Metadata Report for BODC Series Reference Number 713940

Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
SeaDataNet Quality Flags

Metadata Summary

Data Description

Data Category

CTD or STD cast

Instrument Type

Name	Categories
Sea-Bird SBE 19 SEACAT CTD	CTD; water temperature sensor; salinity sensor

Instrument Mounting

research vessel

Originating Country

United Kingdom

Originator

Ms Sarah Hughes

Originating Organization

Fisheries Research Services Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory)

Processing Status

banked

Online delivery of data

Download available - Ocean Data View (ODV) format

Project(s)

Data Identifiers

Originator's Identifier	SC17/05/485
BODC Series Reference	713940

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm)	2005-12-02 12:19
End Time (yyyy-mm-dd hh:mm)	-
Nominal Cycle Interval	1.0 decibars

Spatial Co-ordinates

Latitude	56.18567 N ( 56° 11.1' N )
Longitude	7.39233 W ( 7° 23.5' W )
Positional Uncertainty	0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth	2.97 m
Maximum Sensor or Sampling Depth	98.07 m
Minimum Sensor or Sampling Height	7.93 m
Maximum Sensor or Sampling Height	103.03 m
Sea Floor Depth	106.0 m
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	Instantaneous - Depth measured below water line or instantaneous water body surface

Parameters

BODC CODE	Rank	Units	Title
CNDCST01	1	Siemens per metre	Electrical conductivity of the water body by CTD
PRESPR01	1	Decibars	Pressure (spatial coordinate) exerted by the water body by profiling pressure sensor and correction to read zero at sea level
PSALST01	1	Dimensionless	Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm
TEMPST01	1	Degrees Celsius	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

Public domain 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.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

Narrative Documents

Instrument Description

CTD Unit and Auxiliary Sensors

A Sea-Bird Electronics SBE19 SEACAT CTD unit was used. The CTD unit included the following sensors.

Sensor	Manufacturer	Serial number	Calibration date
Pressure	Sea-Bird	1761	2004-01-22
Temperature	Sea-Bird	1761	2004-01-22
Conductivity	Sea-Bird	1761	2004-01-22

Calibrations

Independent water samples were used to calibrate the CTD conductivity data. The following calibration values were supplied to BODC, who applied them to the data as part of the transfer process.

Parameter	Value of m (y=mx+c)	Value of c (y=mx+c)	Equation
Conductivity	1.016435	-0.664615	C(cal) = 1.016435C(obs) -0.664615

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 19plus model in 2001. An updated version of this instrument is the SBE 19plus 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.

Specifications

Parameter	SBE 19	SBE 19plus
Temperature	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*
Conductivity	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

Parameter

SBE 19

SBE 19plus

Temperature

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*

Conductivity

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:

high accuracy Paroscientific Digiquartz pressure sensor (depth range 0 to 20, 60, 130, 200, 270, 680, 1400, 2000, 4200, 7000 or 10500 m; accuracy 0.02% of full scale; resolution 0.0025% of full scale)
Dissolved Oxygen (SBE 43 DO Sensor)
pH* (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor)
fluorescence
radiance (PAR)
light transmission
optical backscatter (turbidity)

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 19plus V2 instrument specification or theSBE 19 andSBE 19 plus user guides.

BODC Processing

Data were received by BODC in one ASCII format file that was subsequently split into seven separate files, one for each CTD profile. The series were reformatted to the internal QXF format using BODC transfer function 340. The following table details the mapping of variables to BODC parameter codes.

Original parameter name	Original Units	Description	BODC Parameter Code	BODC Units	Comments
Pressure	Decibars	Pressure exerted by the water column	PRESPR01	Decibars
Temperature	°C	Temperature of the water column	TEMPST01	°C
Conductivity	mS cm^-1	Electrical conductivity of the water column	CNDCST01	S m^-1	Conversion by transfer (mS cm^-1 x 0.1)
Salinity	Dimensionless	Practical salinity of the water column by CTD and computation using UNESCO 1983 algorithm	PSALST01	Dimensionless

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'. Flags from the originator marking suspect data were retained during transfer and flagged 'L'.

Originator's Data Processing

The raw CTD data files were processed through the SeaBird Electronics SeaSoft data processing software following standard procedures. The originators used in-house interactive visual display editing software to edit out individual spikes in the primary temperature and conductivity channels. An ASCII file was generated for each CTD cast and all files from a cruise were concatenated into one ASCII file which was submitted to BODC.

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name	1705S
Departure Date	2005-11-16
Arrival Date	2005-12-07
Principal Scientist(s)	Alexander P Robb (Fisheries Research Services Aberdeen Marine Laboratory)
Ship	FRV Scotia

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

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