Metadata Report for BODC Series Reference Number 1043427
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
Metadata Summary
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Problem Reports
No Problem Report Found in the Database
Data Quality Report
Higher flash responses were reported for FOMINI01 and FMMAXI01 between 01/09/2007 19:01 - 05/09/2007 18:40 (see cruise report p71). End-users are advised to treat FOMINI01, FMMAXI01, FVFMMI01 and SIGPSII1 with caution over this period.
Data Access Policy
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."
Narrative Documents
Chelsea Technologies Group FASTtracka MKI FRRF
The FASTtracka is a Fast Repetition Rate Fluorometer (FRRF) designed to measure the variable fluorescence of marine phytoplankton. It can be deployed on its own or integrated in moorings, profiling systems or in towed applications.
The operation mode comprises a rapid series of high frequency flashes (200 kHz), which enable the measurement of the absorption cross section of photosystem II (PSII), the rate of electron transport and the level of photochemical quenching. A 16 MHz clock microcontroller monitors the digital acquisition of the stimulated fluorescence and the excitation flashes, while simultaneously measuring Photosynthetic Active Radiation (PAR). These concurrent measurements allow for estimates of phytoplankton primary productivity to be made.
A comparison of ambient-irradiated and dark adapted phytoplankton samples is possible due to the optical head dual (light and dark) chamber design. All measurements are stored on an internal memory card with a 24 MB capacity and are downloaded through an RS232 connector.
Additional specifications include a maximum depth rating of 500 m and a chlorophyll-a sensitivity of 0.1 to 30 µg l-1.
Further information can be found in the manufacturer's specification sheet or the user guide.
Instrument Description
The Chelsea Technologies Group (CTG) FASTtracka TM I Fast Repetition Rate Fluorometer (FRRf) was connected to the ship's non-toxic supply within the bottle annex. Non-toxic seawater was pumped from a pick-up depth of approx. 5 m. The sensor was operated in flow-through mode. The manufacturer's calibration values for this instrument (Serial no. 05 5335 001) was 532.70 x 1010 quanta m-2 count-1 (30 Oct 2006).
Originator's Data Processing
Sampling Strategy
The Fast Repetition Rate Fluorometer (FRRf) was run between the 24/08/2007 17:59:35 to the 07/09/2007 14:59:02. The data were stored internally on the instrument and downloaded at between 1-3 day intervals.
Data Acquisition and Processing
Variable fluorescence was measured and processed in a similar manner to that described by Moore et al. (2005). Saturation of the variable chlorophyll fluorescence was performed using 100 flashlets of 1.1 µs duration with a 2.3 µs repetition rate. Subsequent relaxation of fluorescence was monitored using flashlets provided at 9.8 µs spacing, giving a total relaxation protocol length of around 2 ms. Data were not blank-corrected.
Table 1. Chelsea FASTtracka TM I gain settings
| Originator's ID | Start date/time | End date/time | Gain |
| UW22 | 24/08/2007 17:44 | 25/08/2007 16:07 | 1 |
| UW23 | 25/08/2007 16:27 | 26/08/2007 17:11 | 1 |
| UW24 | 26/08/2007 17:22 | 27/08/2007 18:28 | 1 |
| UW25 | 27/08/2007 18:41 | 28/08/2007 15:37 | 4 |
| UW26 | 28/08/2007 15:58 | 29/08/2007 23:04 | 4 |
| UW27 | 29/08/2007 23:17 | 30/08/2007 16:18 | 1 |
| UW28 | 30/08/2007 16:28 | 31/08/2007 15:42 | 1 |
| UW29 | 31/08/2007 15:54 | 01/09/2007 18:52 | 1 |
| UW30 | 01/09/2007 19:01 | 02/09/2007 14:52 | 1 |
| UW31 | 02/09/2007 15:08 | 03/09/2007 18:42 | 1 |
| UW32 | 03/09/2007 19:31 | 04/09/2007 17:11 | 1 |
| UW33 | 04/09/2007 17:24 | 05/09/2007 18:40 | 1 |
| UW34 | 05/09/2007 18:47 | 06/09/2007 17:14 | 1 |
| UW35 | 06/09/2007 17:20 | 07/09/2007 15:06 | 1 |
References Cited
Moore, C.M., Lucas, M.I., Sanders, S., and Davidson, R., 2005. Basin-scale variability of phytoplankton bio-optical characteristics in relation to bloom state and community structure in the Northeast Atlantic. Deep-Sea Research I 52:401-419
Processing at BODC
The data arrived at BODC in one Microsoft Excel file representing all of the processed measurements collected during cruises D321 and D321B (raw binary files were also received and are available on request). The Excel file was reformatted to two internal NetCDF format files (one for each cruise) using BODC generated code. The following table shows how the variables within the Excel file were mapped to appropriate BODC parameter codes:
| Originator's variable | Units | Description | BODC code | Units | Comments |
| Jday | day fractions | Julian day from the beginning of the year (0/0/2007 00:00:00) | - | - | Converted to BODC format |
| Long | decimal degrees | Longitude East | ALONGP01 | decimal degrees | |
| Lat | decimal degrees | Latitude North | ALATGP01 | decimal degrees | |
| Fo | arbitrary units | Minimal Fuorescence yields measured in the dark | FOMINI01 | not specified | |
| Fm | arbitrary units | Maximal Fuorescence yields measured in the dark | FMMAXI01 | not specified | |
| Fv/Fm | ratio | Maximum photochemical quantum efficiency in the dark | FVFMMI01 | dimensionless | |
| Sigma | x10-20 m-2* | Functional absorption cross-section of PSII in the dark | SIGPSII1 | Angstroms squared quanta-1 | x10-20 m-2 = 1 Angstrom squared |
*units were confirmed with originator as per quanta
The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.
