Metadata Report for BODC Series Reference Number 1781302

• 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

Teledyne RDI's Workhorse Long Ranger ADCP

The Workhorse Long-Ranger acoustic doppler current profiler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented broadband signal (75 kHz) and a standard depth rating of 1500m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

The instrument comprises:

• An aluminium transducer head with four beams at 20^o from the vertical in a convex configuration, temperature sensor, electronic assemblies, fluxgate compass, pitch and roll sensors
• 4 x 28 D-cell alkaline battery packs
• 40 MB PC card internal memory (upgradeable to 440 MB)
• 1500m depth rated 6061 aluminium pressure case. End cap with wet material connector and dummy plug

UK-OSNAP Moored ADCP

This rig was deployed as part of the UK-OSNAP project as RTADCP1 at 57° 06.240'N, 9° 20.316'W at a depth of 746m.

The deployment consisted of a Teledyne RD Instruments 75KHz ADCP in a DeepWater Buoyancy AL-500 Trawl Resistant Bottom Mount (TRBM) with a non-recoverable concrete base. The AL-500 was fitted with a pair of Ixsea AR861 acoustic releases to provide redundancy in the event of individual failure. Recovery aids fitted were a Novatech Iridium beacon and a Novatech strobe, both pressure activated on surfacing.

Instruments deployed on the rig

UK-OSNAP Moored ADCP BODC data processing document

The Moored ADCP data were supplied to BODC as ascii files and converted to the BODC internal format.

During transfer the originator's variables were mapped to unique BODC parameter codes. The following table shows the parameter mapping.

Following transfer the data were screened using BODC in-house visualisation software. Suspect data values were assigned the appropriate BODC data quality flag. Missing data values, where present, were changed to the missing data value and assigned a BODC data quality flag

UK-OSNAP Mooring ADCP data processing document

This document outlines the procedures undertaken to process and quality assure ADCP data collected under the UK-OSNAP project.

Originators processing

The raw data were downloaded from the instrument and converted to Matlab format. Once in Matlab format the data is transferred into RDB format

Corrections

Once in RDB format the data are corrected for the following:

• Bin mapping - remaps bins with an actual speed of sound
• Launching and Recovery periods are removed
• Magnetic deviation

Data were visually inspected for out-lying data and instrument electrical spikes removed.

Project Information

UK - Overturning in the Subpolar North Atlantic Programme (UK-OSNAP) Programme

UK-OSNAP is part of an international collaboration to establish a transoceanic observing system in the subpolar North Atlantic. The aim is to quantify and understand the Subpolar Gyre's response to local and remote forcing of mass, heat and freshwater fluxes, within the conceptual framework of the Atlantic Meridional Overturning Circulation (AMOC).

UK-OSNAP is developing a new observing system to provide a continuous record of full-depth, trans-basin mass, heat, and freshwater fluxes. Combining these sustained measurements with innovative modelling techniques will enable the project to characterise the circulation and fluxes of the North Atlantic Subpolar Gyre.

UK-OSNAP is funded by the Natural Environment Research Council (NERC). The project is led by the National Oceanography Centre (NOC) with partners in the University of Liverpool, the University of Oxford and the Scottish Association for Marine Science (SAMS). It is a part of international OSNAP that is led by USA and includes 10 further partner groups in Canada, France, Germany, the Netherlands and China. The project involves fieldwork at sea and model studies.

The OSNAP observing system consists of two legs: one extending from southern Labrador to the southwestern tip of Greenland across the mouth of the Labrador Sea (OSNAP West), and the second from the southeastern tip of Greenland to Scotland (OSNAP East). The observing system also includes subsurface floats (OSNAP Floats) in order to trace the pathways of overflow waters in the basin and to assess the connectivity of currents crossing the OSNAP line.

NERC have added an extension to UK-OSNAP, until October 2024. This will result in the UK-OSNAP-Decade: 10 years of observing and understanding the overturning circulation in the subpolar North Atlantic (2014-2024).

Data Activity or Cruise Information

Data Activity

UK-OSNAP Moored ADCP

This rig was deployed as part of the "Overturning in the subpolar North Atlantic Programme" (OSNAP).

The DeepWater Buoyancy AL-500 Trawl Resistant Bottom Mount (TRBM) was fitted with a pair of Ixsea AR861 acoustic releases to provide redundancy in the event of individual failure. Recovery aids fitted were a Novatech Iridium beacon and a Novatech strobe, both pressure activated on surfacing.

The instruments deployed on the rig were as follows:

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

UK-OSNAP Mooring RTADCP1

Mooring RTADCP1 forms part of the OSNAP-East Transect. It was first deployed on 29^th October 2014 by the UK-OSNAP Community.

It is located at 57.10302°N, 9.33799°W where there is a water depth of 746m.

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: