Metadata Report for BODC Series Reference Number 2052084

• 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

JR16005 VMADCP Quality Control Report

Six large gaps made up of entirely null cycles were identified in the data throughout the cruise. These null cycles have been removed:

• 19 March 2017 20:44:37 hours to 20 March 2017 10:48:48 hours
• 20 March 2017 20:00:46 hours to 20 March 2017 22:13:07 hours
• 30 March 2017 02:58:49 hours to 31 March 2017 03:12:49 hours
• 01 April 2017 03:40:47 hours to 02 April 2017 03:14:48 hours
• 07 April 2017 03:28:48 hours to 08 April 2017 03:00:48 hours
• 28 April 2017 07:30:48 hours to 29 April 2017 10:08:47 hours

In addition to these gaps, there are shorter periods of null data. For these shorter periods, sometimes only 1 cycle long, the time channel value has been set based on the cycles being every 120 seconds.

Data is very intermittent on the 20^th of March.

LCEWAS01 & LCNSAS01

LERRAS01

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

RD Instruments- Ocean Surveyor 75kHz Vessel mounted ADCP.

¹ Ranges at 1 to 5 knots ship speed are typical and vary with situation.
² Single-ping standard deviation.
³ User's choice of depth cell size is not limited to the typical values specified.

Profile Parameters

• Velocity long-term accuracy (typical): ±1.0%, ±0.5cm/s
• Velocity range: -5 to 9m/s
• # of depth cells: 1 - 128
• Max ping rate: 0.7

Bottom Track

Maximum altitude (precision <2cm/s): 950m

Echo Intensity Profile

Dynamic range: 80dB
Precision: ±1.5dB

Transducer and Hardware

Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W

Standard Sensors

Temperature (mounted on transducer)

• Range: -5° to 45°C
• Precision: ±0.1°C
• Resolution: 0.03°

Environmental

Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*

*later instruments have greater range.

Web Page

Further details can be found on the manufacturer's website or in the specification sheet

Processing by BODC of JR16005 cruise Vessel Mounted ADCP data

The data arrived at BODC as a matlab file (.mat) which contained matrices of the various variables collected from the 75kHz ship mounted ADCP on JR16005. The data were reformatted to BODC's internal NetCDF format. The following table shows the mapping of original variables to the appropriate BODC parameter codes:

The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, and missing data were set to an appropriate value and flagged.

Processing by Originator of JR16005 cruise Vessel Mounted ADCP data

A Teledyne RDI Ocean Surveyor 75 kHz mounted on the RRS James Clark Ross was used to collect ADCP data throughout the JR16005 cruise. The cruise occurred between the 17^th of March 2017 and the 8^th of May 2017 in the regions of Orkney Passage, Scotia Sea.

Data were recorded using VmDas software.

ADCP setup

The instrument's ping rate was set independently from the SIMRAD Synchronization Unit, which means that it has its own internal ping rate. The tranducer misalignment angle was set to 60.08°.

The instrument was set in "narrowband" mode.

Data Processing

The data were post-processed through a set of Matlab scripts to quality check the data and calibrate the ADCP misalignment angle and amplitude factors.

The performance of the ADCP was seen to be heavily weather dependent. In times of low windspeeds and relatively calm waters percentage of good values exceeded 50% at depths below 500 m, however at times of rough weather the performance deteriorated, and data quality issues prevented processing.

Additional information can be found in the JR16005 cruise report:

Naveira-Garabato, A. et al., 2017 RRS James Cook Cruise JR16005, 17 Mar - 08 May 2017. The Dynamics of the Orkney Passage Outflow (DynOPO). Southampton, UK: National Oceanography Centre, Southampton, 222pp., National Oceanography Centre Cruise Report, No. 47. https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/jr16005.pdf

Project Information

Dynamics of Orkney Passage Outflow (DynOPO)

DynOPO is a five year research project that aims to understand how Antarctic Bottom Water is exported and modified through the Orkney Passage, the overflow's controlling dynamics, and its downstream impact on the Atlantic Ocean abyss.

Introduction

Mooring data collected for the DynOPO project are a component of a long term time series, in association with the Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) project, led by Emily Shuckburgh (British Antarctic Survey) since 2016. The time series originally started out as part of the British Antarctic Survey's Long-Term Monitoring and Survey (LTMS) programme. Moorings were deployed on RRS James Clark Ross cruise JR20150309 (JR310 and JR272D) which ran from 09 March to 14 April 2015. RRS James Clark Ross cruise JR16005 ran from 17 March to 08 May 2017 and was the primary fieldwork element of the DynOPO project. The cruise had two main goals: (1) to conduct measurements of the hydrographic properties, velocity and turbulent processes of the Antarctic Bottom Water outflow along its pathway through the Orkney Passage region; and (2) to turn around a set of long-term moorings deployed in the area by British Antarctic Survey (BAS) and Lamont-Doherty Earth Observatory (LDEO) scientists, including recovery of additional instruments on some of the moorings deployed by JR20150309.

Project Collaborators

The project was led by the University of Southampton, and is an international collaboration with;

• UK: British Antarctic Survey (BAS), UK Meteorological Office, University of East Anglia and Newcastle University;
• Europe: University of Gothenburg (Sweden), University of Paris 6 (France);
• Australia: University of Tasmania;
• US: Lamont Doherty Earth Observatory, Woods Hole Oceanographic Institute, NOAA, University of California, Washington State University and Princeton University

Funding

The project was funded by the Natural Environment Research Council and ran from March 2015 to November 2018.

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

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: