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Metadata Report for BODC Series Reference Number 1758796


Metadata Summary

Data Description

Data Category Hydrography time series at depth
Instrument Type
NameCategories
Rockland Scientific Vertical Microstructure Profiler (VMP) 2000  microstructure sensors
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Alex Forryan
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Ice Sheet Stability (iSTAR) Programme
Ocean2ice (iSTAR A)
 

Data Identifiers

Originator's Identifier ISTAR_VMP_STATION047_36
BODC Series Reference 1758796
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2014-02-14 03:04
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 74.88993 S ( 74° 53.4' S )
Longitude 101.30495 W ( 101° 18.3' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 0.25 m
Maximum Sensor or Sampling Depth 837.24 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
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
EPSIPM011Watts per kilogramLog10 turbulent kinetic energy dissipation {epsilon} per unit mass of the water body by turbulence profiler shear sensor
PRESPR011DecibarsPressure (spatial coordinate) exerted by the water body by profiling pressure sensor and correction to read zero at sea level
PSALPR011DimensionlessPractical salinity of the water body by conductivity cell and computation using UNESCO 1983 algorithm
TDSSFT011Degrees Celsius squared per secondLog10 temperature dissipation rate in the water body by turbulence profiler fast temperature sensor
TEMPPR011Degrees CelsiusTemperature of the water body

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

Quality report - iSTAR VMP

Despite the challenging environment the data generally appear to be of a good quality. The cruise report included some notes about the data processing which have been used to support quality control at BODC. Some suspect data have been identified and flagged by BODC. Below is a summary of some of the originator's quality comments and significant BODC flagging decisions. Full originator's notes can be found in the cruise report.

Station Cast Originator's comment from cruise report BODC QC
3 1 First station in the ice. Ship stationary. Cable snag at ~150 db, profiler halted. Ran out of cable at 1100 db. Started pulling back slowly. Stuck in ice flow on way up at 1640 db. Shear 2 still a bit noisy,cleaned and dried probe again. No QC flags applied to data but data should be used with caution.
6 1 SBT appears to be blocked for a couple of hundred meters, ~200 db. Clears OK and upcast is fine. Quality control flags applied to salinity for surface half of cast. Temperature data looks OK but should be used with caution.
33 1 SBC reading high (near air values) for most of cast. May have been blocked (frozen), clears above 800 db on upcast and starts to read normal range. Salinity data flagged throughout profile as reading very fresh.
56 1 No comment. Salinity flagged for shallowest half of profile as appears to be very fresh and no corresponding signal in temperature parameter.
62 1 No comment Salinity flagged for shallowest half of profile as appears to be very fresh and no corresponding signal in temperature parameter.
63 1 No comment A few shallow cycles have been flagged in temperature and salinity parameters.

In addition some spikes were flagged by BODC in temperature, salinity and thermal dissipation variables.


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

BODC Processing - iSTAR VMP data

Data were received by BODC in Matlab files, with one file containing all data from the iSTAR VMP deployments. The data were reformatted to QXF (a NetCDF file format) by in house software. A separate QXF file was created for data from each deployment. Metadata were also extracted from the originator's file and used to populate the BODC database.

The following tables shows how the variables within the files were mapped to appropriate BODC parameter codes:

Originator's parameter name Origintator's units Description BODC Parameter Code BODC Units Comments
P (pressure) Decibars Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level PRESPR01 Decibars  
Td (temperature) Degrees Celsius Temperature of the water body TEMPPR01 Degrees Celsius  
Sd (Salinity) PSU Practical salinity of the water body by computation using UNESCO 1983 algorithm PSALZZXX Dimensionless  
Eps (turbulent kinetic energy dissipation) Watts per kilogram Log10 turbulent kinetic energy dissipation {epsilon} per unit mass of the water body by turbulence profiler shear sensor EPSIPM01 Watts per kilogram Conversion of Log10 applied
Chi (temperature dissipation) Degrees Celsius squared per second Log10 temperature dissipation rate in the water body by turbulence profiler fast temperature sensor TDSSFT01 Degrees Celsius squared per second Conversion of Log10 applied

Following transfer to QXF, the data were quality controlled using BODC's in-house visualisation software.

Originator's processing - iSTAR VMP data

Data collection

A Rockland Scientific International tethered VMP-2000 (a microstructure profiler) was deployed on iSTAR cruise RRS James Clark Ross JR20140126 in the Amundsen Sea. The data were collected for the Ocean2ice (iSTAR A) project which is part of the Natural Environment Research Council funded iSTAR programme.

139 microstructure profiles were collected in total recording pressure, temperature, salinity, turbulent kinetic energy dissipation and thermal dissipation data. 54 of the profiles were sampled alongside CTD casts whilst a further 85 profile were sampled as part of five "tow-yos".

For more information about the VMP deployments and data collection see the cruise report

Data processing

The data have been processed by the originator and calibrations have been applied following quality control. This processing is fully documentation in the VMP section of the cruise report

The Vertical Microstructure Profiler (VMP) collected data in challenging conditions during RRS James Clark Ross cruise JR20140126 with air temperatures reported between -8 °C and -13 °C common. The originator reports in the cruise report that there were occasions where the CTD froze during transportation from the lab to deck on ship. This was resolved by injecting warm water in to the CTD tube before transportation.


