Metadata Report for BODC Series Reference Number 510976


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Sea-Bird SBE 25 Sealogger CTD  CTD; water temperature sensor; salinity sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator -
Originating Organization Fisheries Research Services Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory)
Processing Status banked
Project(s) -
 

Data Identifiers

Originator's Identifier CU07/98/0116
BODC Series Reference 510976
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1998-05-05 14:09
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars
 

Spatial Co-ordinates

Latitude 58.88250 N ( 58° 52.9' N )
Longitude 3.15070 W ( 3° 9.0' W )
Positional Uncertainty 0.5 to 1.0 n.miles
Minimum Sensor Depth 0.99 m
Maximum Sensor Depth 32.69 m
Minimum Sensor Height 3.31 m
Maximum Sensor Height 35.01 m
Sea Floor Depth 36.0 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 Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
CNDCZZ01 1 Siemens per metre Cond Electrical conductivity of the water body
PRESPR01 1 Decibars Pres_Z Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level
PSALPR01 1 Dimensionless P_sal Practical salinity of the water body by conductivity cell and computation using UNESCO 1983 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

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

Sea-Bird SBE 25 SEALOGGER CTD

The SBE 25 SEALOGGER is a research-quality CTD profiling system used for coastal, estuarine and, can also be a practical option, for deep-water work. It is easily configured in the field for a wide range of auxiliary sensors. The SEALOGGER is self-powered, requires no conductive cable, and is designed for use up to 6800 meters (10,000 psia). It uses the SBE3F temperature and SBE4 conductivity sensors as well as having an external strain gauge pressure sensor. It provides pump-controlled T-C ducted flow, samples at 8 Hz, records internally and provides simultaneous real-time data via its built-in RS-232 interface.

The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by aluminium housing for depths up to 6800 m.

Specifications

Parameter SBE 25
Temperature

Range: -5 to +35 °C

Accuracy: 0.002 °C

Resolution: 0.0003 °C

Conductivity

Range: 0 to 7 S m -1 (0 to 70 mmho cm -1 )

Accuracy: 0.0003 S m -1

Resolution: 0.00004 S m -1

Strain gauge pressure sensor

Range: 0 to 20, 100, 350, 600, 1000, 2000, 3500, 7000 metres (expressed in metres of deployment depth capability)

Accuracy: 0.1% of full scale range

Resolution: 0.015% of full scale range

Options and accessories

Additional sensors can be attached to the CTD, including:

The SBE 5T titanium pump can be used in place of SBE 5P pump. Further details can be found in the manufacturer's SBE 25 instrument specification.

RV Clupea 07/98 CTD Data Documentation

Introduction

Documentation for data collected on R.V. Clupea cruise 7/98 (4th May - 10th May 1998) by the Fisheries Research Services of the Scottish Marine Office, Aberdeen UK.

The cruise objectives were:

  1. To conduct a hydrographic and biological survey of the Orkney area including Scapa Flow.

  2. To deploy tide gauges in three locations in Scapa Flow.

  3. To collect sediment samples by Day Grab.

Instrumentation and Protocols

The temperature and salinity data were collected using a SEALOGGER instrument and the data have been calibrated using bottle samples and thermometer readings to produce the following equations:

T(cal) = T(obs)

C(cal) = 1.0018C(obs) - 0.001

For any further information contact:

George Slesser
Marine Laboratory Aberdeen
PO Box 101
Victoria Road
Aberdeen AB11 9DB
Slesser@marlab.ac.uk

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


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name 0798C
Departure Date 1998-05-04
Arrival Date 1998-05-10
Principal Scientist(s)Marie Kelly (Fisheries Research Services Aberdeen Marine Laboratory)
Ship FRV Clupea

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

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