Metadata Report for BODC Series Reference Number 576545


Metadata Summary

Data Description

Data Category Offshore sea floor pressure series
Instrument Type
NameCategories
Aanderaa WLR 5 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) LOIS River-Atmosphere-Coast Study (RACS)
Land Ocean Interaction Study (LOIS)
 

Data Identifiers

Originator's Identifier wr1038.613
BODC Series Reference 576545
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1993-11-26 09:10
End Time (yyyy-mm-dd hh:mm) 1993-12-08 15:20
Nominal Cycle Interval 600.0 seconds
 

Spatial Co-ordinates

Latitude 53.84330 N ( 53° 50.6' N )
Longitude 0.15000 E ( 0° 9.0' E )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor Depth 26.5 m
Maximum Sensor Depth 26.5 m
Minimum Sensor Height 0.5 m
Maximum Sensor Height 0.5 m
Sea Floor Depth 27.0 m
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed 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
 

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)
PRSTPS01 1 Decibars TotPressSeaFL Pressure (measured variable) exerted by the water body plus atmosphere by fixed in-situ pressure sensor
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

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 Bottom Pressure Recorder Models 5 and 6

The water level recorder models 5 and 6 are self-contained, high precision instruments for recording of the water level by precise measurement of hydrostatic pressure. 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. Data are stored on magnetic tape

Specifications

Pressure

Oscillator Frequency 36-40 kHz
Resolution 0.001% of full scale
Integration 40 seconds

Ranges available:

WLR5 0-100psi, 0-400psi (standard), 0-900psi
WLR6 0-5000psi (deep water version)

Temperature

The thermistor is a Fenwall GB32JM19

Range -3 °C to +35 °C
Accuracy ±0.1 °C
Resolution 0.04 °C
Response Time 2 minutes

Offshore Sea Floor Pressure 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:

  1. Irregularities such as suspect values.

  2. Inconsistencies between related information, for example depths of meter and sea bed; times of 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; originator's comments on meter/mooring performance, data quality and parameters measured and the parameters actually present in the data cycles. Documents are written by BODC highlighting irregularities which cannot be resolved.

Data cycles are inspected via time series plots of parameters. These plots undergo intrinsic and extrinsic screening to detect suspect values within the data cycles themselves and inconsistencies when compared with adjacent data sets. 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:

  1. Spurious data at the start or end of the record.

  2. Obvious spikes of non oceanographic origin.

  3. A sequence of constant values in consecutive data cycles.

If a large percentage of the data are affected by irregularities, deemed abnormal, then instead of flagging the individual suspect values, a caution may be documented.

Inconsistencies between the characteristics of the data set and those of its neighbours, as for example between the maximum and minimum values of the parameters (spikes excluded) are, where necessary, documented.

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.

POL Monitoring Platform

The POL monitoring platform (PMP) was developed to accommodate several instruments at once. It consists of a ballasted (275kg) light-weight frame (approx. 1.94m x 1.39m), onto which an acoustic release and buoyancy tanks are attached. Prior to deployment, the various instruments are bolted into place.

Typically a PMP holds a transmissometer, a current meter, an ADCP and a water level recorder. The frame is positioned on the sea-bed with a surface marker buoy.

On recovery, the frame separates from the ballast and rises to the surface. The ballast can be attached by a nylon spooler line to the PMP frame, which enables the entire mooring to be recovered.

LOIS (RACS) Holderness Experiment Data Collection and Processing

Data Collection and Processing - Waveriders

Datawell waverider buoys were deployed at sites N1, N2 and N3 with the buoys at the latter two sites recording directional data. Due to the shallow depths one rubber cord was used in each mooring, whereas two are recommended by Datawell to reduce mooring effects. Datawell waverider buoys calculate spectra and mean wave parameters on board before transmission to a shore station for storage (Datawell, 1995). Eight consecutive 200 second blocks are averaged after spectral analysis. The first and last 32 samples out of a total of 256 are tapered with a cosine taper and the taper is corrected for after averaging. Peak frequency and quality control flags were computed from the spectra. Quality control checks gave 2 per cent high frequency flags at N2 and 1 per cent at N3, with very few low frequency flags.

