Metadata Report for BODC Series Reference Number 2230540

• 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

Sea-Bird SBE 37-SMP MicroCAT

The SBE 37-SMP MicroCAT is a high accuracy conductivity and temperature recorder (pressure optional) with Serial interface, internal battery, non-volatile FLASH Memory and integral Pump. The Integral Pump runs for 1 second each time the MicroCAT samples, improving the conductivity response and giving improved anti-foul protection.

Designed for moorings and other long-duration, fixed-site deployments, MicroCATs have non-corroding titanium housings rated for operation to 7000 meters or pressure sensor full scale-range. Communication with the MicroCAT is over an internal, 3-wire, RS-232C link. The MicroCAT's aged and pressure-protected thermistor has a long history of exceptional accuracy and stability (typical drift is less than 0.002°C per year). Electrical isolation of the conductivity electronics eliminates any possibility of ground-loop noise.

Specifications

Further information can be found via the following link: Sea-Bird SBE 37-SMP MicroCAT Datasheet

Processing by BODC of Sea-Bird SBE 37 MicroCat SMP-CT CTD data: Ellet Array Moorings 2022 - 2024

The data was supplied to BODC via 25 .txt files (one for each sensor on each mooring) which were loaded into the BODC database using established BODC data banking procedures. A parameter mapping table is provided below:

The reformatted data were visualised using in-house software. Any suspect data were flagged, using the BODC quality control flags.

Processing by originator of Sea-Bird SBE 37 MicroCat SMP-CT CTD data: Ellet Array Moorings 2022 - 2024

Sampling Strategy

Three moorings were deployed during RRS James Cook cruise JC238 between 12nd July 2022 and 31st July 2022. 54 Sea-Bird SBE 37 MicroCat SMP-CT with optional pressure (submersible) CTD sensor series were deployed across the Ellet Array moorings on RRS James Cook cruise JC238. All microcats were cal-dipped prior to the deployment. Instruments showing a conductivity offset > 0.02 mS/cm were not deployed, and generally the scientific party selected instruments with an offset < 0.015 mS/cm wherever possible. The instruments were fitted with new batteries (SAFT 3.6 V Lithium AA cells), their clocks were sychronised with GPS time and set to sample every 1800 seconds. Endurance estimates from SeaBird's Deployment Endurance software were over 1200 days for all instruments.

Analytical Protocol

The Ellet Array moorings were recovered during RRS Discovery cruise DY181 between 3rd July - 28th July 2024. All 54 microcat instruments deployed across the Ellet Array were operational upon recovery and collecting data consistently after being deployed for 24 months. Most of the microcats reported a clock drift of less than 1 minute from UTC time, with some of the older instruments (serial numbers < 5000) showing larger offsets of up to 3.75 minutes. The raw data were converted to .cnv format in post-recovery processing, where no major issues were observed in the data. All microcats were cal-dipped post-deployment. The pressure, temperature and conductivity data was corrected for sensor drifts and/or offsets in post-processing using the data from post-recovery calibration dips alongside pre-deployment calibration dips carried out during deployment cruise JC238.

Further information can be found in the JC238 and DY181 cruise reports.

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

Ellett Array Moored Instruments RTWB1 2022-2024

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

The rig was held down by an 2200 kilogram anchor on the seabed at 1600 metres depth. It was kept erect by 40" syntactic float at 488 metres depth and a 31" syntactic float at 95 metres depth.

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/Ellett Array Mooring RTWB1 (OM55)

Mooring RTWB1 (called OM55 by the International OSNAP Community) forms part of the OSNAP-East Transect and, from 2018, the Ellett Array. It was first deployed on 17^th July 2014 by the UK-OSNAP Community.

It is located at 57.4707°N, 12.7050°W where there is a water depth of 1600m

Between 2014 and 2018 this mooring was funded by UK-OSNAP, from 2018 it was funded as part of the Ellett Array by CLASS (Climate Linked Atlantic Sector 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: RTWB1_07_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 RTWB1 (OM55)

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.