Metadata Report for BODC Series Reference Number 541810
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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Time Co-ordinates(UT) |
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Parameters |
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Problem Reports
No Problem Report Found in the Database
Data Access Policy
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
Narrative Documents
InterOcean Spherical Solid State Sensor Current Meter S4 series
The S4 family are self-contained current measuring sensors enclosing all necessary solid state electronics for acquiring, processing and outputting data. Data retrieval is accomplished through a serial port without opening the instrument.
The spherical shape of the S4 is a contributing factor in the rejection of the vertical components of water movement and there are no protruding parts or sensor support structures to interfere with the water flow.
The S4 measures the magnitude and direction of the horizontal current motion of the water. Water flows through the electromagnetic field created by the instrument, thereby producing a voltage which is proportional to the magnitude of the water velocity past the sensor. This voltage is then sensed by two pairs of titanium electrodes located symmetrically on the equator of the spherical housing which forms the sensor.
Manufacturer's specifications: Meter (sphere, diameter 25cm) is designed for depths down to 1000m (S4 standard: glass-filled cycloaliphalic epoxy construction with grooved surface for hydrodynamic stability) or down to 6000m (S4D, deep: annealed borosilicate glass version with smooth surface). The meter is shackled directly into the mooring cable by means of an axial titanium load bearing shaft.
Meter comprises:-
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Electromagnetic, 2 axis current speed sensor, range 0 to 350cm/s (standard) 0 to 50 and 0 to 100cm/s (optional), resolution 0.2cm/s (standard) 0.03cm/s (0 to 50 range) 0.06cm/s (0 to 100 range), accuracy 2 per cent reading +/- 1cm/s. The sensor responds to the component of flow normal to its vertical axis.
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Flux-gate magnetometer compass for heading information used to reference the current direction to magnetic north, compass range 360°, resolution 0.5°, accuracy 2°, tilt +/- 25° for specified accuracy.
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Temperature stable quartz oscillator clock, accuracy 12 minutes/year.
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Optional automatic tilt compensation i.e. the allowable tilt of the meter from the vertical at which the vertical cosine response is fully corrected, angle range +/- 45°, resolution 0.6°, accuracy (speed correction) 1 per cent (angle output) 0.25°.
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Optional semiconductor (thermistor or platinum) temperature sensor, range -5 to +45 °C, resolution 0.05 °C, accuracy 0.2 °C, response time at 63 per cent 1 min (1.5 sec thermistor or 60msec platinum).
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Optional conductive conductivity sensor, range 5 to 70mS/cm, resolution 0.1mS/cm, accuracy 0.2mS/cm (optional inductive sensor, range 1 to 70mS/cm).
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Optional semiconductor strain gauge pressure sensor, range 0 to 1000dBar (70M option), resolution 1dBar (4mm with 70M option), accuracy 0.25 per cent fs.
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Recorder, CMOS static RAM microprocessor, 64KByte (128K or 256KByte optional) performs vector averaging, burst sampling and adaptive sampling.
Available versions of the S4 are listed in the table below:
S4RT | Basic S4 current meter without memory installed, for real-time monitoring applications only. |
S4 | The basic S4 current measuring instrument, with current speed and direction sensors and internal memory from 64K to 1 megabyte of solid-state memory. |
S4DW | S4 current meter directional wave measuring instrument. Includes 1 megabyte of memory, 70 meter high-resolution depth, adaptive sampling, and Lithium battery pack, standard. |
S4P | S4 instrument outfitted for profiling applications. Fitted with fast response Platinum temperature sensor, inductive flow- through conductivity sensor, and high-resolution depth sensor as standard. Memory size may be from 64K to 1 megabyte. |
S4D | Deep water S4 instrument for use to depths of 6,000 meters. |
S4A | Advanced current measuring instrument with large memory capacity, and dual-mode logging capability. Memory size may be 32-256 megabytes. Includes high speed binary down-loads using Zmodem protocol with 32 bit CRC error checking. Adaptive current sampling is standard on this instrument. |
S4ADW | Large memory capacity S4 directional wave measuring instrument. Includes 32 to 256 megabyte memory, 70 meter high-resolution depth sensor, and Lithium battery pack, standard. |
S4ADW-i | New generation of S4ADW directional wave measuring instrument providing internally-processed directional wave data for direct output from the instrument without the need for external analysis software. Ideal multi-purpose oceanographic instrument for integrated-system applications requiring pre-processed output directly into a datalogger, PLC, modem, or other external device without need for PC computer. Used for directional wave, current, and tide measurements, with additional parameters available. Includes long-life lithium battery, and internal memory sizes from 32MB to 256MB. |
S4AP | An S4A instrument outfitted for profiling applications. Fitted with fast response Platinum temperature sensor, inductive flow-through conductivity sensor, and high- resolution depth sensor, standard. Memory size may be 32-256 megabytes. |
S4AD | Deep water S4A instrument for use to depths of 6,000 meters. Has all the same features and options as available with the standard S4A. |
S4AH | Same as S4A but uses 5 Hz sampling rate instead of 2 Hz. S4AHDW, S4AHP, S4AHD are 5 Hz models of the units listed above. |
Further details are available from the manufacturer's specification sheet.
