Metadata Report for BODC Series Reference Number 648557
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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Data Identifiers |
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Time Co-ordinates(UT) |
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Spatial Co-ordinates | |||||||||||||||||||||||||||||
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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
RRS Discovery 258 600khz Lowered ADCP (LADCP)- Absolute backscatter
Deployment and originators processing
The 600 kHz Workhorse LADCP was new to SOC on this cruise. The instrument proved accessible only via the RDI Workhorse application. The main interest in the 600 kHz ADCP for the cruise was the backscatter calculation. Velocity calculations produced no sensible on-board results for the configuration selected and required further investigation. However, after a range correction (see cruise report for details), the calibrated backscatter data seem to correlate with biology in the water column. The instrument setup for the majority of casts is listed in the following table. Deviations are stations 14213, 14214, 14223, 14231 and 14244 where the bin length was 800cm and 14239 where the bin length was 400cm.
| Frequency of instrument (kHz) | 600 |
| Number of bins: | 30 |
| Beam angle | 20.0 |
| Number of pings per ensemble | 1 |
| Bin length (cm) | 200 |
| Blank before transmit (cm) | 88 |
Absolute backscatter coefficient was calculated by the method of Deines (1990). The coefficients used are listed in the table below.
| Coefficient | |
|---|---|
| Alpha | 0.153 |
| C | -141.4 |
| PdbW | 15.4 |
| Rayliegh distance | 2.9 |
Occasionally there were problems with time stamps. The profiles marked suspect in the table below are where there was disagreement between the ADCP depth and CTD depth.
| Station No. | Status | Comments |
|---|---|---|
| 14191 | Processed | |
| 14199 | Processed | |
| 14200 | Processed | |
| 14205 | Processed | |
| 14206 | Processed | |
| 14211 | Processed | |
| 14212 | Processed | |
| 14213 | Processed | |
| 14214 | Processed | |
| 14215 | Processed | |
| 14223 | Processed | |
| 14231 | Processed | |
| 14239 | Processed | |
| 14244 | Processed | |
| 14245 | Processed | |
| 14249 | Failed | |
| 14254 | Time problem | |
| 14259 | Processed | Suspect profile |
| 14263 | Processed | |
| 14267 | Processed | |
| 14275 | Failed | |
| 14283 | Processed | |
| 14287 | Processed | Suspect profile |
| 14288 | Processed | |
| 14289 | Processed | |
| 14294 | Processed | |
| 14295 | Processed |
BODC processing
A total of 24 station files where submitted to BODC. The Data were supplied in Matlab binary format. The following variables were transferred to BODC QXF format. A large number of additional variables, including CTD and navigation data, were also present in the files. These were not transferred.
| Description | Units | Originators variable |
|---|---|---|
| Pressure | Decibars | d.z |
| Absolute backscatter (MVBS) | Decibels | d.mvbs |
| Distance from transducer | Metres | d.zd |
Screening and Data quality
The data have been visually screened for obvious problems using the BODC XERPLO software. No significant problems were detected.
References
RDI, (1990). Calculating Absolute Backscatter. Technical bulletin ADCP-90-04, R D Instruments, San Diego, CA, USA.
Project Information
Marine Productivity programme (MarProd)
The Marine Productivity programme (MarProd) was a Thematic Programme of the Natural Environment Research Council. It was funded for a period of five years starting in 2000. Its main goal was "to develop coupled modelling and observation systems for the pelagic ecosystem, with emphasis on physical factors affecting zooplankton dynamics" with the following specific objectives:
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To identify the dominant spatial and temporal scales of physical parameters and zooplankton population dynamics, by observation, modelling and retrospective analysis
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To parameterise the critical processes governing zooplankton dynamics by observations and experiments
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To construct and validate spatially explicit models of zooplankton and their food and predators, capable of resolving short term changes in population structure
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To provide data for model validation by developing and applying new interdisciplinary techniques to a wide spectrum of biological and physical parameters
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To develop a database and information system for historic and new data and models.
The programme was composed of two phases: Phase 1 projects (2000-2002) focused on the use of historical datasets and existing biological models, complemented by laboratory experiments and remote-sensing analyses to gain a better understanding of the dynamics of zooplankton populations in shelf seas. The main, field-based Phase 2 of the programme (2001-2005) focused on the open ocean. The fieldwork phase took place between November 2001 and December 2002 and consisted of four surveys in the northern North Atlantic in early winter 2001 and 2002, and in spring and summer 2002.
MarProd was a major UK contribution to the international Global Ocean Ecosystem Dynamics project (GLOBEC).
Data Activity or Cruise Information
Cruise
| Cruise Name | D258 |
| Departure Date | 2001-11-01 |
| Arrival Date | 2001-12-18 |
| Principal Scientist(s) | Raymond T Pollard (Southampton Oceanography Centre), Steven J Hay (Fisheries Research Services Aberdeen Marine Laboratory) |
| 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 |
