Metadata Report for BODC Series Reference Number 541754


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Aanderaa RCM 7/8 Recording Current Meter  current meters
Instrument Mounting subsurface mooring
Originating Country United Kingdom
Originator -
Originating Organization Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Provess
 

Data Identifiers

Originator's Identifier as09652.827
BODC Series Reference 541754
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1999-03-30 16:55
End Time (yyyy-mm-dd hh:mm) 1999-05-18 13:55
Nominal Cycle Interval 600.0 seconds
 

Spatial Co-ordinates

Latitude 52.43850 N ( 52° 26.3' N )
Longitude 4.35030 E ( 4° 21.0' E )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor or Sampling Depth 16.0 m
Maximum Sensor or Sampling Depth 16.0 m
Minimum Sensor or Sampling Height 3.0 m
Maximum Sensor or Sampling Height 3.0 m
Sea Floor Depth 19.0 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Sensor fixed with measurements made at multiple depths within a fixed range (e.g. ADCP) - The sensor is at a fixed depth, but measurements are made remotely from the sensor over a range of depths (e.g. ADCP measurements)
Sensor or Sampling 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
 

Parameters

BODC CODERankUnitsTitle
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
CNDCPR011Siemens per metreElectrical conductivity of the water body by in-situ conductivity cell
LCDAEL011Degrees TrueCurrent direction (Eulerian) in the water body by in-situ current meter and correction to true North
LCSAEL011Centimetres per secondCurrent speed (Eulerian) in the water body by in-situ current meter
PSALPR011DimensionlessPractical salinity of the water body by conductivity cell and computation using UNESCO 1983 algorithm
TEMPPR011Degrees CelsiusTemperature 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

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 :

  1. Paddle wheel rotor magnetically coupled to an electronic counter

  2. 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.

  3. 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.

  4. Quartz clock, accuracy better than 2 sec/day within temperature range 0 to 20°C.

  5. 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.

  6. Inductive cell conductivity sensor (optional), range 0 to 70mmho/cm standard resolution 0.1 per cent of range.

  7. Silicon piezoresistive bridge, standard range 0 to 3000 psi (RCM8 to 9000 psi), resolution 0.1% of range.

  8. Self balancing potentiometer which converts the output from each sensor into a 10 bit binary number for storage on magnetic tape.

  9. 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 specifications

Aanderaa 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:

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)

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 ActivityProudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPOLRIG#827
Platform Categorysubsurface 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.
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 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)
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
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 IdentifierData CategoryStart date/timeStart positionCruise
529282Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV Pelagia PE136
529294Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV Pelagia PE136
529301Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV Pelagia PE136
529313Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV 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 IdentifierData CategoryStart date/timeStart positionCruise
564206Meteorology -unspecified1999-03-01 00:00:0052.55 N, 4.0583 ENot applicable
564218Meteorology -unspecified1999-03-01 00:00:0052.2739 N, 4.2959 ENot applicable
564243Waves (statistics)1999-03-29 14:08:0052.3022 N, 4.3003 ERV Pelagia PE136
541766Hydrography time series at depth1999-03-29 14:55:0252.3063 N, 4.3002 ERV Pelagia PE136
541809Transmittance/attenuance, turbidity, or SPM conc.1999-03-29 16:49:0052.298 N, 4.2997 ERV Pelagia PE136
541902Fluorescence or pigments1999-03-29 17:00:0052.298 N, 4.2997 ERV Pelagia PE136
529269Hydrography time series at depth1999-03-29 18:45:0052.3632 N, 3.867 ERV Pelagia PE136
529325Hydrography time series at depth1999-03-29 18:49:4052.3632 N, 3.867 ERV Pelagia PE136
541791Transmittance/attenuance, turbidity, or SPM conc.1999-03-30 08:15:0052.3198 N, 4.1953 ERV Pelagia PE136
541742Hydrography time series at depth1999-03-30 08:15:0652.3198 N, 4.1953 ERV Pelagia PE136
541822Currents -subsurface Eulerian1999-03-30 08:17:3052.3198 N, 4.1953 ERV Pelagia PE136
529245Hydrography time series at depth1999-03-30 08:20:0052.3198 N, 4.1953 ERV Pelagia PE136
529350Hydrography time series at depth1999-03-30 08:25:5252.3198 N, 4.1953 ERV Pelagia PE136
541858Currents -subsurface Eulerian1999-03-30 09:04:5952.3198 N, 4.1953 ERV Pelagia PE136
541778Currents -subsurface Eulerian1999-03-30 10:05:0852.3002 N, 4.3002 ERV Pelagia PE136
541895Fluorescence or pigments1999-03-30 11:00:0052.3002 N, 4.3002 ERV Pelagia PE136
541938Water column chemistry1999-03-30 11:01:4052.3002 N, 4.3002 ERV Pelagia PE136
541871Currents -subsurface Eulerian1999-03-30 11:48:0652.3063 N, 4.3002 ERV Pelagia PE136
553141Water column chemistry1999-03-30 12:32:1552.3002 N, 4.3002 ERV Pelagia PE136
541730Hydrography time series at depth1999-03-30 13:15:0652.3032 N, 4.3055 ERV Pelagia PE136
541810Currents -subsurface Eulerian1999-03-30 13:45:0052.302 N, 4.2945 ERV Pelagia PE136
529257Hydrography time series at depth1999-03-30 14:00:0052.3023 N, 4.3067 ERV Pelagia PE136
529349Hydrography time series at depth1999-03-30 14:00:2652.3023 N, 4.3067 ERV Pelagia PE136
541834Currents -subsurface Eulerian1999-03-30 14:05:0052.3023 N, 4.3067 ERV Pelagia PE136
541846Currents -subsurface Eulerian1999-03-30 14:09:5852.3023 N, 4.3067 ERV Pelagia PE136
529282Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV Pelagia PE136
529294Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV Pelagia PE136
529301Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV Pelagia PE136
529313Hydrography time series at depth1999-03-30 16:50:0052.4385 N, 4.3503 ERV Pelagia PE136
529270Hydrography time series at depth1999-03-30 18:15:0052.5682 N, 4.4002 ERV Pelagia PE136
529337Hydrography time series at depth1999-03-30 18:20:2652.5682 N, 4.4002 ERV Pelagia PE136
553313Offshore sea floor pressure series1999-04-01 16:07:5852.3022 N, 4.3003 ERV Pelagia PE136
553294Currents -subsurface Eulerian1999-04-01 16:09:2052.3022 N, 4.3003 ERV Pelagia PE136
553301Hydrography time series at depth1999-04-01 16:09:2052.3022 N, 4.3003 ERV Pelagia PE136
541926Water column chemistry1999-04-02 21:01:4052.298 N, 4.2997 ERV Pelagia PE136