Project Information
Oceans 2025 - The NERC Marine Centres' Strategic Research Programme 2007-2012
Who funds the programme?
The Natural Environment Research Council (NERC) funds the Oceans 2025 programme, which was originally planned in the context of NERC's 2002-2007 strategy and later realigned to NERC's subsequent strategy (Next Generation Science for Planet Earth; NERC 2007).
Who is involved in the programme?
The Oceans 2025 programme was designed by and is to be implemented through seven leading UK marine centres. The marine centres work together in coordination and are also supported by cooperation and input from government bodies, universities and other partners. The seven marine centres are:
- National Oceanography Centre, Southampton (NOCS)
- Plymouth Marine Laboratory (PML)
- Marine Biological Association (MBA)
- Sir Alister Hardy Foundation for Marine Science (SAHFOS)
- Proudman Oceanographic Laboratory (POL)
- Scottish Association for Marine Science (SAMS)
- Sea Mammal Research Unit (SMRU)
Oceans2025 provides funding to three national marine facilities, which provide services to the wider UK marine community, in addition to the Oceans 2025 community. These facilities are:
- British Oceanographic Data Centre (BODC), hosted at POL
- Permanent Service for Mean Sea Level (PSMSL), hosted at POL
- Culture Collection of Algae and Protozoa (CCAP), hosted at SAMS
The NERC-run Strategic Ocean Funding Initiative (SOFI) provides additional support to the programme by funding additional research projects and studentships that closely complement the Oceans 2025 programme, primarily through universities.
What is the programme about?
Oceans 2025 sets out to address some key challenges that face the UK as a result of a changing marine environment. The research funded through the programme sets out to increase understanding of the size, nature and impacts of these changes, with the aim to:
- improve knowledge of how the seas behave, not just now but in the future;
- help assess what that might mean for the Earth system and for society;
- assist in developing sustainable solutions for the management of marine resources for future generations;
- enhance the research capabilities and facilities available for UK marine science.
In order to address these aims there are nine science themes supported by the Oceans 2025 programme:
- Climate, circulation and sea level (Theme 1)
- Marine biogeochemical cycles (Theme 2)
- Shelf and coastal processes (Theme 3)
- Biodiversity and ecosystem functioning (Theme 4)
- Continental margins and deep ocean (Theme 5)
- Sustainable marine resources (Theme 6)
- Technology development (Theme 8)
- Next generation ocean prediction (Theme 9)
- Integration of sustained observations in the marine environment (Theme 10)
In the original programme proposal there was a theme on health and human impacts (Theme 7). The elements of this Theme have subsequently been included in Themes 3 and 9.
When is the programme active?
The programme started in April 2007 with funding for 5 years.
Brief summary of the programme fieldwork/data
Programme fieldwork and data collection are to be achieved through:
- physical, biological and chemical parameters sampling throughout the North and South Atlantic during collaborative research cruises aboard NERC's research vessels RRS Discovery, RRS James Cook and RRS James Clark Ross;
- the Continuous Plankton Recorder being deployed by SAHFOS in the North Atlantic and North Pacific on 'ships of opportunity';
- physical parameters measured and relayed in near real-time by fixed moorings and ARGO floats;
- coastal and shelf sea observatory data (Liverpool Bay Coastal Observatory (LBCO) and Western Channel Observatory (WCO)) using the RV Prince Madog and RV Quest.
