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Metadata Report for BODC Series Reference Number 1839787


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI Workhorse Sentinel-300 ADCP  current profilers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Yvonne Firing
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) NERC-CONICYT ICEBERGS
 

Data Identifiers

Originator's Identifier 006DL002
BODC Series Reference 1839787
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2017-11-24 15:06
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 5.0 metres
 

Spatial Co-ordinates

Latitude 62.21761 S ( 62° 13.1' S )
Longitude 58.78918 W ( 58° 47.4' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 5.0 m
Maximum Sensor or Sampling Depth 85.0 m
Minimum Sensor or Sampling Height 14.0 m
Maximum Sensor or Sampling Height 94.0 m
Sea Floor Depth 99.0 m
Sea Floor Depth Source BRIDGE
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
ACYCAA011DimensionlessSequence number
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
LCEWLW011Centimetres per secondEastward velocity of water current (Eulerian measurement) in the water body by lowered acoustic doppler current profiler (ADCP)
LCNSLW011Centimetres per secondNorthward velocity of water current (Eulerian measurement) in the water body by lowered acoustic doppler current profiler (ADCP)

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database

LADCP data from cruise JR17001 Quality Report

Screening and Quality Control

During BODC quality control, data were screened using in house visualisation software. The data were screened where any obvious outliers were looked at in closer detail but it was not deemed that any points were anomalous.


Data Access Policy

Data access conditions (generic)

Access to these data is currently restricted and the data may not be released by BODC without obtaining specific permission from the data originator.


Narrative Documents

RD Instruments 300kHz Workhorse Sentinel Acoustic Doppler Current Profiler

Specifications

Water velocity measurements relative to the ADCP
Maximum velocity 10 m.s-1
Standard deviation 130, 45, 25, 12, 5 mm.s-1 for depth cell sizes of 1, 2, 4, 8, 16 m, respectively
Minimum time between pings 0.07 s
Maximum profiling range* 110, 120, 130, 150, 165 m for depth cell sizes of 1, 2, 4, 8, 16 m, respectively
Minimum range to start of first depth cell 3 m
Number of depth cells 1 - 128 cells
Depth cell size 1 - 16 cm
Echo Intensity measurements
Uncertainty ± 1.5 dB
Sampling Uses same depth cells and time intervals as velocity
Sensors
Water level resolution 0.25 m
Water level accuracy ± 5 m over 0-200 m depth
Temperature range -5°C to + 45°C
Temperature uncertainty ± 0.4°C
Tilt range ± 20°
Tilt uncertainty ± 2°
Compass uncertainty ± 5° at 60° magnetic dip angle
Compass maximum tilt 20°
Physical and Environmental
Maximum depth 200 m
Operating temperature -5°C to 60°C
Storage Temperature -5°C to 80°C

The manufacturer's specification document can be found here

Instrument Description for JR17001 CTD

CTD Unit and Auxiliary Sensors

The CTD unit comprised a Sea-Bird Electronics (SBE) 9plus underwater unit, an SBE 11 plus deck unit, a 24-way SBE 32 carousel and 24 Niskin bottles; all of which were mounted on a stainless steel 24-way CTD frame. Attached to the CTD were two SBE 3P temperature sensors, two SBE 4C conductivity sensors, one SBE 43 dissolved oxygen sensor, one QCP2350 PAR sensor, one CTG Aquatracka MKIII fluorometer, one WetLabs C-Star transmissometer, one Tritech Altimeter, one SBE35 temperature sensor and a RDI LADCP.

Sensor unit Model Serial number Full specification
CTD underwater unit SBE 9plus 0707 SBE 9plus
CTD deck unit SBE 11plus 0458 -
Carousel SBE 32 - 24 Position Pylon 0636 SBE 32
Temperature sensor SBE 3P 2705 SBE 03P
Temperature sensor SBE 3P 5042 SBE 03P
Conductivity sensor SBE 4C 3488 SBE 04C
Conductivity sensor SBE 4C 2248* SBE 04C
Dissolved oxygen sensor SBE 43 0242 SBE 43
Altimeter Tritech PA-200 10127 Tritech PA-200
Irradiance sensor Biospherical QCP2350 PAR 70636 Biospherical QCP PAR sensor
Fluorometer Chelsea MKIII Aquatracka 09-7324-001 Chelsea MKII Aquatracka
Transmissometer WetLabs C-Star 396 WetLabs C-Star
Temperature sensor (Independent) SBE 35 0024 SBE 35
LADCP RDI Workhorse 300 kHz 15060** LADCP

* The secondary conductivity sensor was replaced during the cruise due to the output of the first sensor being spikey. The serial number of the first sensor was 2248 and the serial number of the second sensor was 2255.

