Metadata Report for BODC Series Reference Number 172122

• 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

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

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

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:

1. 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.

2. 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

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:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle: