Metadata Report for BODC Series Reference Number 1840310

• 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-SM MicroCAT

The SBE 37-SM MicroCAT is a high accuracy conductivity and temperature recorder (pressure optional). Designed for moorings and other long-duration, fixed-site deployments, MicroCATs have non-corroding titanium housings rated for operation to 7000 metres 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° 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: SBE 37-SM MicroCAT Datasheet

BODC Data Processing

Data Processing

The data arrived at BODC as individual .mat files containing data collected on moorings OP1, OP2, OP3, OP4, OP5, OP6, OP7, CI1 and CI2. They were submitted as part of an accession which includes data from several mooring instruments e.g. Aquadopp, RCM8, RCM11, RBR, SBE37 and SBE39.

Reformatting

Parameters in the originator's files were reformatted into an internal file format using BODC standard procedures.

The following table lists all the parameters included in the internal format files, showing how the originator's variables as named in the matlab files were mapped to appropriate BODC parameter codes.

No derived parameters were calculated by BODC. Please note that not all parameters are present in all files.

Screening

Quality control flags were automatically added to data outside the expected parameter specific range during the reformatting process. All parameters were then visualised and screened using in house software, and any improbable or missing data point was assigned a quality control flag.

Originator's Data processing

Sampling strategy

Sampling was carried out as part of the BAS LTMS (British Antarctic Survey Long Term Monitoring and Survey) until 2016. From 2016 onwards the moorings are split between 'The Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA)' project and 'Dynamics of the Orkney Passage Outflow (DynOPO)' project.

The projects involve the deployment of moorings CI1, CI2, OP1, OP2, OP3, OP4, OP5, OP6 and OP7 in the Southern Ocean, situated north of Coronation Island and the Orkney Passage in the Weddell and Scotia Sea.

Moorings CI1 and CI2 were deployed from 2005 to 2007 and moorings OP1, OP2, OP3, OP4, OP5 and OP6 have been continuously maintained since 2007 with the addition of OP7 in 2015.

SBE 37 and SBE39 instruments were deployed on the moorings. Data have been collected at variable intervals: 5 minutes interval on the Coronation Island moorings, 7.5 minute interval on the instruments deployed on OP2 and OP3 in 2007 and 15 minute intervals since then. Gaps in the series may be caused by either instruments not being recovered, or data not being collected due to instrument malfunction.

Data processing

Little information is known with regards to the exact details of the calibrations carried out on the mooring data. Data processing, visualisation and calibration were carried out through the use of scripts for Matlab version R2014b produced and ran by the originator.

An offset has been applied some of the channels. The values for each deployment/instrument/channel combination are shown in the table below:

Several instruments deployed in the 2013/15 period show evidence of knock-down but the data colleaction seems to be unnafected. According to the originator some of the moorings were deployed with insufficient buyoancy which caused the knockdowns. These instances are especially visible on moorings OP1 and OP2, Series Reference number 1840205, 1840229, 1840254, 1840266 and 1840278

Several instruments deployed in the 2015/17 period did not have a pressure sensor and used inferred pressure calculated from the closest neigbhouring pressure sensor. This includes five SBE39 instruments (s/n 4413, 4716, 4713, 4418 and 4409) and one SBE37 instrument (s/n 8267).

Several instruments deployed in the 2017/19 period did not have a pressure sensor, therefore no pressure channel was transferred with the data and only a nominal depth is used in the metadata. This includes all SBE39 instruments (s/n 4413, 4409, 0083, 4713, 4418 and 4716) and one SBE37 instrument (s/n 8267).

Project Information

BAS Long Term Monitoring and Survey

Introduction

The Long Term Monitoring and Survey project (LTMS) has been running since the British Antarctic Survey (BAS) was created. This project is one of the BAS core projects, with several groups of scientists collecting various types of data e.g biological, geological, atmospheric, among others.

Data collection is achievable through a wide scope of instruments and platforms, e.g. the Antarctic research stations, autonomous instrument platforms deployed on or from BAS research ships, BAS aircrafts, satellite remote sensing and others.

Scientific Objectives

This project was implemented in order to measure change and variability in the Earth system. Its long term duration allows for the monitoring of processes that could be missed in shorter term studies and experiments. The data collected is also used to check and improve the reliability of models used to stimulate and predict the behavior of the Earth system.

The main objectives are:

• Topographic survey
• Geosciences survey
• Biological survey and monitoring
• Atmospheric and oceanographic monitoring

Data Availability

The data sets obtained through this project are available to the academic community.

Data Activity or Cruise Information

Data Activity

Orkney Passage mooring 4 (OP4)

The mooring was deployed at the following positions:

The mooring was deployed on the Orkney Passage on cruise JR20130317 (JR252B, JR272B, JR273A, JR281, UKD-4) on 03 April 2013 and recovery was done on cruise JR20150309 (JR272D, JR310) on 21 March 2015.

The table below lists the instruments deployed on this mooring:

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

Orkney Passage OP4 site

Site OP4 is part of the Orkney Passage mooring array which is an activity covered by the Long Term Monitoring and Survey British Antarctic Survey's (BAS) programme. The data collection is the result of an ongoing collaboration between BAS and the Lamont-Doherty Earth Observatory (LDEO).

This site has been occupied since 2011 but throughout the years it has been moved. The recovery/deployment history, including position details, is presented below:

Detailed information for each deployment can be accessed from the OP4 Data Activity document.

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: OP4

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: Orkney Passage OP4

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.