Metadata Report for BODC Series Reference Number 1086114
On four occasions, there was a discrepancy between the date used to construct the data file name and the date and time logged in the raw data file. The data originator was consulted but was unable to confirm with 100% confidence which information was correct. For consistency with other Western Channel Observatory datasets collected at the L4 site, the date used in the file name was used as the date of sampling with a default sampling time of 10:00 UT but users should be aware that the date and time in the raw data files were as follows:
020107_L4 had a raw sensor date/time logged of 12 Dec 2001 09:42 UT.
020114_L4 had a raw sensor date/time logged of 19 Dec 2001 10:06 UT.
030902_L4 had a raw sensor date/time logged of 29 Aug 2003 14:17 UT.
050404_L4 had a raw sensor date/time logged of 01 Apr 2005 11:03 UT.
Data Quality Document
Temperature, salinity and sigma-theta:
On the whole the trends appear reasonable for the location and time of year that the casts were made. Casts which displayed unrealistic values for the location and time of the year have been flagged accordingly. Once in 2002, 2003 and 2008, entire profiles had to be flagged. A specific problem report has been created for these casts to highlight the problem. Users should be aware that the salinity channel was sometimes noisy, particularly close to the surface or in the vicinity of strong gradients. This was particularly strong in casts collected in 2005.
The fluorometer output which was labelled as a voltage channel in the originators' files was sometimes in excess of the maximum voltage of 4 volts specified in the manufacturer's specification sheet. Nevertheless the overall trends including occasional strong vertical variability appear reasonable given the location and time of year. However on four occasions in April and May 2002 the fluorescence vertical profiles showed very low values and unrealistically low variability with depth for the time or year and hydrographic conditions. These were deemed suspect and flagged accordingly by BODC.
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."
|Chelsea Technologies||MiniTracka II||07-6310-003|
Sea-Bird SBE 19 and SBE 19plus SEACAT Profiler CTDs
The SBE 19 SEACAT Profiler is a self-contained, battery powered, pumped CTD system designed to measure conductivity, temperature, and pressure in marine or fresh water environments to depths of 10,500 meters. It was replaced by the SBE 19plus model in 2001. An updated version of this instrument is the SBE 19plus V2, which incorporates an electronics upgrade and additional features, with six differentially amplified A/D input channels, one RS-232 data input channel, and 64 MB FLASH memory.
The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by titanium housing for depths up to 7000 m. It is typically used for CTD profiling although a conversion kit is available for mooring deployments. The CTD can also be attached to an SBE 36 CTD Deck Unit and Power/Data Interface Module (PDIM) for real-time operation on single-core armored cable up to 10,000 m.
|Parameter||SBE 19||SBE 19plus|
Range: -5 to +35 °C
Accuracy: 0.01 °C
Resolution: 0.001 °C
Calibration: +1 to +32 °C*
Range: -5 to +35 °C
Accuracy: 0.005 °C
Resolution: 0.0001 °C
Calibration: +1 to +32 °C*
Range: 0 to 7 S m-1 (0 to 70 mmho cm-1)
Accuracy: 0.001 S m-1
Resolution: 0.0001 S m-1
Calibration: 0 to 7 S m-1. Physical calibration over the range 1.4 - 6 S m-1*
Range: 0 to 9 Sm-1
Resolution: 0.00005 (most oceanic waters, resolves 0.4 ppm in salinity); 0.00007 (high salinity waters, resolves 0.4 ppm in salinity); 0.00001 (fresh waters, resolves 0.1 ppm in salinity)
Calibration: 0 to 9 S m-1. Physical calibration over the range 1.4 - 6 S m-1*
|Strain gauge pressure sensor|| |
Range: 0 to100, 150, 300, 500, 1000, 1500, 3000, 5000, 10000 or 15000 psia
Accuracy: 0.25% of full scale range (100 - 1500 psia); 0.15% of full scale range (3000 - 15000 psia)
Resolution: 0.015% of full scale
Calibration: 0 to full scale in 20% steps
Range: 0 to 20, 100, 350, 1000, 2000, 3500 or 7000 m
Accuracy: 0.1% of full scale range
Resolution: 0.002% of full scale range
Calibration: ambient pressure to full scale range in 5 steps
*Measurements outside this range may be at slightly reduced accuracy due to extrapolation errors.
