Metadata Report for BODC Series Reference Number 442652

• 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

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

Ranges available:

Temperature

The thermistor is a Fenwall GB32JM19

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.

Proudman Oceanographic Laboratory Pressure Recorder Data Processing

The data are converted to scientific units using factory calibrations. The date and time channel is adjusted to take account of the 40 second integration interval. The integrity of the time stamps is verified by tidal analysis.

Project Information

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:

• River-Atmosphere-Coast Study (RACS)
  • RACS(A) - Atmospheric sub-component
  • RACS(C) - Coasts sub-component
  • RACS(R) - Rivers sub-component
  • BIOTA - Terrestrial salt marsh study
• Land Ocean Evolution Perspective Study (LOEPS)
• Shelf-Edge Study (SES)
• North Sea Modelling Study (NORMS)
• Data Management (DATA)

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.

LOIS Shelf Edge Study (LOIS - SES)

Introduction

SES was a component of the NERC Land Ocean Interaction Study (LOIS) Community Research Programme that made intensive measurements from the shelf break in the region known as the Hebridean Slope from March 1995 to September 1996.

Scientific Rationale

SES was devoted to the study of interactions between the shelf seas and the open ocean. The specific objectives of the project were:

• To identify the time and space scales of ocean-shelf momentum transmission and to quantify the contributions to ocean-shelf water exchange by physical processes.

• To estimate fluxes of water, heat and certain dissolved and suspended constituents across a section of the shelf edge with special emphasis on net carbon export from, and nutrient import to, the shelf.

• To incorporate process understanding into models and test these models by comparison with observations and provide a basis for estimation of fluxes integrated over time and the length of the shelf.

Fieldwork

The SES fieldwork was focussed on a box enclosing two sections across the shelf break at 56.4-56.5 °N and 56.6-56.7 °N. Moored instrument arrays were maintained throughout the experiment at stations with water depths ranging from 140 m to 1500 m, although there were heavy losses due to the intensive fishing activity in the area. The moorings included meteorological buoys, current meters, transmissometers, fluorometers, nutrient analysers (but these never returned any usable data), thermistor chains, colour sensors and sediment traps.

The moorings were serviced by research cruises at approximately three-monthly intervals. In addition to the mooring work this cruises undertook intensive CTD, water bottle and benthic surveys with cruise durations of up to 6 weeks (3 legs of approximately 2 weeks each).

Moored instrument activities associated with SES comprised current measurements in the North Channel in 1993 and the Tiree Passage from 1995-1996. These provided boundary conditions for SES modelling activities.

Additional data were provided through cruises undertaken by the Defence Evaluation and Research Agency (DERA) in a co-operative programme known as SESAME.

Data Activity or Cruise Information

Data Activity

Proudman Oceanographic Laboratory Moored Instrument Rig #710

This rig was deployed as part of the LOIS Shelf-Edge Study at site N140.

Instruments deployed on the rig

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

LOIS (SES) Mooring and CTD Site N140

Site N140 was a fixed station where moorings were deployed during the Land-Ocean Interaction Study (LOIS) Shelf Edge Study (SES). It was also one of nineteen CTD sites on repeat section N, across the Hebridean Slope, occupied by cruises between March 1995 and September 1996.

Instrument Deployment History

The following tables summarise the instruments deployed at this site for which data may be available.

1995

1996

Each different letter in the tables above corresponds to an individual instrument record.

Glossary

• CM = Current meter (Aanderaa or S4)
• BPR = Bottom pressure recorder

Note

• Transmissometers may have been fitted to some of the current meters.
• Other instruments (colour sensors, wave rider) may have been deployed.
• Only periods for which useful data were returned are shown.

Related Fixed Station activities are detailed in Appendix 1

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: LOIS(SES) N140

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.