** The LADCP was replaced during the cruise due to excessive file fragmentation. The LADCP was replaced by RDI Workhorse 300 kHz serial number 14897.

BODC Data Processing of LADCP data from cruise JR17001

Data Processing

The LADCP data from cruise JR17001 were processed and submitted to BODC in .mat format. The files were subsequently archived and transferred to BODC internal format using standard BODC procedures. The variables provided in the files were mapped to BODC parameter codes as follows:

Originator's Variable Originator's Units BODC Parameter Code BODC Units Comment
dr.z m ADEPZZ01 m -
dr.u m s-1 LCEWLW01 cm s-1 Conversion of *100 applied.
dr.v m s-1 LCNSLW01 cm s-1 Conversion of *100 applied.

Screening

Post transfer analysis and crosschecks were applied according to BODC procedures. This involved the screening of data using BODC's in house visualisation software where any anomalous data were flagged but not removed.

Originator Data Processing of LADCP data from cruise JR17001

Sampling Strategy

A total of 44 LADCP casts were performed during JR17001 with 34 of these casts completed as part of the ORCHESTRA programme and the remaining 10 casts completed for the NERC-CONICYT ICEBERGS programme. 20 of the ORCHESTRA casts surveyed the SR1b line. A 330 kHz Workhorse lowered acoustic Doppler current profiler (LADCP) was fitted in a downward looking position on the CTD rosette for all casts. The LADCP was configured to sample in 25 x 8 m bins and data were collected in beam coordinates and rotated to earth coordinates during data processing.

Data Processing

The LADCP was connected to a charger and to the CTD computer via a serial cable. Using the CTD computer, programming prior to each station was completed and the data were downloaded after each cast. This was done using BBTalk. The downloaded data were then copied to the network data drive and processed with the LDEO IX software. During processing, the ship's navigation file and CTD pressure streams were incorporated to constrain the solution for earth-relative velocity from the measured instrument-relative velocity.

Further information on the LADCP processing can be found in sections 12.2.5 and 15.3. b) of the cruise report.

Data Submission

Data from 42 of the 44 casts were submitted to BODC.


Project Information

Impacts of deglaciation on benthic marine ecosystems in Antarctica

Impacts of deglaciation on benthic marine ecosystems in Antarctica (ICEBERGS) is one of three NERC-CONICYT joint funded projects running for three years from 2017 to 2020. The aim of the programme is to investigate the impacts of physical disturbance arising from climate-warming induced deglaciation on benthic communities around the West Antarctic Peninsula.

Participants

There are four research institutions involved in the project:

  • University of Bangor
  • University of Exeter
  • Universidad Católica de la Santísima Concepción
  • British Antarctic Survey (BAS)

Research Details

In order to meet the aim of the project, the ICEBERGS consortium produced six objectives:

  • Monitoring glacier retreat over time and scour intensity on the adjacent seabed.
  • Determine the benthic assemblage structure from localities with different perturbation levels.
  • Evaluate nutritional and reproductive conditions of adults.
  • Analyse growth rates from bivalve/gastropod shells and bryozoan populations with different perturbation levels.
  • Develop reconstructions of physical disturbance due to iceberg discharge from growth patterns present in the carbonate structure of the shells of marine molluscs.
  • Estimate the effect of marine glacier discharge and iceberg scouring on the genetic diversity and connectivity of marine invertebrate populations and the role of dispersal potential.

Fieldwork and Data Collection

The fieldwork for the project consists of research cruises along the west Antarctic Peninsula across three field seasons on board the RRS James Clark Ross. Three sites (Marine Cove, William Glacier and Sheldon Glacier) were selected for the fieldwork using available bathymetry and glacier retreat data. The fieldwork covers physical oceanography, marine geology, habitat mapping, community structure and seabed sediments and consists of CTD deployments, multi-beam swath bathymetry surveys, TOPAS sub-bottom profiling, shallow underwater camera system deployments, plankton net deployments, Agassiz trawls, Hamon grabs and multi-corer deployments.


Data Activity or Cruise Information

Cruise

Cruise Name JR17001 (ORCHESTRA)
Departure Date 2017-11-21
Arrival Date 2017-12-21
Principal Scientist(s)Alexander Brearley (British Antarctic Survey), David Barnes (British Antarctic Survey), Yvonne L Firing (National Oceanography Centre, Southampton)
Ship RRS James Clark Ross

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:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain
Q value below limit of quantification