The data is to be fed into models for validation and future projections. Greater detail can be found in the Theme documents.
Oceans 2025 Theme 10
Oceans 2025 is a strategic marine science programme, bringing marine researchers together to increase people's knowledge of the marine environment so that they are better able to protect it for future generations.
Theme 10: Integration of Sustained Observations in the Marine Environment spans all marine domains from the sea-shore to the global ocean, providing data and knowledge on a wide range of ecosystem properties and processes (from ocean circulation to biodiversity) that are critical to understanding Earth system behaviour and identifying change. They have been developed not merely to provide long-term data sets, but to capture extreme or episodic events, and play a key role in the initialisation and validation of models. Many of these SOs will be integrated into the newly developing UK Marine Monitoring Strategy - evolving from the Defra reports Safeguarding our Seas (2002) and Charting Progress (2005), thus contributing to the underpinning knowledge for national marine stewardship. They will also contribute to the UK GOOS Strategic Plan (IACMST, 2006) and the Global Marine Assessment.
Weblink: http://www.oceans2025.org/
Oceans 2025 Theme 10, Sustained Observation Activity 4: The Extended Ellett Line
The Ellett Line (begun in 1975 and since 1996 the Extended Ellett Line from Scotland to Iceland) crosses important north Atlantic Meridional Overturning Circulation (MOC) components and thus provides an additional contribution to understanding the north Atlantic response to climate change. Sustained Observation Activity (SO) 4 will repeat this section annually collecting a wide variety of physical and biogeochemical measurements, and will, to enhance the time variable component, make use of Argo floats and gliders. SO 4 will be implemented by physical, biological and chemical scientists at the National Oceanography Centre, Southampton (NOCS) and the Scottish Association for Marine Science (SAMS).
SO 4 formally contributes to the Department for Environment, Food and Rural Affairs (DEFRA)-funded Marine Environmental Change Network (MECN). Established in 2002 to coordinate and promote the collection and utilisation of marine time-series and long-term data sets, the goal of the network is to use long-term marine environmental data from around the British Isles and Ireland to separate natural fluctuations from global, regional and local anthropogenic impacts.
The specific deliverables for SO 4 are:
- A time series of the evolution of the hydrography of the northeast Atlantic, together with a more formal understanding of the causes of any changes observed
- An archived data set available to the international community via the British Oceanographic Data Centre (BODC)
- A platform for further scientific research
More detailed information on this Work Package is available at pages 15 - 16 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10
Weblink: http://www.oceans2025.org/
Oceans 2025 Theme 2: Marine Biogeochemical Cycles
Marine biogeochemical cycles are the key processes that control the cycling of climate-active gases within the surface ocean; the main transport mechanisms governing the supply of nutrients from deeper waters across the pycnocline; and the flux of material to deep water via the biological carbon pump. The broad aim of this Theme is to improve knowledge of major biogeochemical processes in the surface layer of the Atlantic Ocean and UK shelf seas in order to develop accurate models of these systems. This strategic research will result in predictions of how the ocean will respond to, and either ameliorate or worsen, climate change and ocean acidification.