BODC Current Meter Screening
BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.
Header information is inspected for:
- Irregularities such as unfeasible values
- Inconsistencies between related information. For example:
- Depths of meter and sea bed.
- Times for mooring deployment and for start/end of data series.
- Length of record or number of data cycles, the cycle interval, the clock error and the period over which accrued.
- Parameters stated as measured and the parameters actually present in the data cycles.
- Originator's comments on meter/mooring performance and data quality.
Documents are written by BODC highlighting irregularities which cannot be resolved.
Data cycles are inspected using time 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 following types of irregularity, each relying on visual detection in the time series plot, are amongst those which may be flagged as suspect:
- Spurious data at the start or end of the record.
- Obvious spikes occurring in periods free from meteorological disturbance.
- A sequence of constant values in consecutive data cycles.
If a large percentage of the data is affected by irregularities, deemed abnormal, then instead of flagging the individual suspect values, a caution may be documented. Likewise documents will highlight irregularities seen in the current vector scatter plots such as incongruous centre holes, evidence of mooring 'knock-down', abnormal asymmetry in tidally dominated records or gaps as when a range of speeds or directions go unregistered due to meter malfunction.
The term 'knock-down' refers to the situation when the 'drag' exerted on a mooring at high current speeds may cause instruments to tilt beyond the angle at which they are intended to operate. At this point the efficiency of the current sensors to accurately record the flow is reduced.
Inconsistencies between the characteristics of the data set and those of its neighbours are sought, and where necessary, documented. This covers inconsistencies in the following:
- Maximum and minimum values of parameters (spikes excluded).
- The orientation and symmetry of the current vector scatter plot.
- The direction of rotation of the current vectors.
- The approximate amplitude and periodicity of the tidal currents.
- The occurrence of meteorological events and, finally, for series for which no time check was possible, the phase.
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.
Data Processing Notes
The recorder of this S4 current meter was set to continuous mode with a vector averaging rate of 1200 half seconds.
Data processing was carried out at the Proudman Oceanographic Laboratory, Merseyside, UK. The time channel was adjusted to take into account the averaging period, by adding half the sampling interval to the recorded scan time.
The current data were corrected for a magnetic deviation of 2.2° W.
Project Information
PROcesses of Vertical Exchange in Shelf Seas (PROVESS)
Introduction
PROVESS was an interdisciplinary study of the vertical fluxes of properties through the water column and the surface and bottom boundary layers. The project was funded by the European Community MAST-III programme (MAS3-CT97- 0159) and ran from March 1998 to May 2001.
Scientific Rationale
PROVESS was based on the integration of experimental, theoretical and modelling studies with the aim of improving understanding and quantification of vertical exchange processes in the water column, in particular in the surface and benthic boundary layers and across the> pycnocline. PROVESS also explored mechanisms of physical-biological coupling in which vertical exchanges and turbulence significantly affect the environmental conditions experienced by the biota with particular reference to aggregation, flocculation, sedimentation and trophic interactions.
Fieldwork
The experimental phase of the project was carried out at two contrasting sites in the North Sea: the northern North Sea site (NNS) and the southern North Sea site (SNS).
The two sites had the following characteristics:
SNS | NNS | |
---|---|---|
Position | 52° 15.0' N, 4° 17.0' E | 59° 20.0' E, 1° 00.0' E |
Time of year | April-May | September-November |
Water depth (m) | 16 | 100 |
M2 max amplitude (m s-1) | 0.75 | 0.15 |
Max current (m s-1) | 1.0 | 0.6 |
Delta T (deg C) | mixed | 7-1 |
Thermocline depth (m) | mixed | 35-100 |
Delta S | 1 | small |
Halocline depth (m) | 5-10 | cf. thermocline depth |
Max wind speed (m s-1) | 20 | 25 |
Max wave height (m) | 5 | 10 |
Max wave period (s) | 8 | 10 |
Internal motion | No | Yes |
Sediment | muddy-sand | muddy-sand |
Biology | eutrophic | oligotrophic |
At both locations measurements were concentrated at a central position with additional measurements being made to estimate horizontal gradients. Moored instruments (including current meters, temperature and pressure sensors, fluorometers, transmissometers, nutrient analysers and meteorological sensors) were deployed between 7 September and 5 November 1998 at the NNS and between 29 March and 25 May 1999 at the SNS. Each experiment was supported by intensive measurement series made from oceanographic ships and involving turbulence dissipation profiler CTD, particle size profilers, optical profilers, benthic sampling and water bottle sampling.