Options and accessories
Additional sensors can be attached to the CTD, including:
- high accuracy Paroscientific Digiquartz pressure sensor (depth range 0 to 20, 60, 130, 200, 270, 680, 1400, 2000, 4200, 7000 or 10500 m; accuracy 0.02% of full scale; resolution 0.0025% of full scale)
- Dissolved Oxygen (SBE 43 DO Sensor)
- pH* (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor)
- radiance (PAR)
- light transmission
- optical backscatter (turbidity)
The standard SBE 5M pump may be replaced by an SBE 5P (plastic housing) or 5T (titanium housing) pump for use with dissolved oxygen and/or other pumped sensors. Further details can be found in the manufacturer's SBE 19plus V2 instrument specification or theSBE 19 andSBE 19 plus user guides.
Chelsea Instruments MINItracka Fluorometer
The MINItracka Fluorometer is an in-situ optical sensor that uses a single high intensity LED light source and, according to the manufacturer, is designed to enhance rejection of ambient daylight. The fluorometer provides a linear response between chlorophyll concentration and fluorometer voltage.
Sensor specifications, current at August 2006, are given in the table below. More information can be found at the manufacturer's specification sheet.
|Excitation wavelengths||430/30 nm||470/30 nm||470/30 nm||425/30 nm||480/80 nm|
|Emission wavelength||685/30 nm||685/30 nm||590/45 nm||550/30 nm||530/30 nm|
|Concentration range||0.03-100 µg l-1||0.03-100 µg l-1||0.03-100 µg l-1||0.04-200 µg l-1||0.03-100 µg l-1|
|Resolution||0.01 µg l-1||0.01 µg l-1||0.01 µg l-1||0.025 µg l-1||0.01 µg l-1|
|Calibration standard||Chlorophyll-a in acetone||Chlorophyll-a in acetone|
|Excitation wavelengths||470/30 nm||530/30 nm||590/35nm|
|Emission wavelength||470/30 nm||580/30 nm||645/35 nm|
|Concentration range||0.04-100 FTU||0.03-100 µg l-1||0.03-100 µg l-1|
|Resolution||0.01 FTU||0.01 µg l-1||0.01 µg l-1|
|Body Size||149 mm long x 70 mm dia||Input Voltage||7 to 40 VDC|
|Weight in Air||0.7 Kg||Output Voltage||0 to 4 VDC (linear)|
|Weight in Water||0.15 Kg||Power requirements||0.7 W typical|
|Depth Rating||600 m||Signal : Noise||10,000 : 1 @ full scale|
Originator's Sampling Strategy
These data were collected using a CTD rig deployed from PML research vessels.
The raw CTD data were processed using the Sea-Bird software. The data were provided in tab delimited format.
BODC post-processing and screening
The data were converted from tab delimited format into BODC internal format using BODC transfer function 401. During transfer the depth variable was converted to pressure using the routine 'sw_pres', a part of the Seawater toolbox, this used the method of Fofonoff and Millard Jr. (1983) using inputs of depth and latitude. The density parameter was not transferred by BODC as this is generated to a standard algorithm during BODC transfer.
The measured variables were mapped to BODC parameter codes shown in the table below:
|Originator's Parameter Name||Units||Description||BODC parameter code||Units||Comments|
|Tv290v||Deg C||Temperature of the water column||TEMPST01||Deg C||-|
|FlCM||volts||Raw fluorometer voltage||FVLTZZ01||volts||-|
|DepSM||m||Depth of the water column||DEPHPR01||m||-|
|Density00||kg m-3||Density of the water column by unknown algorithm||-||-||Channel not transferred as generated during BODC transfer|
|Sal00||-||Salinity of the water column||PSALST01||-||-|
|-||-||Pressure||PRESPR01||dbar||Calculated by BODC from depth and latitude|
|-||-||Sigma-theta||SIGTPR01||kg m-3||Generated by BODC using Fofonoff and Millard (1983) algorithm with parameters PRESPR01, TEMPST01 and PSALST01.|
Reformatted CTD data were transferred onto a graphics work station for visualisation using the in-house editor EDSERPLO. No data values were edited or deleted. Flagging was achieved by modification of the associated BODC quality control flag for suspect or null values.
The profiles were banked to the National Oceanographic Database (NODB) following BODC procedures.
Fofonoff, N.P. and Millard, R.C., 1983. Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science No. 44, 53pp.
