Metadata Report for BODC Series Reference Number 169138
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
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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
Christian Albrechts University of Kiel Multisonde CTD profiler
A prototype conductivity-temperature-pressure profiler developed in the 1970s by what was then the Institute for Applied Physics of Kiel University. The instrument could measure up to six parameters in total, including sound velocity and light attenuation by means of an auxiliary light sensor. The unit was used by the then Institute for Marine Science, Kiel.
Specifications
Pressure | Temperature | Conductivity | |
---|---|---|---|
Range | 600 or 6000 dbar | -2 to 40 °C | 5 to 55 mmho cm-1 |
Accuracy | ± 0.01% | ± 0.01 °C | ± 10 µmho cm-1 |
WFS Planet Cruise 10/78 CTD Data Documentation
Introduction
Documentation for the CTD data collected on W.F.S. Planet cruise 10/78 15 August 1978 - 14 September 1978, under the direction of G. Siedler, Institut für Meereskunde an der Universität Kiel, Germany.
Instrumentation
The instrument used was a Multisonde CTD, which measured hydrostatic pressure, temperature and electrical conductivity. The initial sampling rate was 16Hz and the lowering rate between 30 to 40 metres/minute.
Calibration
In order to check the calibration during the experiment a Nansen bottle with two protected reversing thermometers was attached to the cable close to the underwater unit. Various combinations of three thermometers were used. Seventeen water samples were collected from about 200m. In addition, 20 samples were taken from lowerings of the Bathysonde CTD on this cruise.
It was assumed that a proper re-calibration could be achieved by determining the offset in temperature and conductivity at this depth level. The pressure offset was found by reading the pressure value at the sea surface. There was no time dependence of these re-calibration terms.
The results of the re-calibration analysis are summarised in the table below. The reversing thermometers were checked after the cruise and some of them had changed. A comparison with other instruments showed that the best temperature calibration was achieved by using an offset of -0.014 °C. The salinity measurements of the Nansen samples were carried out using a Beckman RS7B lab and an Autosal 8400 salinometer. 27 pairs of water samples from one Nansen bottle showed no differences between those two instruments. Conductivity was calculated from the salinity values by an iterative reversal of Fofonoff's (1974) formula using Newton's formula (Peters 1976).
Due to the slow response of the Multisonde thermometers compared to the conductivity sensors, spikes occurred in the salinity profiles. The thermometer time constants were changed in the calculations to optimise the spike reduction. After clipping remaining spikes in salinity, a running mean over about 0.5 dbar was taken. The data were then interpolated to 0.5 dbar increments and again a running mean over 1.5 dbar was calculated.
Re-calibration data for Multisonde CTD
CTD pressure reading at the sea surface (600 dbar) | -4.1 dbar |
CTD pressure reading at 6000 dbar | -22.0 dbar |
Mean difference between reversing thermometer and CTD temperature reading (T(NANSEN)-T(CTD)) | -0.026 °C (±0.012 °C) |
Mean temperature difference between two reversing thermometers in a Nansen bottle | -0.015 °C (±0.009 °C) |
Mean difference between Nansen bottle and CTD conductivity reading (C(NANSEN)-C(CTD)) | +0.0134 10-3 S/cm(±0.0069 10-3 S/cm) |
Time constant of the thermometer | 150 milliseconds |
The final data series are at 0.5 dbar intervals, this information has not been included with the series header details.
References
Peters, H. 1978.
A compilation of CTD and profiling current meter data from GATE 1974, FS Meteor and WFS Planet. 'Meteor' Forschungsergebnisse A No.20 p49-80.
Fofonoff, N.P., Hayes, S.P. and Millard Jr., R.C. (1974).
WHOI/Brown Micro- profiler: Methods of calibration and data handling. WHOI Technical Report No. 74-89, 64pp (unpublished manuscript)
Knoll, M. (1983).
CTD and current profiler data from JASIN 1978. Meteor Forschungsergebnisse, A/B, No.24, p25-40
Project Information
Joint Air Sea Interaction Experiment (JASIN)
The JASIN Project was designed to study the interaction of the atmospheric and oceanic boundary layers with the larger scale motions of the sea and the air.
The primary aims may be summarized as follows:
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To observe and distinguish between the physical processes causing mixing in the atmospheric and oceanic boundary layers and relate them to the mean properties of the layers.
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To examine and quantify aspects of the momentum and heat budgets in the atmospheric and oceanic boundary layers and fluxes across and between them.
The multiplicity of processes to be sampled necessitated a large experiment and JASIN involved 14 ships and 3 aircraft with more than 50 teams of investigators from 9 countries. Altogether 35 mooring systems were deployed.
The experiment lasted for 2 months from mid-July to mid-September 1978 and comprised 2 intensive measuring periods preceded by a preparatory test period. The project took place in the north Rockall Trough, an area of deep water (1000m - 2000m) several hundred kilometres off the west coast of Scotland.
Data Activity or Cruise Information
Cruise
Cruise Name | 10/78 |
Departure Date | 1978-08-15 |
Arrival Date | 1978-09-14 |
Principal Scientist(s) | Gerold Siedler (Institute of Marine Sciences, Kiel) |
Ship | Planet |
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 |
B | nominal value |
Q | value below limit of quantification |