Metadata Report for BODC Series Reference Number 679765
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
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 150kHz Narrow Band Acoustic Doppler Current Profiler
Specifications
| Water velocity measurements relative to the ADCP | |
|---|---|
| Accuracy (long term) | 0.5 % of measured velocity ± 0.5 cm/s |
| Statistical uncertainty for one ping (cm/s) | Depth cell length of 4, 8, 16 m = 26, 13, 6.5 respectively (for horizontal velocities using the standard transducer) |
| Ping rate (pings per second) | 2 (100 pings averaged in ADCP) |
| Maximum profiling range (meters) | 290 |
| Minimum range to start of first depth cell (meters) | 4 |
| Number of depth cells | 8 to 128 |
| Velocity range | ± 0.01 to 9.5 m/s (horizontal) |
| Velocity resolution (cm/s) | 0.25 or 0.125 |
| Velocity measurements relative to the bottom and measurement of bottom depth | |
| Accuracy | 0.5% of measured velocity ± 0.5 cm/s |
| Statistical uncertainty of one ping (percent of measured velocity) | 3.5 (for horizontal velocities using the standard transducer) |
| Ping rate (pings per second) | 0.9 (100 pings averaged in ADCP) |
| Depth range | 290 (the maximum depth range can be up to 1.5 times greater than specified) |
| Bottom depth resolution (meters) | 4 |
| Velocity range | ± 0.01 to 9.5 m/s (horizontal) |
| Velocity resolution (cm/s) | 0.25 or 0.125 |
| Measurement of echo intensity | |
| Accuracy (with temperature correction) | Before calibration : ± 8 dB, After calibration: ± 3 dB |
| Statistical uncertainty for one ping | Approximately ± 5 dB |
| Ping rate (pings per second) | 2 (100 pings averaged in ADCP) |
| Profiling range (meters less than for water velocity measurement) | 64 |
| Number of depth cells | 8 to 128 |
| Dynamic range | 80 dB |
| Resolution | 0.45 dB typical (temperature/system dependent) |
| Data communication | |
| Interface | Modified RS-232/422 serial at baud rates of 300-19,200 |
| Data format | Binary (8-bit) or ASCII (76-character) lines separated by a carriage return/line feed. |
| Data storage capacity | 2 MB (standard); expandable to 40 MB in 1 and/or 2 MB increments |
| Power requirements | |
| ADCP electronics | Voltage range (VDC) 6-12; Standby current (amps) 0.0002; Operate current (amps) 0.24; Peak current (amps) 0.5 |
| transmit and EPROM recorder | Voltage range (VDC) 20-40; Standby current (amps) 0.0001; Operate current (amps) 0.10; Peak current (amps) 2.0 |
| CTD sensors | Voltage range (VDC) 12-20; Standby current (amps) 0.0001; Operate current (amps) 0.022; Peak current (amps) 0.05 |
| Temperature sensor | |
| Accuracy | ± 0.2°C |
| Time constant | Approximately 2 minutes |
| Range | -5° to 45°C |
| Resolution | 0.012°C |
| Environmental | |
| Operating temperature | -5°C to 40°C |
| Humidity | Must be non-condensing |
| Depth capability | 35 meters (transducer only) |
| Physical characteristics | |
| Weight in air | 67.6 kg |
| Weight in water | 25.0 |
| Diameter | 45.9 cm |
| Length | 141.4 cm |
BODC processing
Data were provided to BODC in 26 PStar binary files in the form adp300##.abs. Three of these files were found to contain a combination of the other files and were basically duplicates of the data. Therefore BODC only transferred 23 files which were numbere from 30001 to 30023. BODC processing involved transferring the data from PStar format to a BODC-defined subset of NetCDF format using BODC generated Matlab code.
During transfer the orignator's variables are mapped to unique BODC parameter codes. The following table shows the parameter mapping.
| Originator's variable | Units | Description | BODC Code | Units |
|---|---|---|---|---|
| lat | degrees | Latitude | ALATZZ01 | degrees |
| lon | degrees | Longitude | ALONZZ01 | degrees |
| ve | cm-1 | Eastward platform velocity | APEWGP01 | cm-1 |
| vn | cm-1 | Northward platform velocity | APNSGP01 | cm-1 |
| bindepth | metres | Bin depth | DBINAA01 | metres |
| Distance Run | km | distrun | DSRNGR01 | km |
| ampl | decibels | Signal return amplitude | ASAMAS01 | decibels |
| absve | cm-1 | Eastward current velocity (Eulerian) | LCEWAS01 | cm-1 |
| absvn | cm-1 | Northward current velocity (Eulerian) | LCNSAS01 | cm-1 |
| velerr | cm-1 | Current velocity error | LERRAS01 | cm-1 |
| evelcal | cm-1 | Relative eastward current velocity | LREWAS01 | cm-1 |
| nvelcal | cm-1 | Relative northward current velocity | LRNSAS01 | cm-1 |
| velvert | cm-1 | Upward current velocity | LRZAAS01 | cm-1 |
| good | % | Percentage good return signal | PCGDAP01 | % |
Following transfer the data were screened using BODC in-house visualisation software. Suspect data values were assigned the appropriate BODC data quality flag. Missing data values were changed to the missing data value and assigned a BODC data quality flag
Originator's processing
An RDI 150kHz Vessel-Mounted Acoustic Doppler Current Profiler (VM-ADCPs) was operated on Discovery 300. The 150 kHz ADCP is mounted in the hull 1.75 m to port of the keel, 33 m aft of the bow at the waterline and at an approximate depth of 5 m. The following table describes the setup of the 150kHz ADCP.
| Frequency dependent constant | 4.17e5 |
| Power into water (W) | 183.15 |
| Dimensionless noise factor | 8.95 |
| Bin length (m) | 8 |
| Blanking distance (m) | 8 |
The ADCP was logged using RDI Data Acquisition Software (DAS) version 2.48 with profiler firmware 17.20. The instrument was configured to sample over 120 second intervals with 64 bins of 8 m thickness, pulse length 4 m and a blank beyond transmit of 4 m. It was planned to calibrate the ADCP early in the cruise but problems with ashtech and PStar mean that it is unlikely a sensible calibration can be determined. The heading offset is approximately 45 degrees and this is accounted for in the DAS software.
