Metadata Report for BODC Series Reference Number 953286
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
CH62a Sea surface meteorological data quality report
The PAR data were largely unusable due to a problem with the logging system at medium to high light intensities. Where they are available the data channel is the maximum of the readings from the two sensors, to minimise shading effects.
Irradiance data are available for most of the cruise.
Data Access Policy
Open 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.
If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:
"Contains public sector information licensed under the Open Government Licence v1.0."
Narrative Documents
Chelsea Technologies Photosynthetically Active Radiation (PAR) Irradiance Sensor
This sensor was originally designed to assist the study of marine photosynthesis. With the use of logarithmic amplication, the sensor covers a range of 6 orders of magnitude, which avoids setting up the sensor range for the expected signal level for different ambient conditions.
The sensor consists of a hollow PTFE 2-pi collector supported by a clear acetal dome diverting light to a filter and photodiode from which a cosine response is obtained. The sensor can be used in moorings, profiling or deployed in towed vehicles and can measure both upwelling and downwelling light.
Specifications
Operation depth | 1000 m |
Range | 2000 to 0.002 µE m-2 s-1 |
Angular Detection Range | ± 130° from normal incidence |
Relative Spectral Sensitivity | flat to ± 3% from 450 to 700 nm down 8% of 400 nm and 36% at 350 nm |
Further details can be found in the manufacturer's specification sheet.
Decca Navigator System
The Decca Navigator System (DNS) was a hyperbolic radio navigation system that operated by measuring the phase differences between continuous signals from master and slave stations. The differences were then related to hyperbolic lines printed on a chart (also known as lines of lattice). By plotting the readings from two pairs of hyperbolas at any particular instant, the user was able to plot their position instantly. The system operated from WWII until the UK transmitters were switched off at the end of March 2000.
The DNS consisted of groups of at least three shore based transmitter stations (or chains) which comprised one Master and two or three slave stations, usually located 80 to 110 km from the master station and positioned about 120° apart. The accuracy of this system depended on the distance to the baseline, time of day and seasonal effects.
The table below presents the general specifications for this system.
Specifications
Frequency | 70 - 130 kHz |
Accuracy | 50 m (daytime) 200 m (at night) |
Maximum Range | 300 - 400 nm (daytime) 240 nm (at night) |
Further details can be found here.
CH62a Sea surface meteorological instrument details
Meteorological parameters were recorded by a suite of instruments onboard the ship. Instrument details are given in the table below.
Instrument type | Make and model |
Decca | unspecified |
Radiometer | Plymouth Marine Laboratory 2π |
Pyranometer | Unspecified |
CH62a Meteorology Processing Notes
Photosynthetically Active Radiation (PAR)
Photosynthetically active radiation (PAR) was measured using PML 2π PAR sensors mounted on gimballed supports on each side of the ship's monkey island, so that when one is in shadow the other is not.
The PAR meters were calibrated using the following laboratory determined calibrations:
Port: | PAR(µE m-2 s-1) = exp (-4.96*volts + 7.1905) * 0.0375 |
Starboard: | PAR(µE m-2 s-1) = exp (-4.982*volts + 7.0090) * 0.0375 |
CH62a Sea surface Hydrography, Meteorology and Navigation Series
Instrumentation
A suite of parameters were logged from the non-toxic supply, the intake for which was located on the ship's hull, about 2m below the surface.
Operational procedure and data logging
Data were logged by the Research Vessels Services ABC data logging system. The data output units were sampled every 30 seconds by a microprocessor interface (the Level A) which passed time stamped data cycles to a Sun workstation (the Level C) via a buffering system (the Level B). Navigation was updated every two minutes and infilled by linear interpolation. Dissolved oxygen and probe temperature were logged at 15 minute intervals by a PC connected to the Endico controller and transferred to the Level C on floppy disk.
Data Processing
The raw data comprised ADC counts. These were converted into engineering units (degrees for latitude/longitude, volts for PAR meters, fluorometer, transmissometer and nutrients, mmho/cm for conductivity, degC for temperature, metres for bathymetry) by the application of laboratory determined calibrations and salinity was calculated using the algorithm in Fofonoff and Millard (1983). The data were submitted to BODC in this form.
Project Information
North Sea Project
The North Sea Project (NSP) was the first Marine Sciences Community Research project of the Natural Environment Research Council (NERC). It evolved from a NERC review of shelf sea research, which identified the need for a concerted multidisciplinary study of circulation, transport and production.
The ultimate aim of the NERC North Sea Project was the development of a suite of prognostic water quality models to aid management of the North Sea. To progress towards water quality models, three intermediate objectives were pursued in parallel:
- Production of a 3-D transport model for any conservative passive constituent, incorporating improved representations of the necessary physics - hydrodynamics and dispersion;
- Identifying and quantifying non-conservative processes - sources and sinks determining the cycling and fate of individual constituents;
- Defining a complete seasonal cycle as a database for all the observational studies needed to formulate, drive and test models.