Western Channel Observatory (2002-2007)
Who funded the programme?
The Natural Environment Research Council (NERC) through PML core funding.
Who was involved in the programme?
The programme was a collaboration involving scientists at Plymouth Marine Laboratory (PML) and the Marine Biological Association of the United Kingdom (MBA).
What was the programme about?
The Western Channel Observatory (WCO) is situated in the Western English Channel and comprises of long-term sustained observations at a number of stations. These stations have been the basis of a series of hydrographic surveys carried out during the 20th Century by scientists at the Marine Biological Association in Plymouth. Station L4 (50o 15' N, 4o 13' W) is one of these hydrographic stations and has been regularly sampled by the PML Zooplankton Group for a range of parameters from 1988 (the L4 time-series). Station E1 (50o 02' N, 4o 22' W) further offshore from Plymouth, has been the focus of a long time series of hydrographic and plankton observations and is where the concept of the "Russell Cycle" was developed. It had been regularly sampled until the late 1980s and in 2002 sampling recontinued for a range of parameters complementing those already being collect at the L4 station. The inclusion of the historic data sets from the E1 and L5 stations, in some cases dating back to the early 1900s, formed the basis for the Western Channel Observatory. The aim of the Western Channel Observatory (WCO) became to draw together long-term in situ measurements made at L4 and E1, ecosystem modelling studies and Earth Observation (EO), and integrate these using web-based Geographic Information System (GIS) technology. By integrating these quantitative in situ measurements, modelling studies and EO the WCO aimed to elucidate changes that are occurring in the marine component of the Earth system. The WCO is an ideal location as:
- it has a long history (>100 years) of in situ sampling at several stations;
- it represents both ocean influenced and coastal waters within 30 km of PML; and
- PML has recognised excellence in ecosystem modelling (ERSEM) and satellite remote sensing (Earth Observation - EO) science.
The observatory was further expanded between 2002 and 2007 to include measurements that had not been made before at these stations.
When was the programme active?
The observatory expanded from the L4 time-series with the resumption of sampling at E1 in 2002 in connection with MECN. In 2007 continued funding was provided for the WCO under the Oceans 2025 programme Theme 10: Integration of Sustained Observations in the Marine Environment.
Brief summary of the programme fieldwork/data
The programme continued the L4 time-series of weekly zooplankton and phytoplankton measurements at station L4 from 1988. Monthly sampling, which had stopped in the late 1980s, resumed in 2002 at station E1 for hydrography and phyoplankton data, and at stations E1 and L5 for zooplankton and fish larvae data. In addition new data sets of pigment and optics measurements at station E1 began in 2002 and the PML meterological station was set up in 2003.
|Principal Scientist(s)||Roger Harris (Plymouth Marine Laboratory)|
|Ship||Unknown research vessel|
Complete Cruise Metadata Report is available here
Fixed Station Information
|Station Name||Western Channel Observatory L4|
|Latitude||50° 15.00' N|
|Longitude||4° 13.02' W|
|Water depth below MSL||55.0 m|
Western Channel Observatory station L4
The Western Channel Observatory (WCO) is situated in the Western English Channel and comprises of long-term sustained observations at a number of stations.
Station L4 is located south-west of Plymouth at 50° 15.00 N, 4° 13.02 W.
More information can be found on the Western Channel Observatory website.