Theme 2 comprises three Research Units and ten Work Packages. Theme 2 addresses the following pivotal biogeochemical pathways and processes:
- The oceans and shelf seas as a source and sink of climate-active gases
- The importance of the carbon and nitrogen cycles in the regulation of microbial communities and hence export and biogenic gas cycling
- The biological pump and export of carbon into the ocean's interior
- Processes that introduce nutrients into the euphotic zone
- The direct impact of a high CO2 world (acidification) on mixed-layer biogeochemical cycles and feedbacks to the atmosphere via sea/air gas fluxes and the biological pump
- The indirect impact of a high CO2 world (increased stratification and storminess) on the supply of nutrients to the surface layer of the ocean and hence on the biological carbon pump and air-sea gas fluxes
- Cellular processes that mediate calcification in coccolithophores and how these are impacted by environmental change with a focus on elevated CO2 and ocean acidification
- Inter- and intra-specific genetic diversity and inter-specific physiological plasticity in coccolithophores and the consequences of rapid environmental change
The official Oceans 2025 documentation for this Theme can be found using the following link: Oceans 2025 Theme 2
Oceans 2025 Theme 2, Work Package 2.6: Plankton Communities and Biogeochemistry
The focus of this Work Package is to gain a better understanding of the ocean's biological carbon pump (OBP), an important process in the global carbon cycle. Small changes in its magnitude resulting from climate change could have significant effects, both on the ocean's ability to sequester CO2 and on the natural flux of marine carbon. The impact of climatic forcing on plankton in different regions is complex with poorly understood consequences for the OBP. However, there is growing evidence that both high and low latitude ecosystems are particularly susceptible to change. In the subpolar Atlantic, the biogeochemical paradigm is one of diatom-dominated spring blooms initiated by NO3 and Si concentrations set by winter overturning, which drive carbon export. But by late spring and early summer, nutrient limitation and grazing pressure shift phytoplankton community structure towards dinoflagellates and sometimes massive coccolithophore blooms characterised by calcification rather than silicification processes. High residual nitrate concentrations and low chlorophyll levels in the Irminger basin in late summer away from coastal margins suggest potential iron control over phytoplankton growth. But it is possible that grazing or light limitation may be responsible for the residual summer nitrate pool. The iron limitation, grazing and light hypotheses will be tested in the high-latitude North Atlantic, including the Irminger basin. In addition, the factors controlling the transition to calcareous and non-mineralising organisms will be examined as calcite may be important in downwards organic carbon export via the ballast effect.
Low-latitude oligotrophic subtropical gyres form the world's largest biomes. Covering a third of the Earth's surface, they are dominated by microbial communities that turn over nutrients rapidly in strongly stratified, nutrient-poor surface waters. Low nutrient levels make these systems finely balanced with considerable potential for change. In the North Pacific gyre, recent changes have strengthened stratification, favouring N2 fixation. This increases the nitrogen pool, with the system becoming increasingly P limited. In the NASG, the potential for P limitation is now thought to be higher than that in the Pacific. In the two Atlantic gyres, P concentrations are dramatically different. The supply of nutrients to the mixed layer could be attributed to vertical as well as horizontal advection. The latter could be important in establishing the availability of nutrients.
This Work Package will be primarily coordinated by the National Oceanography Centre, Southampton (NOC). The NOC aims to assess the response of the two Atlantic gyre systems (NASG and SASG), by comparing their C, N, P and Fe nutrient fluxes and associated biogeochemistry including export and biogases, together with an assessment of the contribution of these biomes to the global OBP
Specific objectives are:
- To evaluate grazing, light and iron limitation as causes of the residual summer nitrate pool in the high-latitude North Atlantic
- To investigate the difference in P dynamics and export between the NASG and SASG - in particular the influence of advection and dust iron controls
- To provide estimates of spatial variability up to a biome scale of planktonic populations and biogeochemical processes related to the above hypotheses
- To examine the above hypotheses using ecosystem, HOPS and NEMO models
Aspects of this work will link to Oceans 2025 Theme 9 and 10, and Theme 2 WP 2.7
More detailed information on this Work Package is available from pages 15-17 of the official Oceans 2025 Theme 2 document: Oceans 2025 Theme 2
Weblink: http://www.oceans2025.org/
Data Activity or Cruise Information
Cruise
| Cruise Name | D321B |
| Departure Date | 2007-08-24 |
| Arrival Date | 2007-09-09 |
| Principal Scientist(s) | Toby J Sherwin (Scottish Association for Marine Science) |
| Ship | RRS Discovery |
Complete Cruise Metadata Report is available here
Fixed Station Information
Fixed Station Information
| Station Name | Extended Ellett Line |
| Category | Offshore route/traverse |
Extended Ellett Line
The Extended Ellett Line is a hydrographic transect consisting of 58 individual fixed stations which have been occupied, typically on an annual basis, since September 1996. The Line runs from the south of Iceland, across the Iceland Basin to the outcrop of Rockall, and across the Rockall Trough to the north west coast of Scotland (see map). CTD dips and associated water sampling for the analysis of nutrients are routinely performed during each station occupation.
The Extended Ellett Line augments the original Ellett Line time series - a shorter repeated transect which encompassed those stations between Rockall and Scotland. Work on the Ellett Line was typically carried out at least once a year between 1975 and 1996.
Map of standard stations (1996-present)
Map produced using the GEBCO Digital Atlas
The white triangles indicate the nominal positions of the Extended Ellett Line stations visited since September 1996. Measurements made along the Extended Ellett Line lie within a box bounded by co-ordinates 56° N, 21° W at the south west corner and 65° N, 6° W at the north east corner.
