Metadata Report for BODC Series Reference Number 1797795

• 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

RRS James Clark Ross JR20120327 (JR254E, JR257, JR272A) Lowered Acoustic Doppler Current Profiler (LADCP): Data Quality Report

The originator noted data quality issues for Series Reference 1797875 (CTD Cast 21) where interference may have been caused by a change in altimeter (s/n 7742.163162) and for shallow casts deployed in Cumberland Bay Series Reference 1797918 to 1798055 (CTD Cast 26-38) possibly caused by ship board echosounders. Please use data with caution.

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

Teledyne RDI's Workhorse Monitor ADCP

The Workhorse Monitor acoustic doppler current profler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented four beam signal (300, 600 or 1200 kHz) and a standard depth rating of 200m or 600m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

RRS James Clark Ross JR20120327 (JR254E, JR257, JR272A) Lowered Acoustic Doppler Current Profiler (LADCP): BODC Processing

The LADCP data were converted from processed tab-delimited text files into BODC internal format using established procedures. The following table shows how the variables within the text files were mapped to appropriate BODC parameter codes:

All reformatted data were visualised using the in-house Edserplo software and screened for suspect and missing data.

Please note that raw LADCP files and processed files using University of Hawaii's LADCP processing software are available on request.

RRS James Clark Ross JR20120327 (JR254E, JR257, JR272A) Lowered Acoustic Doppler Current Profiler (LADCP): Originator's Processing

Sampling Strategy

Lowered Acoustic Doppler Current Profiler (LADCP) data were collected on-board cruise JR20120327. The Teledyne RD Instruments Workhorse Monitor LADCP was installed in a downward looking configuration on the CTD rosette deployed on all 38 CTD cast, however failed for Cast 25 therefore no data file was produced.

Data Processing

The processing steps used by the originator were based on those used for cruises JR139 and JR239. Processing was performed using software from the University of Hawaii (UH) (2008 version) and from Lamont-Doherty Earth Observatory (LDEO) (version 7). The UH software uses the shear from the ADCP profiles to reconstruct a full velocity profile, while the LDEO software uses a matrix inversion technique to optimize stitching the profiles together, reconstructing the CTD package drift in the process.

The processing steps applied are outlined below; please refer to JR20120327 (JR272A)cruise report for further details.

• At the start of each cast, a test script was run on the ADCP to check that everything was working well.
• A BAS standard command file was run. This file should be adapted where necessary for future cruises. Please see the cruise report for an example of the file.
• Raw data and transcript files from each deployment, were downloaded to a laptop in the chemistry lab, and backed up before being saved on the ships directory.
• Navigation files were created. Input: data streams; output .mat files. Then the edexec_startall' script was run to create all of the processed ascii data files within the current directory. m_setup and make_sm were run to create sm.mat.
• CTD files were created. Input: 1Hz processed NetCDF files; output: ASCII files. The linkctd script was modified to create links to the raw files. mk_ctdfile(NNN) script was run in Matlab for each CTD cast.
• Links were created to raw LADCP files by running the linkscript.
• Files were processed using UH software in Matlab. Specific code used is outlined in the cruise report.
• Checks were made to ensure CTDs and LADCP casts were aligned correctly using an algorithm.
• Files were then processed using LDEO software in Matlab. Specific code used is outlined in the cruise report.

The raw LADCP data files and processed text files from UH and LDEO software were submitted to BODC.

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

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

WOCE Hydrographic Programme Section A23

This section is part of the One-Time Survey of World Ocean Circulation Experiment (WOCE) designated A23. A hydrographic section from Antarctica to Brazil in the South West Atlantica. A full suite of physical, chemical, biological, meterological and tracer measurements were made. During WOCE in 1995 (James Clark Ross, cruise JR10) the A23 section area encompassed 20-70° S and 20-70° S. Part of this A23 section located in the eastern Scotia Sea has been repeated by theALBATROSS project (James Clark Ross, cruise JR40) in 1999, theUS CLIVAR repeat hydrography/CO₂ in 2005 (R/V Ronald H. Brown, cruise A16S_2005a) under theCLIVAR/Carbon repeat hydrography program. From 2010 onwards the British Antarctic Survey has conducted annual cruises to survey the southern portion of this section, from the Weddell Sea to South Georgia. A comprehensive list of cruises is included below the map.

From

History of Occupations at Section A23

Related Fixed Station activities are detailed in Appendix 1

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: WOCE section A23

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.