Metadata Report for BODC Series Reference Number 2053002
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
Data Description |
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Time Co-ordinates(UT) |
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Parameters |
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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
RD Instruments- Ocean Surveyor 75kHz Vessel mounted ADCP.
Long-Range Mode | ||
---|---|---|
Vertical Resolution Cell Size3 | Max. Range (m)1 | Precision (cm/s)2 |
8m | 520 - 650 | 30 |
16m | 560 - 700 | 17 |
High-Precision Mode | ||
Vertical Resolution Cell Size3 | Max. Range (m)1 | Precision (cm/s)2 |
8m | 310 - 430 | 12 |
16m | 350 - 450 | 9 |
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
DY113 ORCHESTRA VMADCP Data: Processing by BODC
The data arrived at BODC in two CODAS formatted NetCDF files containing data collected from the 75 kHz and a 150 kHz vessel mounted ADCPs (VMADCP) of RRS Discovery cruise DY113. The data were reformatted to BODC's internal NetCDF format.
During transfer the originator's variables were mapped to unique BODC parameter codes. The following table shows the parameter mapping.
Originator's variable | Units | BODC Code | Units | Comments |
---|---|---|---|---|
time | days | ELTMYEAR | days | - |
lat | degrees | ALATGP01 | degrees | - |
lon | degrees | ALONGP01 | degrees | - | u | m/s | LCEWAS01 | cm/s | Unit conversion applied (*100). Eastward values are positive, and values are corrected for ship's velocity. |
v | m/s | LCNSAS01 | cm/s | Unit conversion applied (*100). Northward values are positive, and values are corrected for ship's velocity. |
depth | m | DBINAA01 | m | - |
- | - | BINNUMBR | dimensionless | Neutral integer label for the ADCP sampling bins starting at 1 for the bin nearest to the instrument. |
uship | m/s | APEWGP01 | cm/s | Unit conversion applied (*100). Eastward values are positive. |
vship | m/s | APNSGP01 | cm/s | Unit conversion applied (*100). Northward values are positive. |
pg | % | PCGDAP01 | % | - |
amp | dB | ASAMAS01 | dB | - |
pflag | dimensionless | - | - | Not transferred as parameter but as u and v flags. Used by CODAS processing to flag u and v parameters. |
heading | degress | - | Not transferred. Available upon request. | |
num_pings | count | - | - | Not transferred. Available upon request. |
tr_temp | �C | - | - | Not transferred. Available upon request. |
Following transfer the data were screened using BODC in-house visualisation software. Improbable data values were assigned the appropriate BODC data quality flag. Missing data values, where present, were changed to the missing data value and assigned a BODC data quality flag.
DY113 ORCHESTRA VMADCP Data: Processing by Originator
The following were taken from the RRS Discovery Cruise DY113 in February - March 2020. Data were collected using Teledyne RDI Ocean Surveyor 75 kHz and 150 kHz vessel mounted ADCPs on board the RRS Discovery. The instruments were set to sample throughout the cruise in the Southern Ocean.
Data were acquired using the UHDAS software package.
ADCP setup
Variable | Teledyne RDI OS 75 kHz VMADCP | Teledyne RDI OS 150 kHz VMADCP |
---|---|---|
Transducer depth | 6 m | 6 m |
Number of Bins | 60 | 40 |
Bin size | 16 m | 8 m |
Blanking distance | 8 m | 4 m |
Range | 30 - 650 m | 18 - 330 m |
Throughout the cruise the instruments were set in "narrowband" mode and alternating between "bottom tracking" and "water tracking" where appropriate.
Data acquisition and processing were handled by UHDAS (University of Hawaii Data Acquisition System). This software handles both acquisition and CODAS (common ocean data access sytem) first pass processing. UHDAS automates the removal of ship velocity and heading correction with GPS derived heading. The ADCP data were processed into 5 minute averages.
Visual analysis was conducted alongside the automated CODAS process. While underway, turbulence and bubbles caused by the engines and ship movement sometimes corrupted the upper bins. Most of this was removed using the ringing and ship speed threshold. An additional error velocity threshold was applied where necessary for near bottom velocities. Some instances of scattering layer bias were observed and manually removed. Isolated points were removed if they were very few or if the velocities looked wrong. The 75 kHz was far noisier than the 150, therefore more editing was necessary.
After the visual editing, the amplitude and phase calibrations were determined from the watertrack data. Larger calibrations were needed on the 75 kHz data than on the 150 kHz, please see the cruise report (Firing et al., 2020) for more details.
The two instruments were then compared using the compare mode in the CODAS software to check if more editing was needed. Once the data were deemed good, they were output in the CODAS NetCDF format.
Results
The range of the 75 kHz instrument was reduced during processing. The data quality from both instruments is good, although there are some differences between them which were left in cases where it was not clear which reading was better. There is no data from 2nd March 2020 18:30 until the 5th of March 2020 16:00 while the ship stayed in Port Stanley, Falkland Islands.
References
Firing, Y.L. et al, 2020. RRS Discovery Cruise DY113, 3 February - 13 March 2020. Repeat hydrographic measurements on GO-SHIP lines SR1b and A23. Southampton, UK: National Oceanography Centre, Southampton, 116pp., National Oceanography Centre Cruise Report, No. 67.
