Metadata Report for BODC Series Reference Number 1902131
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
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Problem Reports
No Problem Report Found in the Database
JR20120120 (JR255A) Underway: Surface Hydrography Data Quality Document
Flow RateWhen the flow rate is less than 0.55 L mn-1 any corresponding data have been flagged (chlorophyll, conductivity, salinity, tempeature, sound velocity). This is due to suspected blocking of the non-toxic supply by ice.
All ChannelsCycle 18323 of the data series was deleted due to a duplicate time. All corresponding data for this cycle was also deleted as the values were consistent with the previous instance of this time stamp.
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
Turner Designs 10AU Field Fluorometer
The Turner Designs 10AU is designed for continuous-flow monitoring or discrete sample analyses of fluorescent species. A variety of optical kits with appropriate filters and lamps are available for a wide range of applications. Individual filters and lamps are also available for customised applications.
Standard optical kits include those for chlorophyll-a (extracted and/or in vivo), phycocyanin, phycoerythrin, CDOM, ammonium, rhodamine and fluorescein dye tracing, crude oil, refined oil, histamine and optical brighteners.
The instrument's light source is a 4 watt lamp and the detector is a photomultiplier tube with a standard detection range of 300-650 nm. A red-sensitive version with a detetion range of 185-970 nm is also available.
Specifications
| Operating temperature | 0 to 55°C |
| Detector | PhotoMultiplier Tube 300 to 650 nm (standard) 185 to 870 nm (Red) |
| Detection Limits: Extracted Chlorophyll-a Rhodamine WT Dye Fluorescein Dye | 0.025 µg L-1 0.01 ppb (in potable water) 0.01 ppb (in potable water) |
| Linear range: Extracted Chlorophyll-a Rhodamine WT Dye Fluorescein Dye | 0 to 250µg L-1 0 to 250 ppb 0 to 250 ppb |
Further details can be found in the manufacturer's specification sheet.
WETLabs C-Star transmissometer
This instrument is designed to measure beam transmittance by submersion or with an optional flow tube for pumped applications. It can be used in profiles, moorings or as part of an underway system.
Two models are available, a 25 cm pathlength, which can be built in aluminum or co-polymer, and a 10 cm pathlength with a plastic housing. Both have an analog output, but a digital model is also available.
This instrument has been updated to provide a high resolution RS232 data output, while maintaining the same design and characteristics.
Specifications
| Pathlength | 10 or 25 cm |
| Wavelength | 370, 470, 530 or 660 nm |
| Bandwidth | ~ 20 nm for wavelengths of 470, 530 and 660 nm ~ 10 to 12 nm for a wavelength of 370 nm |
| Temperature error | 0.02 % full scale °C-1 |
| Temperature range | 0 to 30°C |
| Rated depth | 600 m (plastic housing) 6000 m (aluminum housing) |
Further details are available in the manufacturer's specification sheet or user guide.
JR20120120 (JR255A) Underway: Surface Hydrography Instrument Description
The surface hydrography instruments used to collect this data set are presented in the table below.
| Manufacturer | Model | Sensor | Serial number | Last calibration date |
| Sea Bird Electronics | SBE45 | Thermosalinograph | 4538936-0130 | 23/07/2010 |
| WetLabs | C-Star | Transmissometer | CST-1279DR | 25/03/2012 |
| Chelsea Technologies | 10 AU-005 | Fluorometer | 6456 RTX | - |
| Litre Meter | LMSPFA | Flow meter | 05/811950 | 09/06/2011 |
| Sea Bird Electronics | SBE48 | Hull temperature | - | - |
Litre Meter LMSPFA.05 flowmeter
The LMSPFA.05 is a Pelton Wheel flowmeter designed to monitor water flow rates for pumped systems such as ships' continuous seawater supplies. The instrument can measure low flow rates in the range 0.006 to 0.1 l min-1. The flow through the inlet of the meter is directed onto a rotor, whose rotation rate is directly proportional to the flow rate. A small sensing coil detects ferrites mounted in the flow meter rotor blade tips as they pass. Sapphire bearings are used to reduce friction, while maintaining mechanical robustness.
The LMSPFA series comprises several models that operate in the same manner but have different flow rate ranges and pressure drops.
The specification sheet can be accessed here Litre Meter LMSPFA.
Specifications
| Pressure rating | 40 bar (120 bar optional) |
| Flow range | from 0.004 to 0.06 up to 0.1 to 28 l min-1 |
| Temperature rating | -20 to 70°C |
| Viscosity range | up to 10 cPs |
| Accuracy | ± 2% of actual reading for the top 90% of range ± 0.5% FSD for the bottom 10% of range |
| Repeatibility | ± 0.2% reading over top 90% of range |
LMSPFA model specifications
| Model type | Flow rate range (l min-1) | Pressure drop |
| 003 | 0.004 to 0.06 | 0.18 bar @ 0.03 l min-1 0.7 bar @ 0.06 l min-1 |
| 005 | 0.006 to 0.1 | 0.18 bar @ 0.05 l min-1 0.7 bar @ 0.1 l min-1 |
| 01 | 0.01 to 0.25 | 0.33 bar @ 0.125 l min-1 1.3 bar @ 0.25 l min-1 |
| 05 | 0.02 to 1.3 | 0.18 bar @ 0.65 l min-1 0.74 bar @ 1.3 l min-1 |
| 24 | 0.03 to 4.3 | 0.3 bar @ 2 l min-1 1.2 bar @ 4.3 l min-1 |
| 45 | 0.04 to 6.3 | 0.23 bar @ 3 l min-1 1.3 bar @ 6.3 l min-1 |
| 48 | 0.06 to 8 | 0.3 bar @ 4 l min-1 1.2 bar @ 8 l min-1 |
| 90 | 0.08 to 15 | 0.25 bar @ 9 l min-1 0.7 bar @ 15 l min-1 |
| 220 | 0.1 to 28 | 0.24 bar @ 10 l min-1 1.8 bar @ 28 l min-1 |
Sea-Bird SBE 48 Hull Temperature Sensor
The SBE 48 is a high-accuracy temperature recorder with non-volatile memory, designed for shipboard determination of sea surface temperature. Mounted with magnets just below the water line, the SBE 48's temperature sensor is in contact with the inside of the ship's hull. The SBE 48's internal battery runs the real-time clock and can be used to power the instrument for very short deployments; external power is recommended for typical deployments.
Data are recorded in memory and can also be output in real-time in engineering units. Memory capacity exceeds 4.7 million samples of temperature and time; this yields approximately 54 days of data when sampling every 1 sec.
Specifications
| Range | -5 to +35 °C |
|---|---|
| Initial accuracy | ± 0.002°C |
| Resolution | 0.0001 °C |
| Typical stability (per month) | 0.0002 °C |
| Sampling Speed | Approximately 1 Hz (1 sample/sec), or user-programmable 3-sec to 9-hour intervals |
| Memory | 4.7 million samples (temperature and time) |
Further details can be found in the manufacturer's specification sheet.
SeaBird MicroTSG Thermosalinograph SBE 45
The SBE45 MicroTSG is an externally powered instrument designed for shipboard measurement of temperature and conductivity of pumped near-surface water samples. The instrument can also compute salinity and sound velocity internally.
The MicroTSG comprises a platinum-electrode glass conductivity cell and a stable, pressure-protected thermistor temperature sensor. It also contains an RS-232 port for appending the output of a remote temperature sensor, allowing for direct measurement of sea surface temperature.
The instrument can operate in Polled, Autonomous and Serial Line Sync sampling modes:
- Polled sampling: the instrument takes one sample on command
- Autonomous sampling: the instrument samples at preprogrammed intervals and does not enter quiescence (sleep) state between samples
- Serial Line Sync: a pulse on the serial line causes the instrument to wake up, sample and re-enter quiescent state automatically
Specifications
| Conductivity | Temperature | Salinity | |
|---|---|---|---|
| Range | 0 to 7 Sm-1 | -5 to 35°C | |
| Initial accuracy | 0.0003 Sm-1 | 0.002°C | 0.005 (typical) |
| Resolution | 0.00001 Sm-1 | 0.0001°C | 0.0002 (typical) |
| Typical stability (per month) | 0.0003 Sm-1 | 0.0002°C | 0.003 (typical) |
Further details can be found in the manufacturer's specification sheet.
JR20120120 (JR255A) Underway: Surface Hydrography Processing Procedures Document
Originator's Data Processing
Sampling Strategy
RRS James Clark Ross cruise JR255A was deployed as part of the Gliders: Excellent New Tools for Observing the Ocean (GENTOO) project. JR255A was a 2 week cruise departing from port Stanley in the Falkland Islands. The GENTOO fieldwork took place in the Weddell Sea where gliders were used primarily for data gathering.
Data Processing
A script on the JRLC server (written by Bastien Queste) was run automatically every hour at quarter past to update the file the oceanlogger matlab file.
The routine first creates a query file which contains a GMT start and end time. The start time is either the first date recorded by the oceanlogger (18:36 17/01/2012) or the last date stored in the oceanlogger matlab file (if present) and the current time as an end time.
The sea surface hydrography measurements were performed by a number of instruments in the ship's flow through system and a temperature sensor located near the flow through intake, at the hull. The depth of the flow through intake was 7 m.
The data streams were logged every second to the SCS system and merged into a comma separated file format, whereas the header information was stored in .TPL files. This file also contained data from the meteorological sensors.
Before the results were mapped, the outliers are removed from the data. The Originator chooses a threshold T (e.g. 20), for each parameter and then calculates x1 —value of the parameter corresponding to the Tth percentile- and x2 —for the 100-T th percentile.
After testing the scaling factor (SF) is set to 7, then the Originator sets to NaN any outliers with the following equations:
x < x1 — SF*(x2 — x1)
x > x2 + SF*(x2 — x1)
Data points where the flow rate was inferior to 0.55 L/mn were discarded.
Files delivered to BODC
| Filename | Content description | Format | Interval | Start date/time (UTC) | End date/time (UTC) | Comments |
| JR255_oceanlogger.mat | Surface hydrography | .mat | 60s | 17-Jan-2012 18:37:00 | 03-Feb-2012 13:14:00 | - |
BODC Processing
All sea surface hydrography parameters, were transferred to internal QXF format and matched against BODC codes, as presented in the table below. There was no need to apply unit conversions as the originator's units were similar to the units described on the BODC parameter dictionary.
BODC processing procedures included loading of data and reduction through averaging, visual screening and flagging of anomalous values.
The originator's variables were mapped to appropriate BODC parameter codes as follows:
JR255_oceanlogger.mat
| Originator's variable | Originator's units | BODC Code | BODC Units | Comments |
| tstemp | degrees C | TMESSG01 | degrees C | hull sensor |
| sstemp | degrees C | TEMPHU01 | degrees C | Remote sensor |
| sampletemp | degrees C | TMESFL01 | degrees C | |
| chlorophyll | µg l-1 | CHLTVOLU | mg m-3 | Equivalent units |
| salinity | - | PSALSU01 | dimensionless | |
| conductivity | s m-1 | CNDCSG01 | s m-1 | |
| sound_velocity | m s-1 | SVELSG01 | m s-1 | |
| flowrate | l min-1 | INFLTF01 | l min-1 |
BODC's procedures included the transfer of originator's parameters into BODC codes and visual screening in Edserplo. N flags were applied during the transfer to absent values.
Project Information
Gliders: Excellent New Tools for Observing the Ocean (GENTOO)
Funding
Funding was provided by NERC through the 11th round of the Antarctic Funding Initiative (AFI), an annual competition-based award which is supported logistically by the British Antarctic Survey (BAS). The award had a total value of £1,070,531 which was split between different researchers at various international institutions in the form of grants, fellowships and training grant records.
Project dates - 06 September 2010 to 31 March 2015
Background
Research has shown that surface waters surrounding Antarctica play an important role in driving the global oceanic circulation as they are subjected to ideal physical conditions to become denser and sink at specific locations. The mapping of these locations and the identification of the properties of these water cells have been relying on expensive and season-dependent shipborne observations in impractical polar seas. This study aims at revealing the potential of Seagliders, which are autonomous, inexpensive and sustainable underwater vehicles able to carry out certain physical, biological and chemical measurements of the water column all year round. Seagliders were deployed in the Weddell Sea, as the recent collapse of the Larsen Ice Shelf has raised questions on whether dense water may now be spilling off the continental shelf on the eastern side of the Antarctic Peninsula. Changes in location of deep water formation may affect local oceanic currents and consequently the global circulation and the Earth's climate; reliable mapping and description of the Antarctic waters are therefore key to generate accurate climate and circulation models and predictions. Possible changes in the ocean currents also affect the organisms living in the waters near Antarctica. In particular, krill lay eggs around the Antarctic Peninsula and rely on ocean currents to transport them to South Georgia. It is important to determine whether changes in the local circulation may impact krill's ecosystem, as animals such as whales, seals and penguins feed on them and they support a multi-million pound krill fishing industry. In light of the decreasing availability of resources for an increasing human population, the possibility of krill's immunity to temperature and circulation changes may result in a popular food resource for people in the future.
Objectives
The main objectives of the GENTOO project depend on a critical evaluation of the ability to measure current velocity and krill biomass from a glider.
