Metadata Report for BODC Series Reference Number 444394
Scatter plots revealed data to be of suspicious quality and should therefore be used with caution.
Public domain 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.
The recommended acknowledgment is
"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."
BODC Current Meter Screening
BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.
Header information is inspected for:
- Irregularities such as unfeasible values
- Inconsistencies between related information. For example:
- Depths of meter and sea bed.
- Times for mooring deployment and for start/end of data series.
- Length of record or number of data cycles, the cycle interval, the clock error and the period over which accrued.
- Parameters stated as measured and the parameters actually present in the data cycles.
- Originator's comments on meter/mooring performance and data quality.
Documents are written by BODC highlighting irregularities which cannot be resolved.
Data cycles are inspected using time series plots of all parameters. Currents are additionally inspected using vector scatter plots and time series plots of North and East velocity components. These presentations undergo intrinsic and extrinsic screening to detect infeasible values within the data cycles themselves and inconsistencies as seen when comparing characteristics of adjacent data sets displaced with respect to depth, position or time. Values suspected of being of non- oceanographic origin may be tagged with the BODC flag denoting suspect value.
The following types of irregularity, each relying on visual detection in the time series plot, are amongst those which may be flagged as suspect:
- Spurious data at the start or end of the record.
- Obvious spikes occurring in periods free from meteorological disturbance.
- A sequence of constant values in consecutive data cycles.
If a large percentage of the data is affected by irregularities, deemed abnormal, then instead of flagging the individual suspect values, a caution may be documented. Likewise documents will highlight irregularities seen in the current vector scatter plots such as incongruous centre holes, evidence of mooring 'knock-down', abnormal asymmetry in tidally dominated records or gaps as when a range of speeds or directions go unregistered due to meter malfunction.
The term 'knock-down' refers to the situation when the 'drag' exerted on a mooring at high current speeds may cause instruments to tilt beyond the angle at which they are intended to operate. At this point the efficiency of the current sensors to accurately record the flow is reduced.
Inconsistencies between the characteristics of the data set and those of its neighbours are sought, and where necessary, documented. This covers inconsistencies in the following:
- Maximum and minimum values of parameters (spikes excluded).
- The orientation and symmetry of the current vector scatter plot.
- The direction of rotation of the current vectors.
- The approximate amplitude and periodicity of the tidal currents.
- The occurrence of meteorological events and, finally, for series for which no time check was possible, the phase.
This intrinsic and extrinsic screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC making are not introduced.
The sensor heights above sea bed and corresponding data channels:
|Parameter||Height Above Sea Bed||Serial Number|
Ocean Margin EXchange (OMEX) I
OMEX was a European multidisciplinary oceanographic research project that studied and quantified the exchange processes of carbon and associated elements between the continental shelf of western Europe and the open Atlantic Ocean. The project ran in two phases known as OMEX I (1993-1996) and OMEX II - II (1997-2000), with a bridging phase OMEX II - I (1996-1997). The project was supported by the European Union under the second and third phases of its MArine Science and Technology Programme (MAST) through contracts MAS2-CT93-0069 and MAS3-CT97-0076. It was led by Professor Roland Wollast from Université Libre de Bruxelles, Belgium and involved more than 100 scientists from 10 European countries.
The aim of the Ocean Margin EXchange (OMEX) project was to gain a better understanding of the physical, chemical and biological processes occurring at the ocean margins in order to quantify fluxes of energy and matter (carbon, nutrients and other trace elements) across this boundary. The research culminated in the development of quantitative budgets for the areas studied using an approach based on both field measurements and modeling.
OMEX I (1993-1996)
The first phase of OMEX was divided into sub-projects by discipline:
- Biogeochemical Cycles
- Biological Processes
- Benthic Processes
- Carbon Cycling and Biogases
This emphasises the multidisciplinary nature of the research.
The project fieldwork focussed on the region of the European Margin adjacent to the Goban Spur (off the coast of Brittany) and the shelf break off Tromsø, Norway. However, there was also data collected off the Iberian Margin and to the west of Ireland. In all a total of 57 research cruises (excluding 295 Continuous Plankton Recorder tows) were involved in the collection of OMEX I data.
Field data collected during OMEX I have been published by BODC as a CD-ROM product, entitled:
- OMEX I Project Data Set (two discs)
Further descriptions of this product and order forms may be found on the BODC web site.
