Metadata Report for BODC Series Reference Number 529350


Metadata Summary

Data Description

Data Category Hydrography time series at depth
Instrument Type
NameCategories
Aanderaa WLR 7 Water Level Recorder  sea level recorders; water temperature sensor
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 wt0004.825
BODC Series Reference 529350
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1999-03-30 08:25
End Time (yyyy-mm-dd hh:mm) 1999-05-18 14:35
Nominal Cycle Interval 600.0 seconds
 

Spatial Co-ordinates

Latitude 52.31980 N ( 52° 19.2' N )
Longitude 4.19530 E ( 4° 11.7' E )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor Depth 21.5 m
Maximum Sensor Depth 21.5 m
Minimum Sensor Height 0.5 m
Maximum Sensor Height 0.5 m
Sea Floor Depth 22.0 m
Sensor Distribution Sensor fixed, measurements made at fixed depths - 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 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 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)
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
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

Comparison with temperature records from a Minilog temperature probe located on the same bottom frame indicates that the temperature channel of the bottom pressure recorder was consistently underestimated water temperature by approximately 0.2 °C.


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 Water Level Recorder Model 7

The Water Level Recorder (WLR) model 7 is a self-contained, high precision instrument specifically designed for recording of ocean water levels through precise measurement of hydrostatic pressure. The WLR records pressure, temperature and conductivity (optional) at regular intervals, enabling precise variations in water level to be calculated. The pressure sensor consists of an oscillating quartz crystal which shifts frequency with the force applied to it. Temperature is measured by a Fenwall thermistor.

The data from the WLR7 are stored in a solid-state data storage unit (DSU) which can store up to 65,500 ten bit, PDC-4 coded words in a set of EEPROMS. Click the link for further details on the WLR7 .

Specifications

Pressure

Oscillator Frequency 36-40 kHz
Resolution 0.001% of range
Repeatability ± 0.01% of full scale
Integration 40 s
Ranges available 0 - 700 kPA (60 m) (standard)
0 - 3500 kPa (340 m) (standard)

Temperature

The thermistor is a Fenwall GB32JM19

Range -3 °C to +35 °C
Accuracy ± 0.1 °C
Resolution 0.04 °C
Response Time 30 s

Conductivity (optional)

Sensor Type Conductivity Cell 3094
Ranges 0 - 77 mmho cm -1 (standard)
0 - 42 mmho cm -1 (on request)
Accuracy ± 0.25 mmho cm -1
Resolution 0.1% of range

Further details can be found in the manufacturer's specification sheet .

Data Processing Notes

This instrument was operating in two modes: a burst mode with a sampling frequency of 0.5 seconds for 20 minutes every 3 hours and an integrated mode with an integration period of 10 minutes.

The present series corresponds to the integrated data. The burst data have not been processed and are available in the originators ASCII format.

Proudman Oceanographic Laboratory Data Processing

Pressure Recorder data processing carried out at POL, Merseyside.

The data have been converted to scientific units using factory calibrations. The time channel has been adjusted to take account of the 600 seconds integration period.

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#825
Platform Categoryfixed benthic node

PROVESS Project POLRIG#825

This mooring was known within PROVESS as 'Rig T'. It was deployed on the western leg of the Southern North Sea Site during the spring of 1999.

Mooring type U-shaped mooring with bottom frame and toroid.
Instruments in bottom frame
(0.5 m above sea-bed)
1.2 MHz RDI ADCP (S/N 253)
InterOcean S4 current meter (S/N 2006)
Wave/tide recorder (S/N 0004)
Minilog Temperature probe (S/N 1362)
Transmissometer (S/N 1686)
On the toroid line
(from 3 m below surface)
10m Thermistor/Conductivity chain (5 sensors, S/N 1461)

Other Series linked to this Data Activity - 541791 541822 541858 541742 529245

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.

Other Series linked to this Fixed Station for this cruise - 529245 529257 529269 529270 529282 529294 529301 529313 529325 529337 529349 541730 541742 541754 541766 541778 541791 541809 541810 541822 541834 541846 541858 541871 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