-01-17 12:10
End Time (yyyy-mm-dd hh:mm) 2009-07-25 09:30
Nominal Cycle Interval 600.0 seconds
 

Spatial Co-ordinates

Latitude 7.50400 S ( 7° 30.2' S )
Longitude 11.23420 E ( 11° 14.1' E )
Positional Uncertainty 0.01 to 0.05 n.miles
Minimum Sensor Depth 71.0 m
Maximum Sensor Depth 71.0 m
Minimum Sensor Height 1750.0 m
Maximum Sensor Height 1750.0 m
Sea Floor Depth 1821.0 m
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor Depth Datum Sea floor reference - Depth measured as a height above sea floor but converted into a depth relative to the sea surface according to the same datum as used for sea floor depth (applicable to instrument depths not bathymetric depths)
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
ACYCAA01 1 Dimensionless Record_No Sequence number
PSALPR01 1 Dimensionless P_sal Practical salinity of the water body by conductivity cell and computation using UNESCO 1983 algorithm
TEMPPR01 1 Degrees Celsius Temp Temperature of the water body
 

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

SIMORC Data Quality Report Total Angola Block 32, Louro long mooring salinity data

Narrative

This long mooring forms the observations made in Angola Block 32, Louro.

Data Quality Information

This data quality report refers only to the SBE37 moored CTD on this mooring. The salinity recorded by the SBE37 was fairly noisy throughout the entire timeseries. Spikes were identified as consecutive datacycles differing by more than 0.2 PSU and were flagged suspect.


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

Sea-Bird SBE 37-SM MicroCAT

The SBE 37-SM MicroCAT is a high accuracy conductivity and temperature recorder (pressure optional). Designed for moorings and other long-duration, fixed-site deployments, MicroCATs have non-corroding titanium housings rated for operation to 7000 metres or pressure sensor full scale-range. Communication with the MicroCAT is over an internal, 3-wire, RS-232C link. The MicroCAT's aged and pressure-protected thermistor has a long history of exceptional accuracy and stability (typical drift is less than 0.002° per year). Electrical isolation of the conductivity electronics eliminates any possibility of ground-loop noise.

Specifications

  Temperature
(°C)
Conductivity (S m -1 ) Optional Pressure
Measurement Range -5 to +35 0 to 7 (0 to 70 mS cm -1 ) 0 to full scale range: 20 / 100 / 350 / 1000 / 2000 / 3500 / 7000 metres
Initial accuracy 0.002 0.0003 0.1% of full scale range
Typical Stability 0.0002 per month 0.0003 per month 0.05% of full scale range per year
Resolution 0.0001 0.00001 0.002% of full scale range
Sensor Calibration +1 to +32 0 to 6; physical calibration over range 2.6 to 6 S m -1 , plus zero conductivity (air) Ambient pressure to full scale range in 5 steps
Memory 8 Mbyte non-volatile FLASH memory
Data Storage Converted temperature and conductivity: 6 bytes per sample (3 bytes each)
Time: 4 bytes per sample
Pressure (optional): 5 bytes per sample
Real-Time Clock 32,768 Hz TCXO accurate to ±1 minutes year -1
Standard Internal Batteries Nominal 10.6 Ampere-hour pack consisting of 12 AA lithium batteries. Provides sufficient capacity for more than 630,000 samples for a typical sampling scheme
Housing Titanium pressure case rated at 7000 metres
Weight (without pressure) In water: 2.3 kg
In air: 3.8 kg

Further information can be found via the following link: SBE 37-SM MicroCAT Datasheet

Sea-Bird SBE37-IM MicroCAT

The SBE 37-IM MicroCAT is a high accuracy conductivity and temperature recorder (pressure optional) with a built in Inductive Modem, which provides reliable, low-cost, real-time data transmission. Designed for moorings and other long-duration, fixed-site deployments, MicroCATs have non-corroding titanium housings rated for operation to 7000 metres or pressure sensor full scale-range.

Communication with the MicroCAT is via a Surface Inductive Modem (SIM) to a computer or data logger. Commands and data are transmitted half-duplex between the SIM and the MicroCAT using DPSK (differential-phase-shift-keyed) telemetry. As a safe guard, the MicroCAT simultaneously backs up the data in its non-volatile internal memory as well as transmitting the data via telemetry.

The MicroCAT's aged and pressure-protected thermistor has a long history of exceptional accuracy and stability (typical drift is less than 0.002 °C per year). Electrical isolation of the conductivity electronics eliminates any possibility of ground-loop noise.