The data are also held in BODC's databases and subsets may be obtained by request from BODC.
|Start Date (yyyy-mm-dd)||1994-06-30|
|End Date (yyyy-mm-dd)||1994-11-12|
|Organization Undertaking Activity||Royal Netherlands Institute for Sea Research|
|Country of Organization||Netherlands|
|Originator's Data Activity Identifier||10_BOBO|
|Platform Category||fixed benthic node|
OMEX BOBO Lander Deployment 10_BOBO
Site: near OMEX2
|Position||49.1873° N, 12.8218° W|
|Water depth||1453 m|
|Deployed||08 Jun 1994 |
from RRS Charles Darwin (CD86)
|Recovered||19 Sep 1995 |
from Pelagia (PLG95B)
Lander BOBO (BOttom BOundary Layer Research) consists of 4 acoustic current meters, a central data storage and command logger, two 25 cm beam SeaTech transmissometers, a conductivity/ temperature logger (SeaCat CT probe) and two underwater cameras with flashing unit.
Instruments positions on the rig
|Height above |
|2.00 m||Transmissometer SN178-D|
|1.00 m||Transmissometer SN118-D|
|1.00 m||CT probe|
|1.00 m||Current meter|
|0.75 m||Current meter|
|0.50 m||Current meter|
|0.25 m||Current meter|
|Principal Scientist(s)||Tjeerd van Weering (Royal Netherlands Institute for Sea Research)|
|Ship||RRS Charles Darwin|
Complete Cruise Metadata Report is available here
Fixed Station Information
|Station Name||OMEX I site OMEX2|
|Latitude||49° 11.46' N|
|Longitude||12° 48.00' W|
|Water depth below MSL||1418.0 m|
OMEX I Moored Instrument and CTD site OMEX2
OMEX2 was one of four fixed stations for the OMEX I project. It was visited by twelve cruises and collected a variety of data during the period June 1993 to October 1995. These include:
- Mooring deployments - Aandeera current meters with transmissometers
- CTD casts
- Net trawls
- Plankton recorders
- Water samples
The data collected a site OMEX2 lay within a box bounded by co-ordinates 49° 6.72'N, 013° 16.03'W at the southwest corner and 49° 17.2'N, 012° 44.4'W at the northeast corner, with an approximate depth of 1500 metres.
Related Fixed Station activities are detailed in Appendix 1
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
|<||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.)|
|E||End of CTD Down/Up Cast|
|G||Non-taxonomic biological characteristic uncertainty|
|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|
|O||Improbable value - user quality control|
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
|0||no quality control|
|2||probably good value|
|3||probably bad value|
|6||value below detection|
|7||value in excess|
|A||value phenomenon uncertain|
|Q||value below limit of quantification|
Appendix 1: OMEX I site OMEX2
Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.
If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.
|Series Identifier||Data Category||Start date/time||Start position||Cruise|
|444382||Multiple data types -fixed platform||1993-06-24 20:29:00||49.1885 N, 12.7333 W||FS Poseidon PO200_7|
|319390||Currents -subsurface Eulerian||1993-06-27 11:49:00||49.2872 N, 12.8193 W||FS Poseidon PO200_7|
|319389||Currents -subsurface Eulerian||1993-06-27 12:27:00||49.2872 N, 12.8193 W||FS Poseidon PO200_7|
|920244||CTD or STD cast||1993-06-29 14:29:00||49.193 N, 12.944 W||Valdivia VLD137|
|920256||CTD or STD cast||1993-06-29 15:13:00||49.179 N, 12.957 W||Valdivia VLD137|