The recorded time for N1 data is the start of the burst, while the recorded time for N2 and N3 data is the time of receipt of transmission (approximately 40 minutes after the start time of the burst).

Data Collection and Processing - Pressure Recorders

Pressure wave recorders were mounted at 0.35m above the sea bed on PMPs (POL monitoring packages) deployed at stations N1 - N4 and S1 - S4. The pressure recorders used consisted of a pressure sensor in a standard Aanderaa casing. An oil-filled capillary tube was attached to the diaphragm housing to reduce flow effects on the sensor. Burst data were recorded at 2Hz for 20 minutes every 3 hours. Wolf gives details of the processing and correction procedures used on these data.

Data Collection and Processing - S4 Current Meters

InterOcean S4 current meters were mounted at 0.8m above the sea bed on PMPs (POL monitoring packages) deployed at stations N1 - N3 and S1 - S4. The current meters at the inner stations (N1 and S1) included a pressure sensor which allowed directional wave measurements to be made. this version of the S4 is referred to as the S4DW. The standard S4 meters measured 1 minute bursts of data while the S4DWs measured 20 minute bursts at 2Hz with consecutive samples averaged to give 1Hz output.

General Information

Winds were observed at three coastal locations. The observed local wind regime clustered about directions 000 degrees and 200 degrees with maximum speeds of 11.2 m/s and 17.4 m/s respectively.

Repeated CTD profiles were obtained for stations N2 - N4 and S2 - S4.

Instrument Intercomparison

Wolf describes the three instruments as giving acceptable agreement. The S4DWs and the waveriders are in quite close agreement for wave height and the peak wave period is in good agreement for all instruments most of the time. The bottom mounted instruments (as expected) do not always detect a high frequency peak, but are generally in close agreement validating the instrument response. The pressure recorder results for Hs show a gradual worsening in agreement with the waverider results, although other parameters remained in good agreement. Wolf discusses possible causes.

References

Datawell bv, Zomerlustraat 4, 2012 LM Haarlem, the Netherlands (1995).
Operation and Service Manual for "Directional Waverider" from serial no. 30109 and including 30076, 30101, 30106, 30108.

Prandle, D. (1994).
Holderness experiment - the observational programme. LOIS issue no. 2.

Wolf, J. (1996).
The Holderness Project Wave Data. Proudman Oceanographic Laboratory Internal Document No. 89.


Project Information

LOIS River-Atmosphere-Coast Study (LOIS - RACS)

Introduction

The Land-Ocean Interaction Study (LOIS) was a NERC research programme designed to study processes in the coastal zone. The Rivers, Atmosphere and Coasts Study (RACS) was a major component of LOIS that looked at land-sea interactions in the coastal zone and the major exchanges (physical, chemical and biological) between rivers and estuaries and the atmosphere. The study focused on the east coast of the UK from the Wash to the Tweed.

RACS included several sub-components

RACS (A) was coordinated by the University of East Anglia and RACS (C) by the Plymouth Marine Laboratory.

RACS (A)

The bulk of the RACS (A) data set was collected during two field campaigns in the winter (October/November) of 1994 and the summer (May/June) of 1995. During these campaigns data were collected continuously from the University of East Anglia Atmospheric Observatory at Weybourne on the north Norfolk coast. An instrumented vessel was stationed offshore to provide a second sampling site to allow changes in a given air mass to be monitored. The Imperial College Jetstream research aircraft made one flight during each campaign to provide a link between the two surface stations. The Jetstream made four additional flights in 1996 and 1997.

RACS (C)

The coastal oceanographic survey

The coastal oceanographic data set was collected during a series of 17 RRS Challenger cruise legs. Most cruises covered two survey grids. One from Great Yarmouth to the Humber designed around the distribution of the sandbanks and a second simple zig-zag grid from the Humber to Berwick on Tweed. A large number of anchor stations, usually over one or two tidal cycles, were worked in the area of the Humber mouth or the Holderness coast.

