Metadata Report for BODC Series Reference Number 2295666

• 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

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

BODC Processing of Cruise JC238 Sea-Bird SBE 37 MicroCAT data from Ellett Array Icelandic Basin Moorings IB3, IB4 and IB5

The Sea-Bird SBE 37 MicroCAT 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. Additionally, the start of data files have been trimmed to remove null data cycles where this was present across all channels during mooring deployment.

Originator's Processing of Cruise JC238 Sea-Bird SBE 37 MicroCAT data from Ellett Array Icelandic Basin Moorings IB3, IB4 and IB5

Sampling Strategy

During RRS James Cook cruise JC238, 12 Sea-Bird SBE 37 SMP-CTP MicroCATs were deployed at the IB3 site, 12 at the IB4 site and 7 at the IB5 site. Additionally, 4 Sea-Bird SBE 37 SMP-CTP-ODO MicroCATs were deployed at the IB4 site. The MicroCATs were fitted with new batteries (SAFT 3.6V Lithium AA cells) and their clocks were synchronised with GPS time. All the SMP-CTP MicroCATs were set to sample every 1800 seconds, while the SMP-CTP-ODO MicroCATs sampled either every 3600 or 4500 seconds. All MicroCATs were set to record pressure, temperature and conductivity, while the SMP-CTP-ODO MicroCATs also recorded oxygen. All instruments were recovered during RRS Discovery cruise DY181.

Data Acquisition, Calibration and Initial Processing

All MicroCATs were cal-dipped prior to deployment and post recovery, and the data were corrected for sensor drift and offsets using all these measurements.

After recovery, the instruments deployed in the top 100 to 200m and those just above the bottom showed quite significant biofouling, however none near the cell intake and exhaust, which were fitted with antifoulant devices. SMP-CTP MicroCAT S/N 11139 (IB3 1500m) was recovered with an obstruction in the CT cell exhaust, thought to be a degraded antifoulant. However the data from this MicroCAT are unaffected.

Most of the SMP-CTP MicroCATs reported a clock drift of less than 1 minute from UTC time, with some of the older instruments (serial numbers <5000) showing a larger offset of up to 3.75 minutes. The SMP-CTP-ODO MicroCATs reported a clock drift of less than 1 minute from UTC time, except for S/N 12908 (IB4 350m) which had drifted by -10 minutes 45 seconds.

The raw data were converted to cnv in SBEDataProcessing (DatCnv module) for SBE37's v>=3.0, and in SeaTerm using the 'Convert' tool for SBE37's v<=3.0. All instruments recorded data for the full deployment period and no major issues were observed in the data. The processed data were supplied to BODC for banking. Dissolved oxygen data was not included and will be ingested separately by BODC.

Deployment Cruise Information

Further information can be found in the deployment cruise summary report for RRS James Cook JC238

Recovery Cruise Information

Further information can be found in the recovery cruise summary report for RRS Discovery DY181

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). UK-OSNAP Decade forms part of the wider UK-OSNAP programme. Although supported through separate funding streams, including the Collective Funds 'Changing North Atlantic' grant, OSNAP decade (NE/T00858X/1), is considered a continuation of the core programme. In line with this, activities and associated data are grouped under UK-OSNAP, with funding details recorded here rather than as a separate project.

Data Activity or Cruise Information

Data Activity

Ellett Array Moored Instruments IB4 2022-2024

This rig was deployed as part of the Iceland Basin Array.

The rig was held down by a 1900 kilogram anchor on the seabed at 2919 metres depth. It was kept erect by 44" syntactic float at 75 metres depth and 2 glass spheres at 45 metres depth.

The instruments deployed on the rig were as follows:

Issues with mooring and sensors

The oxygen sensor failed at the start of the cal-dip on MicroCAT SMP-CTP-ODO S/N 12908 (349 m). Temperature and conductivity data are unaffected.
The Nortek Aquadopp S/N 11021 (1496 m) was found to be flooded (water ingress at bulkhead connector) and the data could not be retrieved.
The downward looking RDI WorkHorse 300kHz ADCP S/N 24589 was recovered flooded with its pressure sensor missing. No data were recovered.

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/Ellett Array Mooring IB4 (OM54)

Mooring IB4 forms part of the OSNAP-East Transect and of the Ellett Array. It was first deployed in summer 2014 by the University of Miami. The mooring management and maintenance switched to the UK-OSNAP Community in July 2018.

It is located at the nominal location 58.00°N, 21.14°W in a water depth of 2920 m.

The mooring has been funded as part of the Ellett Array by UK-OSNAP (UK - Overturning in the Subpolar North Atlantic), CLASS (Climate Linked Atlantic Sector Science) and AtlantiS (Atlantic Climate and Environment Strategic Science).

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: IB4_03_2022

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/Ellett Array Mooring IB4 (OM54)

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.