Metadata Report for BODC Series Reference Number 1971463

• 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

UK-OSNAP Moored ADCP BODC Data Processing

The Teledyne RDI 300kHz ADCP data were supplied to BODC as ASCII files and converted to BODC internal format (QXF).

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 Moored ADCP Originator Data Processing

Sampling Strategy

During the RV Pelagia cruise PE400, downward looking Teledyne RDI Workhorse Sentinel 300kHz ADCPs were deployed on five NOC moorings (M1, M2, M3, M4 and M5). These moorings were recovered during the RRS Discovery cruise DY054.

Data Acquisition and Initial Processing

The data were downloaded from the instruments with metadata recorded, and were corrected for water depth and the magnetic declination. The data were then converted to RODB format and merged with the metadata file, and the launch and recovery periods removed from the data using WinADCP.

The final data processing did not create .edt files for bins that did not have any good data for the whole deployment. The processed data were supplied to BODC for banking.

Problems

Comparison with other instruments suggests that the pressure recorded by each ADCP is about 30db greater than expected. The first bin of data looks not to be useable. Good data appears to have been recorded in the following bins close to the instruments, but the quality decreases with increasing range and there is a noticeable reduction in range in the springtime, presumably due to a reduced number of scatterers in the water column.

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

OSNAP Moored Instrument M4 2015-2016

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

The rig was held down by a 780 kilogram anchor on the seabed at 2985 metres depth. It was kept erect by a series of syntactic floats.

The instruments deployed on the rig were as follows:

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

UK-OSNAP Mooring M4 (OM40)

Mooring M4 (called OM40 by the International OSNAP Community) forms part of the OSNAP-East Transect. It was first deployed on 8^th August 2014 by the UK-OSNAP Community.

It is located at 59.6478°N, 38.5672°W where there is a water depth of 2985m

Related Fixed Station activities are detailed in Appendix 2

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: OSNAP_NOC_M4_PE400_201507

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.

Appendix 2: UK-OSNAP Mooring M4 (OM40)

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.