Project Information
Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA)
The Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) is a £8.4 million, five year (2016-2021) research programme funded by the Natural Environment Research Council (NERC). The aim of the research is to to advance the understanding of, and capability to predict, the Southern Ocean's impact on climate change via its uptake and storage of heat and carbon. The programme will significantly reduce uncertainties concerning how this uptake and storage by the ocean influences global climate, by conducting a series of unique fieldwork campaigns and innovative model developments.
Background
ORCHESTRA represents the first fully-unified activity by NERC institutes to address these challenges, and will draw in national and international partners to provide community coherence, and to build a legacy in knowledge and capability that will transcend the timescale of the programme itself.
It brings together science teams from six UK research institutions to investigate the role that the Southern Ocean plays in our changing climate and atmospheric carbon draw-down. It is led by British Antarctic Survey, in partnership with National Oceanography Centre, British Geological Survey, Plymouth Marine Laboratory, the Centre for Polar Observation and Modelling and the Sea Mammal Research Unit.
The oceans around Antarctica play a critical a key role in drawing down and storing large amounts of carbon and vast quantities of heat from from the atmosphere. Due to its remoteness and harsh environment, the Southern Ocean is the world's biggest data desert, and one of the hardest places to get right in climate models. The ORCHESTRA programme will make unique and important new measurements in the Southern Ocean using a range of techniques, including use of the world-class UK research vessel fleet, and deployments of innovative underwater robots. The new understanding obtained will guide key improvements to the current generation of computer models, and will enhance greatly our ability to predict climate into the future.
The scope of the programme includes interaction of the Southern Ocean with the atmosphere, exchange between the upper ocean mixed layer and the interior and exchange between the Southern Ocean and the global ocean.
Further details are available on the ORCHESTRA page.
Participants
Six different organisations are directly involved in research for ORCHESTRA. These institutions are:
- British Antarctic Survey (BAS)
- National Oceanography Centre (NOC)
- Plymouth Marine Laboratory (PML)
- British Geological Survey (BGS)
- Centre for Polar Observation and Modelling (CPOM)
- Sea Mammal Research Unit (SMRU)
GO-SHIP are a third party organisation that, although not directly involved with the programme, will conduct ship based observations that will also be used by ORCHESTRA.
Research details
Three Work Packages have been funded by the ORCHESTRA programme. These are described in brief below:
-
Work Package 1: Interaction of the Southern ocean with the atmosphere
WP1 will use new observations of surface fluxes and their controlling parameters in order to better constrain the exchanges of heat and carbon loss across the surface of the Southern Ocean. -
Work Package 2: Exchange between the upper ocean mixed layer and the interior.
This work package will combine observationally-derived data and model simulations to determine and understand the exchanges between the ocean mixed layer and its interior. -
Work Package 3: Exchange between the Southern Ocean and the global ocean .
This WP will use budget analyses of the hydrographic/tracer sections to diagnose the three-dimensional velocity field of the waters entering, leaving and recirculating within the Southern Atlantic sector of the Southern ocean. -
Fieldwork and data collection
The campaign consists of 12 core cruises on board the NERC research vessels RRS James Clark Ross and RRS James Cook and will include hydrographic/tracer sections conducted across Drake Passage (SR1b), the northern Weddell Sea/Scotia Sea (A23), the northern rim of the Weddell Gyre (ANDREXII) and across the South Atlantic (24S). Section I6S will be performed by GO-SHIP Project Partners. Measurements will include temperature, salinity, dissolved oxygen, velocity, dissolved inorganic carbon, total alkalinity, inorganic nutrients, oxygen and carbon isotopes, and underway meteorological and surface ocean observations including pCO2.
Tags will be deployed on 30 Weddel seals and these will provide temperature and salinity profiles that can be used alongside the Argo data.
Autonomous underwater ocean gliders will conduct multi-month missions and will deliver data on ocean stratification, heat content, mixed layer depth and turbulent mixing over the upper 1 km, with previously-unobtainable temporal resolution. These gliders will be deployed in the Weddell Gyre and the ACC.
Field campaigns with the MASIN meteorological aircrafts will be conducted flying out of Rothera and Halley research stations and the Falkland Islands. These campaigns will deliver information on key variables relating to air-sea fluxes (surface and air temperature, wind, humidity, atmospheric CO2, radiation, turbulent fluxes of heat, momentum and CO2), in different sea ice conditions and oceanic regimes.
Eart Observation datasets will be used to inform the programme on the properties of the ocean, sea ice and atmosphere and on interactions between them.
A cluster of 6 deep ocean moorings in the Orkney Passage will collect year round series of AABW temperatre and transport. This work connects to the NERC funded project Dynamics of the Orkney Passage Outflow (DYNOPO).
The UK Earth System model (UKESM) and underlying physical model will be used to conduct analyses of heat and carbon uptake and transport by the Southern Ocean and their links to wider climate on decadal timescales.
An eddy-resolving (1/12°) sector model of the ocean south of 30°S with 75 vertical levels, will be built using the NEMO model coupled to the Los Alamos sea ice (CICE) model. The improvements on the ocean boundary layer will be based from the results from the NERC-funded OSMOSIS project and the inclusion of tides.
20-5 year runs of an adjoint model will be conducted to determine how key forcings and model states affect the uptake and subduction of heat and carbon by the ocean.
Data Activity or Cruise Information
Cruise
Cruise Name | DY113 |
Departure Date | 2020-02-04 |
Arrival Date | 2020-03-13 |
Principal Scientist(s) | Yvonne L Firing (National Oceanography Centre, Southampton) |
Ship | RRS Discovery |
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 |