Nominal Extended Ellett Line stations (September 1996-present)
Listed below are nominal details of the standard hydrographic stations that have formed the Extended Ellett Line since September 1996.
| Station | Latitude | Longitude | Depth | Range |
|---|---|---|---|---|
| IB23S | 63.318 N | 20.210 W | 125 m | - |
| IB22S | 63.217 N | 20.067 W | 660 m | 0.0 nm |
| IB21S | 63.133 N | 19.917 W | 1030 m | 6.5 nm |
| IB20S | 62.917 N | 19.550 W | 1415 m | 16.4 nm |
| IB19S | 62.667 N | 19.667 W | 1500 m | 16.0 nm |
| IB18S | 62.333 N | 19.833 W | 1800 m | 16.0 nm |
| IB17 | 62.000 N | 20.000 W | 1700 m | 20.6 nm |
| IB16 | 61.500 N | 20.000 W | 2000 m | 30.1 nm |
| IB15 | 61.250 N | 20.000 W | 2375 m | 15.0 nm |
| IB14 | 61.000 N | 20.000 W | 2400 m | 15.0 nm |
| IB13 | 60.500 N | 20.000 W | 2500 m | 30.1 nm |
| IB12 | 60.000 N | 20.000 W | 2700 m | 30.1 nm |
| IB11 | 59.667 N | 19.117 W | 2680 m | 33.3 nm |
| IB10 | 59.400 N | 18.417 W | 2420 m | 26.7 nm |
| IB9 | 59.333 N | 18.233 W | 1910 m | 6.9 nm |
| IB8 | 59.200 N | 17.883 W | 1540 m | 13.4 nm |
| IB7 | 59.117 N | 17.667 W | 1000 m | 8.3 nm |
| IB6 | 58.950 N | 17.183 W | 850 m | 18.0 nm |
| IB5 | 58.883 N | 17.000 W | 1150 m | 7.0 nm |
| IB4 | 58.500 N | 16.000 W | 1210 m | 38.8 nm |
| IB3 | 58.250 N | 15.333 W | 680 m | 25.8 nm |
| IB2 | 57.950 N | 14.583 W | 480 m | 29.9 nm |
| IB1 | 57.667 N | 13.900 W | 160 m | 27.7 nm |
| A | 57.583 N | 13.633 W | 130 m | 10.0 nm |
| B | 57.567 N | 13.333 W | 210 m | 9.7 nm |
| C | 57.550 N | 13.000 W | 330 m | 10.8 nm |
| D | 57.542 N | 12.867 W | 1000 m | 4.3 nm |
| E | 57.533 N | 12.633 W | 1658 m | 7.6 nm |
| F | 57.508 N | 12.250 W | 1817 m | 12.5 nm |
| G | 57.492 N | 11.850 W | 1812 m | 13.0 nm |
| H | 57.483 N | 11.533 W | 2020 m | 10.3 nm |
| I | 57.467 N | 11.317 W | 750 m | 7.0 nm |
| J | 57.450 N | 11.083 W | 550 m | 7.6 nm |
| K | 57.400 N | 10.867 W | 850 m | 7.6 nm |
| L | 57.367 N | 10.667 W | 2076 m | 6.8 nm |
| M | 57.300 N | 10.383 W | 2340 m | 10.1 nm |
| N | 57.233 N | 10.050 W | 2100 m | 11.5 nm |
| O | 57.150 N | 9.700 W | 1900 m | 12.4 nm |
| P | 57.100 N | 9.417 W | 1050 m | 9.7 nm |
| Q | 57.050 N | 9.217 W | 350 m | 7.2 nm |
| R | 57.000 N | 9.000 W | 135 m | 7.7 nm |
| S | 56.950 N | 8.783 W | 125 m | 7.7 nm |
| 15G | 56.883 N | 8.500 W | 125 m | 10.1 nm |
| T | 56.837 N | 8.333 W | 120 m | 6.1 nm |
| 14G | 56.808 N | 8.167 W | 115 m | 5.7 nm |
| 13G | 56.783 N | 8.000 W | 110 m | 5.7 nm |
| 12G | 56.758 N | 7.833 W | 80 m | 5.7 nm |
| 11G | 56.733 N | 7.667 W | 55 m | 5.7 nm |
| 10G | 56.733 N | 7.500 W | 220 m | 5.5 nm |
| 9G | 56.733 N | 7.333 W | 160 m | 5.5 nm |
| 8G | 56.733 N | 7.167 W | 175 m | 5.5 nm |
| 7G | 56.733 N | 7.000 W | 145 m | 5.5 nm |
| 6G | 56.733 N | 6.750 W | 35 m | 8.2 nm |
| 5G | 56.733 N | 6.600 W | 75 m | 4.9 nm |
| 4G | 56.733 N | 6.450 W | 115 m | 4.9 nm |
| 3G | 56.708 N | 6.367 W | 75 m | 3.1 nm |
| 2G | 56.683 N | 6.283 W | 40 m | 3.2 nm |
| 1G | 56.667 N | 6.133 W | 190 m | 5.0 nm |
Occupations of the Extended Ellett Line (September 1996-present)
| BODC Cruise Identifier | Cruise Dates | Ship |
|---|---|---|