Proudman Oceanographic Laboratory hosted the project, which involved over 200 scientists and support staff from NERC and other Government funded laboratories, as well as seven universities and polytechnics.
The project ran from 1987 to 1992, with marine field data collection between April 1988 and October 1989. One shakedown (CH28) and fifteen survey cruises (Table 1), each lasting 12 days and following the same track, were repeated monthly. The track selected covered the summer-stratified waters of the north and the homogeneous waters in the Southern Bight in about equal lengths together with their separating frontal band from Flamborough head to Dogger Bank, the Friesian Islands and the German Bight. Mooring stations were maintained at six sites for the duration of the project.
Table 1: Details of NSP Survey Cruises on RRS Challenger | |
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Cruise No. | Date |
CH28 | 29/04/88 - 15/05/88 |
CH33 | 04/08/88 - 16/08/88 |
CH35 | 03/09/88 - 15/09/88 |
CH37 | 02/10/88 - 14/10/88 |
CH39 | 01/11/88 - 13/11/88 |
CH41 | 01/12/88 - 13/12/88 |
CH43 | 30/12/88 - 12/01/89 |
CH45 | 28/01/89 - 10/02/89 |
CH47 | 27/02/89 - 12/03/89 |
CH49 | 29/03/89 - 10/04/89 |
CH51 | 27/04/89 - 09/05/89 |
CH53 | 26/05/89 - 07/06/89 |
CH55 | 24/06/89 - 07/07/89 |
CH57 | 24/07/89 - 06/08/89 |
CH59 | 23/08/89 - 04/09/89 |
CH61 | 21/09/89 - 03/10/89 |
Alternating with the survey cruises were process study cruises (Table 2), which investigated some particular aspect of the science of the North Sea. These included fronts (nearshore, circulation and mixing), sandwaves and sandbanks, plumes (Humber, Wash, Thames and Rhine), resuspension, air-sea exchange, primary productivity and blooms/chemistry.
Table 2: Details of NSP Process cruises on RRS Challenger | ||
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Cruise No. | Date | Process |
CH34 | 18/08/88 - 01/09/88 | Fronts - nearshore |
CH36 | 16/09/88 - 30/09/88 | Fronts - mixing |
CH56 | 08/07/89 - 22/07/89 | Fronts - circulation |
CH58 | 07/08/89 - 21/08/89 | Fronts - mixing |
CH38 | 24/10/88 - 31/10/88 | Sandwaves |
CH40 | 15/11/88 - 29/11/88 | Sandbanks |
CH42 | 15/12/88 - 29/12/88 | Plumes/Sandbanks |
CH46 | 12/02/89 - 26/02/89 | Plumes/Sandwaves |
CH44 | 13/01/89 - 27/01/89 | Resuspension |
CH52 | 11/05/89 - 24/05/89 | Resuspension |
CH60 | 06/09/89 - 19/09/89 | Resuspension |
CH48 | 13/03/89 - 27/03/89 | Air/sea exchanges |
CH62 | 05/10/89 - 19/10/89 | Air/sea exchanges |
CH50 | 12/04/89 - 25/04/89 | Blooms/chemistry |
CH54 | 09/06/89 - 22/06/89 | Production |
In addition to the main data collection period, a series of cruises took place between October 1989 and October 1990 that followed up work done on previous cruises (Table 3). Process studies relating to blooms, plumes (Humber, Wash and Rhine), sandwaves and the flux of contaminants through the Dover Strait were carried out as well as two `survey' cruises.
Table 3: Details of NSP `Follow up' cruises on RRS Challenger | ||
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Cruise No. | Date | Process |
CH62A | 23/10/89 - 03/11/89 | Blooms |
CH64 | 03/04/90 - 03/05/90 | Blooms |
CH65 | 06/05/90 - 17/05/90 | Humber plume |
CH66A | 20/05/90 - 31/05/90 | Survey |
CH66B | 03/06/90 - 18/06/90 | Contaminants through Dover Strait |
CH69 | 26/07/90 - 07/08/90 | Resuspension/Plumes |
CH72A | 20/09/90 - 02/10/90 | Survey |
CH72B | 04/10/90 - 06/10/90 | Sandwaves/STABLE |
CH72C | 06/10/90 - 19/10/90 | Rhine plume |
The data collected during the observational phase of the North Sea Project comprised one of the most detailed sets of observations ever undertaken in any shallow shelf sea at that time.
Data Activity or Cruise Information
Cruise
Cruise Name | CH62A |
Departure Date | 1989-10-23 |
Arrival Date | 1989-11-03 |
Principal Scientist(s) | Nicholas J P Owens (Plymouth Marine Laboratory) |
Ship | RRS Challenger |
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 |