Details of the cruises were as follows:
Site | Ship (nationality) | Cruise Mnemonic | Date |
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NNS | Valdivia (GER) | VA174 | 5 - 17 Sep 1998 |
Dana (DK) | D1198 | 14 - 26 Oct 1998 | |
Pelagia (NL) | PE125 | 19 - 30 Oct 1998 | |
Challenger (UK) | CH140 | 22 Oct - 9 Nov 1998 | |
SNS | Pelagia (NL) | PE135 | 29 Mar - 9 Apr 1999 |
Mitra (NL) | MT0499 | 19 - 30 Apr 1999 | |
Belgica (BE) | BG9912 | 17 - 21 May 1999 |
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 1999-03-30 |
End Date (yyyy-mm-dd) | 1999-05-18 |
Organization Undertaking Activity | Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool) |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | POLRIG#822 |
Platform Category | subsurface mooring |
PROVESS Project POLRIG#822
This mooring was known within PROVESS as 'Rig D'. It was one of a cluster of moorings deployed at the main focus of the Southern North Sea Site during the spring of 1999.
Mooring type | Single string mooring with toroid (J-rig). |
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Instrument | S4 current meter (S/N 1644) 4 m below surface. |
Cruise
Cruise Name | PE136 |
Departure Date | 1999-03-29 |
Arrival Date | 1999-04-09 |
Principal Scientist(s) | Hans van Haren (Royal Netherlands Institute for Sea Research) |
Ship | RV Pelagia |
Complete Cruise Metadata Report is available here
Fixed Station Information
Fixed Station Information
Station Name | PROVESS Southern North Sea Site |
Category | Offshore area |
Latitude | 52° 18.00' N |
Longitude | 4° 18.00' E |
Water depth below MSL | 16.0 m |
PROVESS Southern North Sea Site
Eleven mooring packages were deployed at PROVESS Southern North Sea site by Pelagia cruise PE136 in March 1999. One of these (Rig U) was lost, the NIOZ mooring was recovered by PE136 in April 1999 and the remaining nine were recovered by either RV Belgica cruise BG9912 (8 moorings) or RV Zirfea (Rig V) in May 1999.
The layout of the mooring array was:
The asterisk represents an array of five moorings as detailed in the inset map.
Mooring data
The data returned from each rig were as follows:
Rig identifier | Data | |
---|---|---|
A | POLRIG#820 | Near-bed currents Temperature, salinity and attenuance |
B | POLRIG#821 | ADCP currents Water level Thermistor plus conductivity chain |
D | POLRIG#822 | Currents |
H | POLRIG#824 | Currents Nutrients (nitrate + nitrite, silicate) Chlorophyll |
G | POLRIG#823 | Surface attenuance, nutrients (nitrate + nitrite) and chlorophyll |
NIOZ | ADCP currents Thermistor chain Wave statistics (considered suspect) | |
V | POLRIG#827 | Currents Temperature (4 depths) |
Y | POLRIG#829 | Water level Near-bed temperature |
T | POLRIG#825 | ADCP currents Water level Thermistor plus conductivity chain |
U | Unknown | None |
X | POLRIG#828 | Water level Near-bed temperature |
CTD data
A total of 356 CTD casts were also collected during the three cruises surveying this area. These include:
Cruise identifier | Cruise dates | No. of CTD casts |
---|---|---|
RV Pelagia (#136) | 29 March - 09 April 1999 | 133 |
Mitra (#0499) | 19 April - 30 April 1999 | 170 |
RV Belgica (#9912) | 17 May - 21 May 1999 | 53 |
Additonal data
Supporting meteorological data (including sea surface temperature and wave statistics) from two platforms (52° 33' N, 4° 3.5' E and 52° 16.4' N, 4° 17.8' E) were supplied to the project and are held by BODC. These series run from the beginning of March 1999 until the end of May 1999.
Related Fixed Station activities are detailed in Appendix 1
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 |
Appendix 1: PROVESS Southern North Sea Site
Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.