Other Cruises linked to this Fixed Station (with the number of series) - MS070903 (1) MS070910 (1) MS070917 (1) MS070928 (1) MS071002 (1) MS071008 (1) MS071025 (1) MS071030 (1) MS071105 (1) MS071112 (1) MS071122 (1) MS071126 (1) MS071211 (1) MS080213 (1) MS080220 (1) MS080227 (1) MS081208 (1) MS081215 (1) MS090105 (1) MS090316 (1) MS090421 (1) PML011212 (1) PML011219 (1) PML020715 (1) PML020807 (1) PML030311 (1) PML030321 (1) PML030327 (1) PML030402 (1) PML030409 (1) PML030507 (1) PML030513 (1) PML030605 (1) PML030612 (1) PML030620 (1) PML030701 (1) PML030703 (1) PML030730 (1) PML030801 (1) PML030829 (1) PML030917 (1) PML031027 (1) PML031110 (1) PML031124 (1) PML031210 (1) PML031215 (1) PML040121 (1) PML040216 (1) PML040301 (1) PML040308 (1) PML040317 (1) PML040329 (1) PML040413 (1) PML040422 (1) PML040426 (1) PML040510 (1) PML040517 (1) PML040524 (1) PML040602 (1) PML040607 (1) PML040614 (1) PML040621 (1) PML040630 (1) PML040706 (1) PML040721 (1) PML040802 (1) PML040816 (1) PML040825 (1) PML040831 (1) PML040906 (1) PML041018 (1) PML041026 (1) PML041101 (1) PML041109 (1) PML041116 (1) PML041123 (1) PML041129 (1) PML041206 (1) PML041213 (1) PML041220 (1) PML050106 (1) PML050124 (1) PML050131 (1) PML050215 (1) PML050222 (1) PML050228 (1) PML050307 (1) PML050315 (1) PML050321 (1) PML050329 (1) PML050411 (1) PML050426 (1) PML050504 (1) PML050509 (1) PML050516 (1) PML050525 (1) PML050601 (1) PML050606 (1) PML050613 (1) PML050620 (1) PML050627 (1) PML050704 (1) PML050711 (1) PML050725 (1) PML050801 (1) PML050808 (1) PML050815 (1) PML050830 (1) PML050905 (1) PML050912 (1) PML050919 (1) PML050926 (1) PML051003 (1) PML051010 (1) PML051017 (1) PML051115 (1) PML051122 (1) PML051128 (1) PML051205 (1) PML051212 (1) PML051219 (1) PML060103 (1) PML060109 (1) PML060116 (1) PML060123 (1) PML060202 (1) PML060206 (1) PML060213 (1) PML060227 (1) PML060306 (1) PML060315 (1) PML060320 (1) PML060329 (1) PML060403 (1) PML060504 (1) PML060508 (1) PML060523 (1) PML060606 (1) PML060612 (1) PML060620 (1) PML060627 (1) PML060703 (1) PML060710 (1) PML060807 (1) PML060814 (1) PML060829 (1) PML060904 (1) PML060912 (1) PML060925 (1) PML061003 (1) PML061030 (1) PML061106 (1) PML061218 (1) PML070122 (1) PML070129 (1) PML070205 (1) PML070320 (1) PML070326 (1) PQ070410 (1) PQ070416 (1) PQ070423 (1) PQ070430 (1) PQ070508 (1) PQ070521 (1) PQ070604 (1) PQ070611 (1) PQ070625 (1) PQ070703 (1) PQ070709 (1) PQ070716 (1) PQ070723 (1) PQ070730 (1) PQ070806 (1) PQ070813 (1) PQ070820 (1) PQ070828 (1) PQ080305 (1) PQ080317 (1) PQ080407 (1) PQ080414 (1) PQ080421 (1) PQ080428 (1) PQ080506 (1) PQ080512 (1) PQ080519 (1) PQ080528 (1) PQ080602 (1) PQ080609 (1) PQ080616 (1) PQ080623 (1) PQ080630 (1) PQ080714 (1) PQ080721 (1) PQ080728 (1) PQ080820 (1) PQ080826 (1) PQ080902 (1) PQ080915 (1) PQ080922 (1) PQ080929 (1) PQ081006 (1) PQ081013 (1) PQ081021 (1) PQ081103 (1) PQ090113 (1) PQ090121 (1) PQ090211 (1) PQ090216 (1) PQ090223 (1) PQ090302 (1) PQ090309 (1) PQ090323 (1) PQ090330 (1) PQ090406 (1) PQ090414 (1) PQ090514 (1) PQ090521 (1) PQ090602 (1) PQ090615 (1) PQ090622 (1) PQ090629 (1) PQ090707 (1) PQ090713 (1) PQ090720 (1) PQ090727 (1) PQ090811 (1) PQ090901 (1) PQ090907 (1) PQ090914 (1) PQ090922 (1) PQ090930 (1) PQ091007 (1) PQ091012 (1) PQ091019 (1) PQ091026 (1) PQ091109 (1) PQ091201 (1) PQ091209 (1) PQ091215 (1) PQ091221 (1) PQ100104 (1) PQ100111 (1) PQ100118 (1) PQ100126 (1) PQ100201 (1) PQ100215 (1) PQ100225 (1) PQ100301 (1) PQ100308 (1) PQ100315 (1) PQ100407 (1) PQ100412 (1) PQ100419 (1) PQ100426 (1) PQ100504 (1) PQ100510 (1) PQ100517 (1) PQ100524 (1) PQ100602 (1) PQ100607 (1) PQ100614 (1) PQ100621 (1) PQ100629 (1) PQ100706 (1) PQ100712 (1) PQ100719 (1) PQ100726 (1) PQ100803 (1) PQ100811 (1) PQ100816 (1) PQ100831 (1) PQ100906 (1) PQ100913 (1) PQ100920 (1) PQ100927 (1) PQ101004 (1) PQ101013 (1) PQ101018 (1) PQ101025 (1) PQ101101 (1) PQ101110 (1) PQ101116 (1) PQ101122 (1) PQ101130 (1) PQ101206 (1) PQ101213 (1) PQ101221 (1) PQ110106 (1) PQ110117 (1) PQ110125 (1) PQ110131 (1) PQ110208 (1) PQ110222 (1) PQ110228 (1) PQ110307 (1) PQ110314 (1) PQ110322 (1) PQ110328 (1) PQ110406 (1) PQ110411 (1) PQ110418 (1) PQ110426 (1) PQ110511 (1) PQ110516 (1) PQ110524 (1) PQ110601 (1) PQ110606 (1) PQ110614 (1) PQ110620 (1) PQ110627 (1) PQ110704 (1) PQ110711 (1) PQ110719 (1) PQ110725 (1) PQ110801 (1) PQ110808 (1) PQ110815 (1) PQ110822 (1) PQ110830 (1) PQ110915 (1) PQ110919 (1) PQ110926 (1) PQ111003 (1) PQ111012 (1) PQ111017 (1) PQ111025 (1) PQ111101 (1) PQ111108 (1) PQ111116 (1) PQ111121 (1) PQ111219 (1) PQ120109 (1) PQ120116 (1) PQ120123 (1) PQ120130 (1) PQ120207 (1) PQ120213 (1) PQ120220 (1) PQ120227 (1) PQ120306 (1) PQ120313 (1) PQ120319 (1) PQ120326 (1) PQ120402 (1) PQ120411 (1) PQ120416 (1) PQ120424 (1) PQ120501 (1) PQ120508 (1) PQ120514 (1) PQ120521 (1) PQ120523 (1) PQ120528 (1) PQ120611 (1) PQ120618 (1) PQ120625 (1) PQ120702 (1) PQ120709 (1) PQ120719 (1) PQ120723 (1) PQ120730 (1) PQ120806 (1) PQ120814 (1) PQ120820 (1) PQ120903 (1) PQ120910 (1) PQ120917 (1) PQ120926 (1) PQ121008 (1) PQ121015 (1) PQ121022 (1) PQ121030 (1) PQ121107 (1) PQ121114 (1) PQ121128 (1) PQ121205 (1) PQ121210 (1) PQ121218 (1) SEP020618 (1) SEP020624 (1) SEP020709 (1) SEP021203 (1) SEP030325 (1) SEP030331 (1) SEP030407 (1) SEP030422 (1) SEP030623 (1) SEP030811 (1) SEP030911 (1) SEP030915 (1) SEP030924 (1) SEP030929 (1) SEP031021 (1) SEP031106 (1) SQ020212 (1) SQ020304 (1) SQ020402 (1) SQ020415 (1) SQ020422 (1) SQ020501 (1) SQ020507 (1) SQ020516 (1) SQ020527 (1) SQ020611 (1) SQ020701 (1) SQ020722 (1) SQ020729 (1) SQ020805 (1) SQ020812 (1) SQ020828 (1) SQ020902 (1) SQ020909 (1) SQ020916 (1) SQ020930 (1) SQ021007 (1) SQ021014 (1) SQ021028 (1) SQ021104 (1) SQ021118 (1) SQ021125 (1) SQ030106 (1) SQ030113 (1) SQ030122 (1) SQ030127 (1) SQ030203 (1) SQ030210 (1) SQ030217 (1) SQ030317 (1) SQ030414 (1) SQ030512 (1) SQ030519 (1) SQ030528 (1) SQ030602 (1) SQ030609 (1) SQ030616 (1) SQ030630 (1) SQ030707 (1) SQ030714 (1) SQ030721 (1) SQ030728 (1) SQ030804 (1) SQ030820 (1) SQ030827 (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|