| D223A | 28 September-21 October 1996 | RRS Discovery |
| D230 | 7 August-17 September 1997 | RRS Discovery |
| D233 | 23 April-1 June 1998 | RRS Discovery |
| D242 | 7 September-6 October 1999 | RRS Discovery |
| D245 * | 27 January-20 February 2000 | RRS Discovery |
| 0700S * | 8-22 May 2000 | FRV Scotia |
| D253 | 4 May-20 June 2001 | RRS Discovery |
| 0703S * | 15 April-5 May 2003 | FRV Scotia |
| PO300_2 * | 19 July-6 August 2003 | RRS Poseidon |
| PO314 | 11 July-23 July 2004 | RV Poseidon |
| CD176 | 6 October-1 November 2005 | RRS Charles Darwin |
| D312 | 11-31 October 2006 | RRS Discovery |
| D321A | 24 July-23 August 2007 | RRS Discovery |
| D321B | 24 August-9 September 2007 | RRS Discovery |
| 0508S * | 6-25 May 2008 | FRV Scotia |
| D340A | 10-25 June 2009 | RRS Discovery |
| D351 | 10-28 May 2010 | RRS Discovery |
| D365 | 13 May-02 June 2011 | RRS Discovery |
* These cruises only surveyed the original hydrographic section between Scotland and Rockall.
Other Series linked to this Fixed Station for this cruise - 847243 847255 847267 847279 847280 847292 847311 847335 847347 847359 847360 847372 847384 847396 847403 847415 847427 847439 847440 847452 847464 847476 847488 847507 847519 847520 847532 847544 847556 847568 847612 847624 847636 847648 847661 847845 847857 847869 847870 847882 847894 974580 974592 974611 974623 974635 974647 974659 974660 974672 974684 1015463 1015475 1015487 1015499 1015506 1015518 1015531
Other Cruises linked to this Fixed Station (with the number of series) - 0508S (29) 0700S (20) 0703S (20) CD176 (40) D233 (25) D242 (45) D245 (25) D312 (51) D321 (D321A) (12) D321B (58) D340A (58) D351 (23) PO300_2 (31)
Fixed Station Information
| Station Name | Ellett Line |
| Category | Offshore route/traverse |
Ellett Line
The Ellett Line is a hydrographic transect consisting of 35 individual fixed stations which were occupied, usually at least once a year, between 1975 and 1996. The time series is named after the scientist David Ellett, who coordinated the survey work at Dunstaffnage Marine Laboratory (DML), near Oban. The transect ran between the north west coast of Scotland to the small outcrop of Rockall, via the Anton Dohrn Seamount - a prominent bathymetric feature in the Rockall Trough (see map). STD/CTD dips and associated water sampling for the analysis of nutrients were routinely performed during each station occupation.
In 1996 the transect was lengthened to incorporate new additional fixed stations crossing the Iceland Basin from Rockall to Iceland. This transect, which is still routinely occupied annually, is now known as the Extended Ellett Line and is a collaborative effort between scientists at Dunstaffnage Marine Laboratory and the Southampton site of the National Oceanography Centre (NOC).
Map of standard stations (1975-1996)
Map produced using the GEBCO Digital Atlas
The white triangles indicate the nominal positions of the Ellett Line stations (1975- 1996). Measurements made along the Ellett Line lie within a box bounded by co-ordinates 56° 40.02' N, 13° 42.0' W at the south west corner and 57° 37.2' N, 6° 7.98' W at the north east corner.