If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
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564206 | Meteorology -unspecified | 1999-03-01 00:00:00 | 52.55 N, 4.0583 E | Not applicable |
564218 | Meteorology -unspecified | 1999-03-01 00:00:00 | 52.2739 N, 4.2959 E | Not applicable |
564243 | Waves (statistics) | 1999-03-29 14:08:00 | 52.3022 N, 4.3003 E | RV Pelagia PE136 |
541766 | Hydrography time series at depth | 1999-03-29 14:55:02 | 52.3063 N, 4.3002 E | RV Pelagia PE136 |
541809 | Transmittance/attenuance, turbidity, or SPM conc. | 1999-03-29 16:49:00 | 52.298 N, 4.2997 E | RV Pelagia PE136 |
541902 | Fluorescence or pigments | 1999-03-29 17:00:00 | 52.298 N, 4.2997 E | RV Pelagia PE136 |
529269 | Hydrography time series at depth | 1999-03-29 18:45:00 | 52.3632 N, 3.867 E | RV Pelagia PE136 |
529325 | Hydrography time series at depth | 1999-03-29 18:49:40 | 52.3632 N, 3.867 E | RV Pelagia PE136 |
541791 | Transmittance/attenuance, turbidity, or SPM conc. | 1999-03-30 08:15:00 | 52.3198 N, 4.1953 E | RV Pelagia PE136 |
541742 | Hydrography time series at depth | 1999-03-30 08:15:06 | 52.3198 N, 4.1953 E | RV Pelagia PE136 |
541822 | Currents -subsurface Eulerian | 1999-03-30 08:17:30 | 52.3198 N, 4.1953 E | RV Pelagia PE136 |
529245 | Hydrography time series at depth | 1999-03-30 08:20:00 | 52.3198 N, 4.1953 E | RV Pelagia PE136 |
529350 | Hydrography time series at depth | 1999-03-30 08:25:52 | 52.3198 N, 4.1953 E | RV Pelagia PE136 |
541858 | Currents -subsurface Eulerian | 1999-03-30 09:04:59 | 52.3198 N, 4.1953 E | RV Pelagia PE136 |
541778 | Currents -subsurface Eulerian | 1999-03-30 10:05:08 | 52.3002 N, 4.3002 E | RV Pelagia PE136 |
541895 | Fluorescence or pigments | 1999-03-30 11:00:00 | 52.3002 N, 4.3002 E | RV Pelagia PE136 |
541938 | Water column chemistry | 1999-03-30 11:01:40 | 52.3002 N, 4.3002 E | RV Pelagia PE136 |
541871 | Currents -subsurface Eulerian | 1999-03-30 11:48:06 | 52.3063 N, 4.3002 E | RV Pelagia PE136 |
553141 | Water column chemistry | 1999-03-30 12:32:15 | 52.3002 N, 4.3002 E | RV Pelagia PE136 |
541730 | Hydrography time series at depth | 1999-03-30 13:15:06 | 52.3032 N, 4.3055 E | RV Pelagia PE136 |
529257 | Hydrography time series at depth | 1999-03-30 14:00:00 | 52.3023 N, 4.3067 E | RV Pelagia PE136 |
529349 | Hydrography time series at depth | 1999-03-30 14:00:26 | 52.3023 N, 4.3067 E | RV Pelagia PE136 |
541834 | Currents -subsurface Eulerian | 1999-03-30 14:05:00 | 52.3023 N, 4.3067 E | RV Pelagia PE136 |
541846 | Currents -subsurface Eulerian | 1999-03-30 14:09:58 | 52.3023 N, 4.3067 E | RV Pelagia PE136 |
529282 | Hydrography time series at depth | 1999-03-30 16:50:00 | 52.4385 N, 4.3503 E | RV Pelagia PE136 |
529294 | Hydrography time series at depth | 1999-03-30 16:50:00 | 52.4385 N, 4.3503 E | RV Pelagia PE136 |
529301 | Hydrography time series at depth | 1999-03-30 16:50:00 | 52.4385 N, 4.3503 E | RV Pelagia PE136 |
529313 | Hydrography time series at depth | 1999-03-30 16:50:00 | 52.4385 N, 4.3503 E | RV Pelagia PE136 |
541754 | Currents -subsurface Eulerian | 1999-03-30 16:55:07 | 52.4385 N, 4.3503 E | RV Pelagia PE136 |
529270 | Hydrography time series at depth | 1999-03-30 18:15:00 | 52.5682 N, 4.4002 E | RV Pelagia PE136 |
529337 | Hydrography time series at depth | 1999-03-30 18:20:26 | 52.5682 N, 4.4002 E | RV Pelagia PE136 |
553313 | Offshore sea floor pressure series | 1999-04-01 16:07:58 | 52.3022 N, 4.3003 E | RV Pelagia PE136 |
553294 | Currents -subsurface Eulerian | 1999-04-01 16:09:20 | 52.3022 N, 4.3003 E | RV Pelagia PE136 |
553301 | Hydrography time series at depth | 1999-04-01 16:09:20 | 52.3022 N, 4.3003 E | RV Pelagia PE136 |
541926 | Water column chemistry | 1999-04-02 21:01:40 | 52.298 N, 4.2997 E | RV Pelagia PE136 |