The ADCP data were continually logged by the level C computer and transferred every other day to the PStar data structure. They were then processed using standard PStar processing scripts so that the final version of the data were in files named adp300##.abs. More information on the data processing steps can be found on page 132 of the cruise report which is accessible through themetadata summary report.
Project Information
CROZET (Benthic CROZEX)
The CROZET project was a multidisciplinary Benthic study that compliments the CROZet natural iron bloom EXport experiment (CROZEX). It was a Natural Environment Research Council (NERC) funded project (grant number NER/A/S/2003/00573).
The principle objective of CROZET was "To assess how biogeochemical composition and flux of Organic Matter (OM) to the deep-sea floor drive benthic community structure, dynamics and diversity at two sites with contrasting primary production regimes".
Specific hypotheses tested were:
- That the variability in biogeochemical composition as well as the total flux of OM reaching the abyssal seafloor is dependent on the productivity of the overlying surface waters.
- That the biogeochemical composition of incoming OM is imprinted on the biochemistry of key detritovores.
- That key nano-nutrients are critical for the reproduction of some deep-sea species and thus variations in OM flux affect sediment community structure and diversity.
- That variations in total OM flux also influence benthic rate processes (e.g. faunal activity).
The University of Liverpool Department of Earth Science hosted the project with particiption from another seven research centres/universities.
The project ran from December 2005 to September 2008 with the primary marine data collection during RRS Discovery cruise D300 between 1st December 2005 and 14th January 2006. The sediment trap moorings for this project were deployed during the RRS Discovery CROZEX cruises D285 and D286 one year previously.
The cruise primarily sampled stations M5 (an eutrophic region subject to photoplankton blooms) and M6 (to the south of the Crozet Islands and an oligotrophic High Nutrient Low Chlorophyll (HNLC) area) previously occupied during the CROZEX cruises and described in Pollard et al. (2007). The two contrast regions allowed a comparison of the benthic communities that were:
- At the same depth.
- In the same physical setting (topographic and hydrographic).
- Interconnected (with no physical barrier between them).
Where possible the following observations were conducted at each major station:
- Underway navigation, surface, meteorology and bathymetry throughout the cruise
- Underway sampling of:
- Salinity
- Nutrients (Nitrogen and Phosphorus)
- Chlorophyll-a
- Dissolved Iron
- 150kHz Vessel-Mounted Acoustic Doppler Current Profiller (VMADCP) data throughout the cruise
- Full water column CTD stations for salinity, temperature, chlorophyll and dissolved oxygen. CTD rig included a Lowered Acoustic Doppler Current Profiller (LADCP). CTD water bottles were sampled for:
- Salinity
- Particulate Organic Carbon (POC)
- Particulate Organic Nitrogen (PON)
- Bacterial biomass and community structure using DNA analyses
- MPN enumeration and isolation of marine bacteria
- Particulate iron
- Chloropyhll-a
- Stand Alone Pumps with analyses of:
- Organic biogeochemistry
- Bacterial biomass and community structure using DNA analyses
- MPN enumeration and isolation of marine bacteria
- Archael bacteria
- Particulate Organic Carbon (POC)
- Particulate Organic Nitrogen (PON)
- Particulate iron
- Megacoring with analyses of:
- Total Organic Carbon (TOC)
- Total Nitrogen (TN)
- Hydrolysable amino acids
- Bacterial biomass and community structure using DNA analyses
- MPN enumeration and isolation of marine bacteria
- Nematodes
- Polychaetes
- Pigments
- Pigment degradation
- Meiofauna
- Foraminifera
- Macrofauna
- Pore fluid geochemistry
- Biomarkers
- Lipids
- Solid phase geochemistry
- Bacteria
- Holothurian sample photography
- WASP sea floor photography and video for study of benthic megafaunal populations
- Fish RESPirometry Lander (FRESP) deployments
- RObust BIOdiversity Lander (ROBIO) deployments (included a current meter)
- Demersal ichthyofauna sampling with analyses of:
- Species
- Wet weight
- Length (total, standard, head and pre-anal)
- Demersal ichthyofauna macrouridae (Rattail) sex, stomach weight, liver (weight, fullness) and sexual maturity
- Bacterial long-term enrichment incubations
- SPRATS Sampling pressure retaining system deployments
- Holothurian pigment analysis (gut and gonad)
- Holothurian - molecular (DNA) analysis
- Holothurian Bacterial samples (gut and cloaca)
- Holothurian lipid analysis
The project has produced significant findings including the discovery of six new species of fish. Further information on the project can be found in the D300 cruise report and the CROZET project web pages.
References
Pollard R., Sanders R., Lucas M. and Statham P., 2007. The Crozet natural iron bloom and export experiment (CROZEX). Deep-Sea Research II, 54, 1905-1914.
Data Activity or Cruise Information
Cruise
| Cruise Name | D300 |
| Departure Date | 2005-12-01 |
| Arrival Date | 2006-01-14 |
| Principal Scientist(s) | George Wolff (University of Liverpool Department of Earth and Ocean Sciences) |
| 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 |
