Metadata Report for BODC Series Reference Number 541754
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
Aanderaa Recording Current Meter Model 7/8
Manufacturer's specifications: recording unit height 49.5cm (RCM8 52.0cm), diameter 12.8cm, vane size 48.5x50.0cm. Meter is designed for depths down to 2000m (RCM8 6000m). It incorporates a spindle which is shackled to the mooring line. The meter is attached to the spindle through a gimbal mounting which permits a maximum 27° deviation of the spindle from the vertical, the meter still remaining horizontal.
Meter comprises :
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Paddle wheel rotor magnetically coupled to an electronic counter
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Vane, which aligns instrument with current flow, has a balance weight ensuring static balance and tail fins to ensure dynamic balance in flows up to 250cm/s.
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Magnetic compass (needle is clamped to potentiometer ring) - direction recorded with 0.35° resolution, 5° accuracy for speeds 5 to 100cm/s, 7.5° accuracy for remaining speeds within 2.5 to 200cm/s range.
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Quartz clock, accuracy better than 2 sec/day within temperature range 0 to 20°C.
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Thermistor (temperature sensor), standard range -2.46 to 21.48°C (max on high range 36.04°C), accuracy 0.05°C, resolution 0.1 per cent of range, 63 per cent response time 12sec.
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Inductive cell conductivity sensor (optional), range 0 to 70mmho/cm standard resolution 0.1 per cent of range.
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Silicon piezoresistive bridge, standard range 0 to 3000 psi (RCM8 to 9000 psi), resolution 0.1% of range.
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Self balancing potentiometer which converts the output from each sensor into a 10 bit binary number for storage on magnetic tape.
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Associated electronics.
A built-in clock triggers the instrument at preset intervals and up to six channels are sampled in sequence. Channel 1 is a fixed reference reading for control purposes and data identification. Channels 2, 3 and 4 represent measurement of temperature, conductivity and pressure. Channels 5 and 6 represent the VECTOR AVERAGED current speed and direction since the previous triggering of the instrument. The number of rotor revolutions and the direction is sampled every 12 seconds and broken into North and East components. Successive components are added and recorded as speed and direction. For recording intervals longer than 10 minutes, speed and direction are sampled 1/50th of recording interval.
It has become common practice in some laboratories to deploy these meters as temperature and conductivity loggers without current measuring capabilities.
The following link will provide the manufacturer specifications:
Manufacturer specificationsAanderaa Current Meter Data Processing
Data Originator's Processing
The following procedures are carried out before the data were supplied to BODC.
Data were downloaded from the instrument logger, and factory calibrations were applied to the current speed channel, and the pressure, conductivity and temperature channels when fitted. Where available, laboratory calibrations of the current direction channels were used; factory formulae were used in their absence. Where no form factor was known for the conductivity sensor, a value of 2.8 was used.
Please note (concerns vector averaged current data): The current data are averaged by the logger over the sampling interval, whereas the pressure, temperature and conductivity data are single point measurements taken at the end of the interval. The data originator has moved the time stamps to the mid-point of the vector averaging sampling interval for all channels without interpolation.
BODC Data Processing and Quality Control
Where pressure sensors were fitted: the data record was compared with the pressure computed from the water depth on deployment and rig geometry. The time series was visually screened for evidence of rig movement (e.g. trawling) and excessive leaning (perhaps due to strong currents).
Where temperature sensors were fitted: the data record was compared with calibrated CTD data taken in the vicinity and checked for agreement within a few tenths of a degree Celsius. Obvious spikes were flagged. Periods of excessively noisy data were noted.
Where conductivity sensors were fitted: salinity (PSS-78) was computed from in-situ temperature and conductivity and a nominal pressure computed from the water depth on deployment and rig geometry. Obvious spikes were flagged.
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:
- Irregularities such as unfeasible values
- Inconsistencies between related information, for example:
- Times for instrument deployment and for start/end of data series
- Length of record and the number of data cycles/cycle interval
- Parameters expected 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 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:
- 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 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:
- Maximum and minimum values of parameters (spikes excluded).
- The occurrence of meteorological events.
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
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 |
---|---|---|---|
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#827 |
Platform Category | subsurface mooring |
PROVESS Project POLRIG#827
This mooring was known within PROVESS as 'Rig V'. It was deployed on the northern leg of the Southern North Sea Site mooring array between Rigs A and Y during the spring of 1999.
Mooring type | U-shaped mooring with spar buoy. |
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Instruments on the sub-surface line | Minilog temperature probes (S/N 2421, 2420, 2419 and 2417) at 1, 4, 10 and 11 m above seabed Aanderaa current meter (S/N 9652) at 3 m above seabed |
Related Data Activity activities are detailed in Appendix 1
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 2
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: POLRIG#827
Related series for this Data Activity 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 |
---|---|---|---|---|
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 |
Appendix 2: 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 |
---|---|---|---|---|
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 |
541810 | Currents -subsurface Eulerian | 1999-03-30 13:45:00 | 52.302 N, 4.2945 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 |
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 |