1) To quantify and understand the possible new source of dense water overflow and its variability; to determine the outflow's potential as an early indicator of Antarctic climate change; to assess the impact of changing dense overflows on the locations and strengths of the surface currents and frontal jets; to provide valuable constraints for climate models that describe how changes in ocean circulation feedback on and regulate climate change in polar latitudes.
2) To determine the krill biomass distribution and (temporal and spatial) variability to the east of the Antarctic Peninsula and its likely impact on the circumpolar krill ecosystem; to assess the impact of any variations in the location of the frontal jets (from objective 1) on the krill biomass distribution; to alleviate a severe regional lack of field data on krill, a key species in the Antarctic food web.
Participants
Organisations directly involved- University of East Anglia, United Kingdom (Lead Research Organisation)
- NOAA - National Oceanic and Atmospheric Administration, United States
- Bjerknes Centre for Climate Research, Norway
- AWI - Alfred Wegener Institute for Polar and Marine Research, Germany
- VIMS - Virginia Institute of Marine Science, United States
- Prof. Karen Heywood, University of East Anglia, Environmental Science (Principal Investigator)
- Dr. Sophie Fielding, NERC British Antarctic Survey, Science Programmes
- Prof. Gwyn Griffiths, National Oceanography Centre, Science and Technology
- Dr. Stuart Dalziel, University of Cambridge, Applied Mathematics and Theoretical Physics
- Dr. Eugene Murphy, NERC British Antarctic Survey, Science Programmes
- Dr. Andrew Thompson, California Institute of Technology, Environmental Science and Engineering.
Methodology
During cruise RRS James Clark Ross 255A three Seagliders were deployed, and a hydrographic survey was undertaken together with nets and underway biological, chemical and physical measurements. The data gathered was analysed to meet the objectives listed above. Please read the 'Instrumentation' section below, and visit the GENTOO website for more information on the methodology and outcomes of the various research studies.
Fieldwork
- RRS James Clark Ross 255A - 20 January 2012 to 03 February 2012. Port of arrival and departure is Stanley, Falkland Islands (Malvinas). Study area - Drake Passage, Weddell Sea, Powell Basin. Principal Scientist - Dr. Karen Heywood, University of East Anglia. This was the glider deployment cruise and the primary data gathering exercise.
- RRS James Clark Ross 255B - 07 February 2012 to 22 March 2012. Port of arrival and departure is Stanley, Falkland Islands (Malvinas). This was the glider recovery cruise; other projects not linked to GENTOO shared the voyage.
Instrumentation
- Seagliders - three in total, each equipped with a Seabird CT sail (i.e. free-flushed temperature and conductivity sensors), Aandera oxygen optode and a WETLabs ECO Triplet. (Biddle et al. 2015)
- SeaBird (SBE) CTD-11plus rosette equipped with 24 12-litre Niskin bottles. Sensors installed are SBE 43 Oxygen sensor, LI-COR Biospherical PAR Sensor, Chelsea Aqua 3 Fluorometer, WET Labs C-Star Transmissometer, and Altimeter sensor.
- 300 kHz WorkHorse (WH) Lowered Acoustic Doppler Current Profiler (LADCP)
- 75 kHz RD Instruments Ocean SUrveyor (OS75) Vessel-Mounted Acoustic Doppler Current Profiler (ADCP)
- Surface drifters: 20 Clearsat-15 Minidrogue drifters with a GPS navigation option and 20 Clearsat-15 SVP Minidrigue drifters with Argos data telemetry, both purchased from Clearwater Instrumentation, Inc.
- Three AOEX-SBE Argo floats profilers produced by Webb Research Corporation USA.
- RMT8 Nets Macrozooplankton
- Guildline Autosal salinometer
- Winkler O2 titrator
- Simrad EK60 Echo Sounder
- Underway - navigation, surface and meteorology.
Contacts
| Collaborator | Organisation |
|---|---|
| Prof. Karen Heywood | University of East Anglia |
| Dr. Bastien Queste | University of East Anglia |
| Prof. Walker Smith | Virginia Institute of Marine Science |
References
Biddle, L.C., Kaiser J., Heywood K.J., Thompson A.F., and Jenkins A., 2015. Ocean glider observations of iceberg-enhanced biological production in the northwestern Weddell Sea, Geophys. Res. Lett. (42), 459-465.
Data Activity or Cruise Information
Cruise
| Cruise Name | JR20120120 (JR255A) |
| Departure Date | 2012-01-20 |
| Arrival Date | 2012-02-03 |
| 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 |