|883705||CTD or STD cast||1993-09-25 07:41:00||49.22783 N, 12.80017 W||RV Belgica BG9322A|
|883717||CTD or STD cast||1993-09-25 12:36:00||49.25967 N, 12.80733 W||RV Belgica BG9322A|
|1271492||Water sample data||1993-09-25 12:53:00||49.25973 N, 12.80741 W||RV Belgica BG9322A|
|883729||CTD or STD cast||1993-09-25 15:46:00||49.26067 N, 12.81033 W||RV Belgica BG9322A|
|883730||CTD or STD cast||1993-09-25 17:22:00||49.1975 N, 12.74367 W||RV Belgica BG9322A|
|1271511||Water sample data||1993-09-25 17:57:00||49.1975 N, 12.74369 W||RV Belgica BG9322A|
|883742||CTD or STD cast||1993-09-25 19:55:00||49.23033 N, 12.794 W||RV Belgica BG9322A|
|1271523||Water sample data||1993-09-25 20:18:00||49.23031 N, 12.79403 W||RV Belgica BG9322A|
|914969||CTD or STD cast||1993-10-21 08:46:00||49.18667 N, 12.81967 W||RV Pelagia PE093|
|908153||CTD or STD cast||1994-01-05 13:06:00||49.18333 N, 12.81 W||FS Meteor M27_1|
|908165||CTD or STD cast||1994-01-05 16:47:00||49.17 N, 12.79167 W||FS Meteor M27_1|
|444369||Currents -subsurface Eulerian||1994-01-11 08:41:00||49.1883 N, 12.795 W||FS Meteor M27_1|
|444370||Currents -subsurface Eulerian||1994-01-11 08:55:00||49.1883 N, 12.795 W||FS Meteor M27_1|
|908233||CTD or STD cast||1994-01-11 17:01:00||49.21167 N, 12.88333 W||FS Meteor M27_1|
|887362||CTD or STD cast||1994-04-16 06:51:00||49.4215 N, 12.7765 W||RRS Charles Darwin CD85|
|887301||CTD or STD cast||1994-04-18 03:36:00||49.1445 N, 12.7865 W||RRS Charles Darwin CD85|
|887313||CTD or STD cast||1994-04-18 05:53:00||49.16517 N, 12.768 W||RRS Charles Darwin CD85|
|444321||Currents -subsurface Eulerian||1994-04-18 13:56:00||49.1865 N, 12.8194 W||RRS Charles Darwin CD85|
|444308||Currents -subsurface Eulerian||1994-04-18 14:04:00||49.1865 N, 12.8194 W||RRS Charles Darwin CD85|
|887325||CTD or STD cast||1994-04-18 21:15:00||49.133 N, 12.82217 W||RRS Charles Darwin CD85|
|974033||CTD or STD cast||1994-05-25 13:50:00||49.194 N, 12.745 W||RRS Charles Darwin CD86|
|1663773||Water sample data||1994-05-25 14:24:00||49.19405 N, 12.74502 W||RRS Charles Darwin CD86|
|910378||CTD or STD cast||1994-09-16 02:37:00||49.18333 N, 12.845 W||FS Meteor M30_1|
|442941||Currents -subsurface Eulerian||1994-09-16 13:10:00||49.1912 N, 12.8 W||FS Meteor M30_1|
|442928||Currents -subsurface Eulerian||1994-09-16 13:14:00||49.1912 N, 12.8 W||FS Meteor M30_1|
|885275||CTD or STD cast||1995-06-12 23:00:00||49.2025 N, 12.8185 W||RRS Charles Darwin CD94|
|915008||CTD or STD cast||1995-08-21 06:15:00||49.1865 N, 12.8195 W||RV Pelagia PE95A|
|915162||CTD or STD cast||1995-09-18 19:37:00||49.18983 N, 12.74183 W||RV Pelagia PE95B|
|886475||CTD or STD cast||1995-10-01 04:24:00||49.19567 N, 12.811 W||RRS Discovery D217|
|886358||CTD or STD cast||1995-10-05 05:00:00||49.1875 N, 12.80517 W||RRS Discovery D217|
|886371||CTD or STD cast||1995-10-05 11:37:00||49.191 N, 12.84267 W||RRS Discovery D217|
|1676280||Water sample data||1995-10-05 12:39:00||49.19099 N, 12.84267 W||RRS Discovery D217|
|886383||CTD or STD cast||1995-10-05 14:53:00||49.1955 N, 12.85833 W||RRS Discovery D217|
|1676292||Water sample data||1995-10-05 15:07:00||49.19553 N, 12.85834 W||RRS Discovery D217|
|886229||CTD or STD cast||1995-10-14 05:20:00||49.19217 N, 12.8065 W||RRS Discovery D217|
|1676359||Water sample data||1995-10-14 05:35:00||49.19215 N, 12.80656 W||RRS Discovery D217|