Metadata Report for BODC Series Reference Number 1367193

• 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

RD Instruments 300kHz Workhorse Sentinel Acoustic Doppler Current Profiler

Specifications

The manufacturer's specification document can be found here

JC088 moored ADCPs (Sites SD, SE, SF and SG): Originator's data processing

Sampling Strategy

RRS James Cook cruise JC088 was the second of two cruises funded by the NERC 'Fluxes Across the Sloping Topography of the North East Atlantic (FASTNEt)' Consortium. JC088 was a 26 day cruise sailing on 28 June 2013 from King George V Dock, Govan to the Malin Shelf edge where inline/single point and bed frame moorings were deployed before returning to Southampton on 24 July 2013.

Setup Configuration

Data Processing

The Originator has supplied quality controlled data for moorings SD, SE, SF, SG in Matlab structure format from three different types of instruments.

Binary data from the RDI Workhorse sentinel instruments were exported into Matlab files using the WinADCP software (v1.14) and then converted into Matlab data structures. Binary data from the Flowquest instruments were converted to ascii using the Flowquest software and then converted into Matlab data structures.

Quality Control

SE bed frame

The following quality control has been applied by the Originator to the raw velocity data. Data were removed if the associated error velocity was > 0.15 m/s and if any of the beams were flagged as bad.

SE inline/single point

The following quality control has been applied by the Originator to the raw velocity data. Data were removed if the associated error velocity was > 0.15 m/s and if any of the beams were flagged as bad. The Originator removed data in bin 120 meters above the Sea Bed as this was contaminated.

SF2

The following quality control has been applied by the Originator. A correction for magnetic declination = -5.533° (magnetic north to the west of true north) has been applied. Velocity data contaminated by strong sea surface echos has been removed and the bin nearest the transducer due to high signal to noise ratios and suspect velocities has also been removed. The total water depth was created from the nearest SEACAT SBE 16plus (SN 4848).

SG

The Originator applied the following quality control to data at this site. A correction for magnetic declination = -5.4° (magnetic north to the west of true north) has been applied. Velocity data contaminated by strong sea surface echos have been removed and the bin nearest the transducer due to high signal to noise ratios and suspect velocities has also been removed. The total water depth was created from the nearest SEACAT SBE 16plus (SN 5309).

SD

The ADCP suffered a serious time drift over its deployment. This was estimated to be 8 seconds drift per 3 minute ensemble. This equated to the clock being approximately 20 hours behind once recovered. The Originator has therefore linearly stretched the time as best as possible to remove this error and supplied the corrected data in another Matlab structured file. The corrected file did not include all the parameters in the original file. The parameters not included were percentage good and temperature. These parameters are not being ingested by BODC, but are available (in the uncorrected drift files) upon request.

The Originator has applied a correction for magnetic declination = -5.75° (magnetic north to the west of true north). Poor quality velocity data was removed around 60 meters above the Sea bed. The total water depth was created from pressure data from the nearest MicroCAT (SN 9113).

Merged SE ADCP data

The Originator merged the bed frame and inline/single point 300 kHz ADCP data to provide the best possible full water column profile. Data were averaged onto coincident 1 min grids and then merged at 70 metres.

Lagged cross correlations reveal that the velocities recorded by the bed frame ADCP lag those from the in-line/single point instrument (a consequence of the frame and inline/single point mooring being 680 m apart). This lag was calculated by considering the whole time series and was applied before the data sets were merged. The Originator has applied a correction for magnetic declination = -5.63° (magnetic north to the west of true north). The total water depth was created from pressure data from the nearest SEACAT SBE 16plus (SN 4597).

The merged file for SE inline/single point and SE bed frame is not being ingested by BODC but is available on request.

The Originator states in all sites that further quality control has been left to the discretion of the end user.

Field Calibrations

No field calibrations were undertaken.

JC088 moored ADCPs (Sites SD, SE, SF and SG): Processing by BODC

Data from five ADCPs arrived at BODC in Matlab structured files. Data from two ADCPs were from short term inline/single point moorings (SE and SD) and three ADCPSs were fixed to bed frames (SE, SF2 and SG). The following table shows how the variables within the files were mapped to appropriate BODC parameter codes:

The reformatted data were visualised using BODC's in-house visualisation software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate absent data value and setting the quality control flag.

Project Information

Fluxes Across Sloping Topography of the North East Atlantic (FASTNEt)

Background

The FASTNEt consortium was funded to deliver NERC's Ocean Shelf Edge Exchange Programme. Commencing in October 2011, this four year study aims to couple established observational techniques, such as moorings and CTDs, with the very latest in autonomous sampling initiatives - including use of Autosub Long Range and gliders. With the aid of novel model techniques, these observations will be utilised to construct a new paradigm of Ocean/Shelf exchange.

Shelf edge regions mark the gateway between the world's deep oceans and shallower coastal seas, linking terrestrial, atmospheric and oceanic carbon pools and influencing biogeochemical fluxes. Shelf edge processes can influence near-shore productivity (and fisheries) and ultimately affect global climate.

FASTNEt brings together researchers from multiple UK organisations. Further collaboration has been established with five Project Partners: the UK Met Office, Marine Scotland Science, Agri-Food and Biosciences Institute, Marine Institute Ireland and Scripps Institution of Oceanography.

Scientific Objectives

• To determine the seasonality of physical gradients and exchange across the shelf edge by deploying new observational technologies (gliders, Autosub Long Range) and established techniques (long term moorings, drifters)
• To quantify key exchange mechanisms and to collect new data targeted at testing and improving high resolution models of the shelf edge, by carrying out detailed process studies in contrasting regions of the shelf edge of the NE Atlantic margin
• To develop a new parameterisation of shelf edge exchange processes suitable for regional-scale models, using improved resolution numerical, and new empirical models constrained by the observations
• To test the new parameterisations in a regional model in the context of making an assessment of inter-annual variability of ocean-shelf exchange.

Fieldwork

Three survey sites on the UK shelf edge have been selected for FASTNEt. These are a) the Celtic Sea shelf edge, b) Malin shelf and c) North Scotland shelf. Fieldwork is centred around two research cruises. The first, to the Celtic Sea, on RRS Discovery in June 2012. The second cruise visits the Malin shelf on RRS James Cook, during summer 2013. In addition to these dedicated cruises, opportunist cruise activity to the North Scotland shelf has been agreed with project partner Marine Scotland Science. Autonomous technologies will complement observations made during the cruises and provide knowledge of seasonal and inter-annual variability in exchange processes.

Instrumentation

Types of instruments/measurements:

• Gliders
• Autosub Long Range
• Drifter buoys
• Scanfish
• Microstructure profilers
• Moored CTD/CT loggers and ADCPs
• Shipboard measurements: CTD, underway, nutrients (and other discrete sampling), LADCP, ADCP.

Contacts

Data Activity or Cruise Information

Data Activity

FASTNEt inline mooring SE

The short term mooring SE inline was deployed and recovered during cruise RRS James Cook JC088 as part of the Fluxes Across the Sloping Topography of the North East Atlantic (FASTNEt) project.

Instruments deployed on the mooring

Key

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

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: JC088_SE

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.