Specifications

  Temperature
(°C)
Conductivity (S m -1 ) Optional Pressure
Measurement Range -5 to +35 0 to 7 (0 to 70 mS cm -1 ) 0 to full scale range: 20 / 100 / 350 / 600 / 1000 / 2000 / 3500 / 7000 metres
Initial accuracy 0.002 0.0003 0.1% of full scale range
Typical Stability 0.0002 per month 0.0003 per month 0.05% of full scale range per year
Resolution 0.0001 0.00001 0.002% of full scale range
Sensor Calibration +1 to +32 0 to 6; physical calibration over range 2.6 to 6 S m -1 , plus zero conductivity (air) Ambient pressure to full scale range in 5 steps
Memory 8 Mbyte non-volatile FLASH memory
Data Storage Converted temperature and conductivity: 5 bytes per sample (2.5 bytes each)
Time: 4 bytes per sample
Pressure (optional): 2 bytes per sample
Real-Time Clock 32,768 Hz TCXO accurate to ±1 minutes year -1
Standard Internal Batteries 10.6 Ampere-hour pack consisting of 12 AA lithium batteries. Provides sufficient capacity for more than 200,000 samples for a typical sampling scheme
Housing Titanium pressure case rated at 7000 metres
Weight (without pressure) In water: 2.4 kg
In air: 4.0 kg

Further information can be found via the following link: Sea-Bird SBE37-IM MicroCAT Datasheet

BODC Processing

Data were received by BODC in ASCII format files (Fugro format). They were reformatted to QXF format using BODC transfer function 400. The following table shows how the variables within the files were mapped to the appropriate BODC parameter codes:

Original parameter name Original Units Description BODC Parameter Code BODC Units Comments
Time DD-MON-YY hh:mm:ss Date and time (GMT) AADYAA01 + AAFDZZ01 Day number and day fraction (GMT)  
TEMP degrees Celsius Sea temperature TEMPPR01 degrees Celsius  
SAL PSU Salinity PSALPR01 PSU  

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO.

General Data Screening carried out by BODC

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 which cannot be resolved.

Data cycles are inspected using time or depth series plots of all parameters. Currents are additionally inspected using vector scatter plots and time series plots of North and East velocity components. These presentations undergo intrinsic and extrinsic screening to detect infeasible values within the data cycles themselves and inconsistencies as seen when comparing characteristics of 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 data values will not be altered.

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

If a large percentage of the data is affected by irregularities then a Problem Report will be written rather than flagging the individual suspect values. Problem Reports are also used to highlight irregularities seen in the graphical data presentations.

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

This intrinsic and extrinsic 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 making are not introduced.


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

Data Activity

Start Date (yyyy-mm-dd) 2009-01-17
End Date (yyyy-mm-dd) 2009-07-25
Organization Undertaking ActivityTotal S.A.
Country of OrganizationFrance
Originator's Data Activity IdentifierLouro
Platform Categorysubsurface mooring

SIMORC Total Louro Current Meter and ADCP mooring.

The survey at this site was made up of a single mooring.

This long mooring was deployed in a water depth of 1832 metres. (Nominal position of 7.504°S 11.2342°E):

Meter No. Instrument Depth (m) Instrument Type Total Time Period Comments
9771 41.2 RDI 300kHz ADCP 16-JAN-2009 TO 26-JUL-2009 Upward-looking.
677 42.7 SeaBird SBE37 16-JAN-2009 TO 26-JUL-2009  
11520 446.1 RDI 75kHz ADCP 16-JAN-2009 TO 26-JUL-2009 Upward-looking.
288 446.1 SeaBird SBE39 16-JAN-2009 TO 26-JUL-2009  
12497 696.2 RCM7 16-JAN-2009 TO 26-JUL-2009  
11534 946.2 RCM8 16-JAN-2009 TO 26-JUL-2009  
12474 1196.2 RCM8 16-JAN-2009 TO 26-JUL-2009  
10050 1446.2 RCM8 16-JAN-2009 TO 26-JUL-2009  
11260 1696.2 RCM8 16-JAN-2009 TO 26-JUL-2009  
102 1822 Aanderaa Seaguard 16-JAN-2009 TO 26-JUL-2009 with Aanderaa WLR8

Other Series linked to this Data Activity - 962622 962634 962610 962671 962646 963397 962449 962658 1052455 962450

Cruise

Cruise Name Seabulk Luanda 2009
Departure Date 2009-01-14
Arrival Date 2009-01-19
Principal Scientist(s)
Ship Seabulk Luanda

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameLouro, Angola Block 32
CategoryOffshore location
Latitude7° 30.24' S
Longitude11° 14.05' E
Water depth below MSL1832.0 m

Total - Angola Block 32 - Louro

Latitude Longitude Water depth (m)
7.504°S 11.23417°E 1829

This fixed station is in Block 32, offshore Angola. A mooring was deployed at this site in January 2009 to cover a 12-month period of measurements of currents through the water column. Prior to the mooring deployment, a CTD dip was undertaken to check the actual water depth.

Other Series linked to this Fixed Station for this cruise - 962449 962450 962610 962622 962634 962646 962658 962671 963397 963428 963441

Other Cruises linked to this Fixed Station (with the number of series) - Petrogas1 (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