Metadata Report for BODC Series Reference Number 541871

Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
Sediment Transport and Boundary Layer Equipment Mark II  sea level recorders; current meters; current profilers; water temperature sensor; water pressure sensors
Instrument Mounting fixed benthic node
Originating Country United Kingdom
Originator -
Originating Organization Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Processing Status banked
Project(s) Provess

Data Identifiers

Originator's Identifier stable/pe136
BODC Series Reference 541871

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1999-03-30 11:48
End Time (yyyy-mm-dd hh:mm) 1999-05-19 07:45
Nominal Cycle Interval 60.0 seconds

Spatial Co-ordinates

Latitude 52.30630 N ( 52° 18.4' N )
Longitude 4.30020 E ( 4° 18.0' E )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor Depth 17.7 m
Maximum Sensor Depth 18.5 m
Minimum Sensor Height 1.5 m
Maximum Sensor Height 2.3 m
Sea Floor Depth 20.0 m
Sensor Distribution Scattered at fixed depths - The sensors are scattered with respect to depth but each remains effectively at the same depth for the duration of the series
Sensor Depth Datum Sea floor reference - Depth measured as a height above sea floor but converted into a depth relative to the sea surface according to the same datum as used for sea floor depth (applicable to instrument depths not bathymetric depths)
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface


BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
HEADCM01 1 Degrees Platform_Heading Orientation (horizontal relative to true north) of measurement device {heading}
LCDAEL01 1 Degrees True CurrDir Current direction (Eulerian) in the water body by in-situ current meter and correction to true North
LCSAEL01 1 Centimetres per second CurrSpd_CM Current speed (Eulerian) in the water body by in-situ current meter
LCSAEL02 1 Centimetres per second CurrSpd2 Current speed (Eulerian) in the water body by in-situ current meter
LCSAEL03 1 Centimetres per second CurrSpd3 Current speed (Eulerian) in the water body by in-situ current meter
LCSAEL04 1 Centimetres per second CurrSpd4 Current speed (Eulerian) in the water body by in-situ current meter
PREXPS01 1 Decibars MeasPress_SL Pressure (measured variable) exerted by the water body by fixed in-situ pressure sensor and corrected to read zero at sea level
PTCHEI01 1 Degrees Pitch_(Electromech) Orientation (pitch) of measurement platform by inclinometer
ROLLEI01 1 Degrees Roll_(Electromech) Orientation (roll angle) of measurement platform by inclinometer
TEMPPR01 1 Degrees Celsius Temp Temperature of the water body

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

Records from the pitch and roll sensors indicated that STABLE moved on 13/4/99 between 06:00 and 09:00. Meteorological data for this period indicated that the move occured during a period of strong winds (speeds above 25 knots) suggesting that STABLE might have been hit by rough seas and rocked (records from the transmissometer fixed on STABLE also showed a major decrease in light transmission at that time probably due to sediment resuspension).

Following this event, current speed recorded by Rotor 1 (closest to the sea floor) was consistently lower than that measured by the three other rotors suggesting that the rotor might have been damaged or become obstructed during the event.

Rotor 2 also recorded lower values than Rotors 3 and 4 immediately after the move but appeared to recover after 21/4/99 19:00.

Since these suspect records from Rotors 1 and 2 appear to be correct in terms of relative changes in current speed, the data were not flagged. However users are advised to use their absolute values with caution.

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

Sediment Transport and Boundary Layer Equipment Mark II (STABLE2)

Pop-up STABLE2 is a benthic lander consisting of a large aluminium frame standing on tripod legs, designed and built at the Proudman Oceanographic Laboratory. It is fitted with syntactic foam buoyancy, two Benthos transponding releases, mechanical releases and disposable ballast. When the Benthos releases receive a coded acoustic command from the mother ship, the ballast is released and the instrument pops up to the surface.

Current speeds are measured at four heights by Savonius rotor meters. Current direction is measured by a single vane.

Instruments on the frame

Height above
sea bed
1.950 m D/Q pressure sensor
1.350 m "Mean" logger with temperature sensor and the compass
0.907 m Vane
0.762 m R4 Savonius rotor
0.582 m R3 Savonius rotor
0.402 m R2 Savonius rotor
0.222 m R1 Savonius rotor

For more information refer to POL Report No 37 1994
(Description and Interpretation of Data Recorded by STABLE II During Charles Darwin Cruise 84, OMEX, Goban Spur, January 1994; J.D. Humphery and S.P. Moores).

Data Processing Notes

Additional processing carried out at BODC included:

Data Quality Note

A number of short-lived irregularities was observed in the current speed records of all four rotor current meters. These were characterised by sudden major decreases in current speeds down to very low or null values followed by a progressive recovery. These irregularities which were flagged as suspect values might have been caused either by shading from one of the legs of the lander or by debris being caught in the rotors and hindering their good functioning.

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:

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:

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:

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)


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.


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:

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
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) 1999-03-29
End Date (yyyy-mm-dd) 1999-05-19
Organization Undertaking ActivityProudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPOLRIG#820
Platform Categoryfixed benthic node


This mooring was known within PROVESS as either 'Rig A' or the STABLE mooring. It was one of a cluster of moorings deployed at the main focus of the Southern North Sea Site during the spring of 1999. The rig was deployed by RV Pelagia (cruise PE136) in March 1999 and recovered by RV Belgica (cruise BG9912) in May 1999.

Mooring type U-shaped mooring with spar buoy and STABLE bottom frame.
Instruments mounted on STABLE
(1.5 m above the sea-bed)
Electromagnetic current meter
Savonius rotor current meter
STD-12 Plus #692
Aanderaa current meter fitted with SeaTech transmissometer (S/N 11814)


Other Series linked to this Data Activity - 541766


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 NamePROVESS Southern North Sea Site
CategoryOffshore area
Latitude52° 18.00' N
Longitude4° 18.00' E
Water depth below MSL16.0 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:

BODC image

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)
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.

Other Series linked to this Fixed Station for this cruise - 529245 529257 529269 529270 529282 529294 529301 529313 529325 529337 529349 529350 541730 541742 541754 541766 541778 541791 541809 541810 541822 541834 541846 541858 541895 541902 541926 541938 553141 553294 553301 553313 564243

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