Nominal Ellett Line stations (1975-1996)
Listed below are nominal details of the standard hydrographic stations that formed the Ellett Line between 1975 and January 1996.
| Station | Latitude | Longitude | Depth | Range |
|---|---|---|---|---|
| A | 57.583 N | 13.633 W | 130 m | 10.0 nm |
| B | 57.567 N | 13.333 W | 210 m | 9.7 nm |
| C | 57.550 N | 13.000 W | 330 m | 10.8 nm |
| D | 57.542 N | 12.867 W | 1000 m | 4.3 nm |
| E | 57.533 N | 12.633 W | 1658 m | 7.6 nm |
| F | 57.508 N | 12.250 W | 1817 m | 12.5 nm |
| G | 57.492 N | 11.850 W | 1812 m | 13.0 nm |
| H | 57.483 N | 11.533 W | 2020 m | 10.3 nm |
| I | 57.467 N | 11.317 W | 750 m | 7.0 nm |
| J | 57.450 N | 11.083 W | 550 m | 7.6 nm |
| K | 57.400 N | 10.867 W | 850 m | 7.6 nm |
| L | 57.367 N | 10.667 W | 2076 m | 6.8 nm |
| M | 57.300 N | 10.383 W | 2340 m | 10.1 nm |
| N | 57.233 N | 10.050 W | 2100 m | 11.5 nm |
| O | 57.150 N | 9.700 W | 1900 m | 12.4 nm |
| P | 57.100 N | 9.417 W | 1050 m | 9.7 nm |
| Q | 57.050 N | 9.217 W | 350 m | 7.2 nm |
| R | 57.000 N | 9.000 W | 135 m | 7.7 nm |
| S | 56.950 N | 8.783 W | 125 m | 7.7 nm |
| 15G | 56.883 N | 8.500 W | 125 m | 10.1 nm |
| T | 56.837 N | 8.333 W | 120 m | 6.1 nm |
| 14G | 56.808 N | 8.167 W | 115 m | 5.7 nm |
| 13G | 56.783 N | 8.000 W | 110 m | 5.7 nm |
| 12G | 56.758 N | 7.833 W | 80 m | 5.7 nm |
| 11G | 56.733 N | 7.667 W | 55 m | 5.7 nm |
| 10G | 56.733 N | 7.500 W | 220 m | 5.5 nm |
| 9G | 56.733 N | 7.333 W | 160 m | 5.5 nm |
| 8G | 56.733 N | 7.167 W | 175 m | 5.5 nm |
| 7G | 56.733 N | 7.000 W | 145 m | 5.5 nm |
| 6G | 56.733 N | 6.750 W | 35 m | 8.2 nm |
| 5G | 56.733 N | 6.600 W | 75 m | 4.9 nm |
| 4G | 56.733 N | 6.450 W | 115 m | 4.9 nm |
| 3G | 56.708 N | 6.367 W | 75 m | 3.1 nm |
| 2G | 56.683 N | 6.283 W | 40 m | 3.2 nm |
| 1G | 56.667 N | 6.133 W | 190 m | 5.0 nm |
History of Ellett Line occupations (1975-January 1996)
| BODC Cruise Identifier | Cruise Dates | Ship |
|---|---|---|
| CH3/75 | 4-13 March 1975 | RRS Challenger |
| CH7A/75 | 1-6 May 1975 | RRS Challenger |
| CH10A/75 | 4-10 July 1975 | RRS Challenger |
| CH12A/75 | 26 August-2 September 1975 | RRS Challenger |
| CH14A/75 | 7-12 November 1975 | RRS Challenger |
| CH5A/76 | 29 March-5 April 1976 | RRS Challenger |
| CH8/76 | 19 May-1 June 1976 | RRS Challenger |
| CH12/76 | 4-15 August 1976 | RRS Challenger |
| CH15/76 | 7-16 October 1976 | RRS Challenger |
| CH17/76 | 7-20 December 1976 | RRS Challenger |
| CH4/77 | 25 February-11 March 1977 | RRS Challenger |
| CH6B/77 | 14-19 April 1977 | RRS Challenger |
| CH10/77 | 29 June-10 July 1977 | RRS Challenger |
| CH11/77 | 12-26 July 1977 | RRS Challenger |
| CH13/77 | 20 August-3 September 1977 | RRS Challenger |
| CH2/78 | 30 January-13 February 1978 | RRS Challenger |
| CH6/78 | 11-21 April 1978 | RRS Challenger |
| CH9/78 | 31 May-10 June 1978 | RRS Challenger |
| CH11B/78 | 29 July-12 August 1978 | RRS Challenger |
| CH11D/78 | 3-17 September 1978 | RRS Challenger |
| CH14B/78 | 4-11 November 1978 | RRS Challenger |
| CH7/79 | 10-23 May 1979 | RRS Challenger |
