Metadata Report for BODC Series Reference Number 1789200

• 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

Sea-Bird SBE 37-IMP MicroCAT

The SBE 37-IMP MicroCAT is a high accuracy conductivity and temperature recorder (pressure optional) with a built in Inductive Modem and integral Pump. 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.

The Inductive Modem provides reliable, low-cost, real-time data transmission. The Integral Pump runs for 1 second each time the MicroCAT samples, improving the conductivity response and giving improved anti-foul protection.

Communication with the MicroCAT is via a Surface Inductive Modem (SIM) to a computer or data logger. Commands and data are transmitted half-duplex between the SIM and the MicroCAT using DPSK (differential-phase-shift-keyed) telemetry. As a safe guard, the MicroCAT simultaneously backs up the data in its non-volatile internal memory as well as transmitting the data via telemetry.

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-IMP MicroCAT Datasheet

BODC Processing

The 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.

Originator's Data Processing

Sampling strategy

Data were collected from multiple SBE 37 MicroCATs fitted on three moorings across the Rockall Trough. Details are displayed in the table below.

The moorings were deployed to the seabed from an acoustic release as part of cruise PE399. The MicroCATs were fixed at various depths on the mooring to collect measurements of pressure, temperature and conductivity every 30 minutes. They were recovered as part of cruise DY053.

Data processing

The MicroCATs were set up using SeaBird's SeaTerm V2 software and data were downloaded in ASCII and .cnv format. The raw data files were converted into standard RDB format. The data files were then trimmed to remove the launching and recovery period and offsets were applied before submitting to BODC.

It was observed that some MicroCATs had large offsets in temperature of conductivity compared to the CTD data, see the cruise report for further information.

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 EB1 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 1700 kilogram anchor on the seabed at 1800 metres depth. The rig was kept erect by a 40" syntactic float at 490 metres depth and a 31" syntactic float at 240 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 RTEB1 (OM57)

Mooring RTEB1 (called OM57 by the International OSNAP Community) forms part of the OSNAP-East Transect and, from 2018, the Ellett Array. It was first deployed on 18^th July 2014 by the UK-OSNAP Community.

It is located at 57.0993°N, 9.5480°W where there is a water depth of 1975m

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: RTEB1_02_2015

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 RTEB1 (OM57)

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.