Project Information

The Ice Sheet Stability (iSTAR) programme

Background and objectives

The iSTAR programme aims to measure the rate that ice is being lost from the West Antarctic ice sheet, and to improve our understanding of what might be driving this loss how it is changing over time. The rate of loss of water from ice in glaciers in the Antarctic (and Greenland) is more than the amount of water being deposited in these areas by precipitation. This has changed our understanding of these systems and the rate of ice loss is a matter of interest for sea level and climate research. Improving our understanding of the processes and impacts of changes to these systems is vital for better predictions for sea level rise in the future and will feed in to climate research. This programme combines scientific research of glaciers and the surrounding ocean environment (including how they impact each other). Research about the oceans was focused on the Amundsen Sea Sector of West Antarctica with instruments deployed from the research ship RRS James Clark Ross. Research about the ice was focused on Pine Island Glacier, Thwaites Glacier and Union Glacier with measurements taken during two expeditions across the ice. This programme was funded by the Natural Environment Research Council (NERC)

The programme is split in to four projects:

Ocean2ice: Processes and variability of ocean heat transport toward ice shelves in the Amundsen Sea Embayment (iSTAR A)

Ocean under ice: Ocean circulation and melting beneath the ice shelves of the south-eastern Amundsen Sea (iSTAR B)

Dynamic ice: Dynamical control on the response of Pine Island Glacier (iSTAR C)

Ice loss: The contribution to sea-level rise of the Amundsen Sea sector of Antarctica (iSTAR D)

Participants

The iSTAR research programme is managed by British Antarctic Survey (BAS) on behalf of NERC. Operational support, in the form of logistics planning and infrastructure, and Communication and Knowledge Exchange support are provided by BAS. There are four science projects and participants in these projects represent the following organisations:

  • British Antarctic Survey
  • National Oceanography Centre
  • Newcastle University
  • Scott Polar Research Institute
  • University College London
  • University of Bristol
  • University of East Anglia
  • University of Edinburgh
  • University of Leeds
  • University of Southampton
  • University of St. Andrews
  • University of Tasmania
  • University of Washington

Fieldwork and data collection

A wide range of data parameters were collected for this programme. Physical and chemical measurements of the ocean close to and next to the ice shelf were made using instruments deployed from ship, on moorings, on autonomous platforms and seal tags. Measurements were also made of the glaciers and ice shelfs including radar and seismic surveys and ice cores. There were also meteorological and atmospheric measurements taken. For more information about the data collected on each of the four projects see the project web pages.

Data management

Data management for ocean data will be done by the British Oceanographic Data Centre whilst ice data will be managed by the Polar Data Centre.

For more information about iSTAR programme see the: iSTAR Programme Website


Ocean2ice: Processes and variability of ocean heat transport toward ice shelves in the Amundsen Sea Embayment (iSTAR A)

Background and objectives

Ocean2ice (otherwise referred to as iSTAR A) is a project that is part of NERC's Ice Sheet Stability programme. The project was designed to investigate how relatively warm water gets close to and beneath glaciers in the Antarctic and what impact this warm water has on the rate of ice melt at these sites. This research and collection of data will to feed in to climate and sea level forecasting and research. This project was funded by the Natural Environment Research Council.

Participants

The principal investigator for the Ocean2ice project is Professor Karen Heywood, University of East Anglia. Other participants in the project represent the following organisations:

  • British Antarctic Survey
  • National Oceanography Centre
  • University of East Anglia
  • University of Southampton
  • University of St. Andrews

Fieldwork and data collection

Oceanographic data were collected from a wide range of instruments from the research ship RRS James Clark Ross between 26 January and 08 March 2014 in the Amundsen Sea. Data collected include measurements of the physical conditions (including temperature and salinity), current speeds and directions, chemical measurements of the water column (including oxygen and chlorophyll-a concentrations). A fleet of Seagliders (ocean robots that measure physical parameters including temperature, salinity and current speeds and directions) were also deployed to measure conditions close to the ice shelf. Moorings were deployed by the project and have measured conditions in the area over a couple of years. In addition Seal tags (small sensors glued to the fur of seals which fall off when the seals moult their fur) were deployed and transmit data back via satellite networks to scientists. These seal tag deployments give the scientists the rare opportunity to measure water properties below the ice shelf.

Data management

All data collected by the Ocean2ice project are to be submitted to the British Oceanographic Data Centre for careful storage, quality control, archiving and distribution to scientists, education, industry and the public.

For more information about Ocean2ice see the iSTAR A project page


Data Activity or Cruise Information

Cruise

Cruise Name JR20140126 (JR294, JR295)
Departure Date 2014-01-26
Arrival Date 2014-03-08
Principal Scientist(s)Karen J Heywood (University of East Anglia School of Environmental Sciences)
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
B nominal value
Q value below limit of quantification