The Humber estuarine study

The Humber estuarine data set was collected during a series of 33 campaigns on the Environment Agency vessels Sea Vigil and Water Guardian in the Humber, Trent and Ouse river systems at approximately monthly intervals between June 1993 and December 1996. Each campaign consisted of two or three one-day cruises. The tracks covered the estuary from the tidal limits of both Trent and Ouse to Spurn Point. Instrumental and sample data are available from a series of fixed stations that were sampled during every campaign.

The Tweed estuarine study

The Tweed estuarine data set was collected during a series of 13 campaigns using RV Tamaris in association with a rigid inflatable vessel at approximately monthly intervals between July 1996 and July 1997. Each campaign covered the tidal reaches of the River Tweed.

The Holderness experiment

The Holderness Experiment was designed to monitor the process of sediment transport along the Holderness coastline. It consisted of three moored instrument deployments during the winters of 1993-1994, 1994-1995 and 1995-1996. Mooring platforms were deployed at eight stations along two lines off the Holderness coast. A northerly and a southerly line of four stations each were used (N1 - N4 and S1 to S4) with the lowest numbers being inshore. Both lines were approximately perpendicular to the coast, although the S4 station lay to the south of the S line, off Spurn Head.


Land Ocean Interaction Study (LOIS)

Introduction

The Land Ocean Interaction Study (LOIS) was a Community Research Project of the Natural Environment Research Council (NERC). The broad aim of LOIS was to gain an understanding of, and an ability to predict, the nature of environmental change in the coastal zone around the UK through an integrated study from the river catchments through to the shelf break.

LOIS was a collaborative, multidisciplinary study undertaken by scientists from NERC research laboratories and Higher Education institutions. The LOIS project was managed from NERC's Plymouth Marine Laboratory.

The project ran for six years from April 1992 until April 1998 with a further modelling and synthesis phase beginning in April 1998 and ending in April 2000.

Project Structure

LOIS consisted of the following components:

Marine Fieldwork

Marine field data were collected between September 1993 and September 1997 as part of RACS(C) and SES. The RACS data were collected throughout this period from the estuaries and coastal waters of the UK North Sea coast from Great Yarmouth to the Tweed. The SES data were collected between March 1995 and September 1996 from the Hebridean slope. Both the RACS and SES data sets incorporate a broad spectrum of measurements collected using moored instruments and research vessel surveys.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1993-11-26
End Date (yyyy-mm-dd) 1993-12-08
Organization Undertaking ActivityProudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPOLRIG#613
Platform Categoryfixed benthic node

Proudman Oceanographic Laboratory Monitoring Platform Rig#613

The rig was deployed as part of the LOIS RACS study at site HM3

Rig Position 53.8433 ° N, 0.15 ° E
Water depth 27.0 m
Deployed on cruise CH108B
Mooring deployed on 26 November 1993 09:30
Mooring recovered on 08 December 1993 15:00
Period of deployment 13.2 days
Data available ADCP - Yes
Water Level - Yes

Cruise

Cruise Name CH108B
Departure Date 1993-11-25
Arrival Date 1993-12-10
Principal Scientist(s)Nick Owens (Newcastle University Department of Marine Science and Coastal Management)
Ship RRS Challenger

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameHolderness Site HM3
CategoryCoastal location
Latitude53° 50.60' N
Longitude0° 9.00' E
Water depth below MSL27.0 m

LOIS RACS (Holderness Experiment) Mooring Site HM3

Site used during 1993 preliminary study period.

Position 53° 50.60' N 0° 09.00' E
Water Depth 27.0 m
Magnetic variation 4.0 degrees west

Other Series linked to this Fixed Station for this cruise - 449699 576662 832397

Other Cruises linked to this Fixed Station (with the number of series) - CH108A (4)


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