| S5/79 | 19 June-2 July 1979 | RRS Shackleton |
| CH13/79 | 11-16 September 1979 | RRS Challenger |
| CH16/79 | 28 October-11 November 1979 | RRS Challenger |
| CH4/80 | 26 February-7 March 1980 | RRS Challenger |
| CH7/80 | 21 April-6 May 1980 | RRS Challenger |
| CH2/81 | 26 January-4 February 1981 | RRS Challenger |
| CH6A/81 CH6B/81 | 6-25 April 1981 | RRS Challenger |
| CH10/81 | 4-14 July 1981 | RRS Challenger |
| CH15/81 | 6-20 October 1981 | RRS Challenger |
| CH7A/82 CH7B/82 | 26 April-16 May 1982 | RRS Challenger |
| CH15/82 | 16-30 October 1982 | RRS Challenger |
| CH7B/83 | 23 May-2 June 1983 | RRS Challenger |
| CH11/83 | 10-24 August 1983 | RRS Challenger |
| CH2/84 | 23 June-8 July 1984 | RRS Challenger |
| CH10/84 | 16 November-6 December 1984 | RRS Challenger |
| CH1/85 | 20 January-5 February 1985 | RRS Challenger |
| CH4/85 | 2-16 May 1985 | RRS Challenger |
| CH8/85 | 14-28 August 1985 | RRS Challenger |
| CH9 | 8-22 January 1987 | RRS Challenger |
| CH14 | 24 April-7 May 1987 | RRS Challenger |
| CH22 | 23 November-5 December 1987 | RRS Challenger |
| CH25 | 24 February-7 March 1988 | RRS Challenger |
| CH30 | 6-23 June 1988 | RRS Challenger |
| D180 | 20 January-4 February 1989 | RRS Discovery |
| LF1/89 | 5-11 May 1989 | RV Lough Foyle |
| LF2/89 | 4-10 August 1989 | RV Lough Foyle |
| CD44 | 24 November-2 December 1989 | RRS Charles Darwin |
| CH67A | 21-29 June 1990 | RRS Challenger |
| CH71A | 29 August-5 September 1990 | RRS Challenger |
| CH75B | 23 February-3 March 1991 | RRS Challenger |
| CH81 | 1-8 July 1991 | RRS Challenger |
| CH97 | 25 September-6 October 1992 | RRS Challenger |
| CH101B | 13-20 March 1993 | RRS Challenger |
| CH103 | 12-24 May 1993 | RRS Challenger |
| CH105 | 3-16 September 1993 | RRS Challenger |
| CH110 | 10-20 March 1994 | RRS Challenger |
| CH112 | 28 April-13 May 1994 | RRS Challenger |
| CH114 | 15-29 August 1994 | RRS Challenger |
| CH116 | 17-29 November 1994 | RRS Challenger |
| CD92B | 13 April-2 May 1995 | RRS Charles Darwin |
| CH120 | 18 July-6 August 1995 | RRS Challenger |
| CH124 | 8-27 January 1996 | RRS Challenger |
Other Series linked to this Fixed Station for this cruise - 847372 847384 847396 847403 847415 847427 847439 847440 847452 847464 847476 847488 847507 847519 847520 847532 847544 847556 847568 847612 847624 847636 847648 847661 847869 847870 847882 847894 974660 974672 974684 1015506 1015518 1015531
Other Cruises linked to this Fixed Station (with the number of series) - 0508S (29) 0700S (20) 0703S (20) CD176 (32) CD44 (34) CD92B (47) CH1/85 (19) CH10/77 (3) CH10/81 (21) CH10/84 (22) CH101B (13) CH103 (37) CH105 (34) CH10A/75 (15) CH11/77 (28) CH11/83 (35) CH110 (19) CH112 (35) CH114 (31) CH116 (25) CH11B/78 (26) CH11D/78 (14) CH120 (28) CH124 (32) CH12A/75 (3) CH13/77 (19) CH13/79 (17) CH14 (29) CH14A/75 (21) CH14B/78 (17) CH15/80 (8) CH15/81 (16) CH16/79 (13) CH2/78 (32) CH2/81 (13) CH2/82 (4) CH2/84 (29) CH22 (14) CH25 (18) CH3/83 (1) CH30 (23) CH4/77 (19) CH4/80 (29) CH4/85 (30) CH5A/76 (18) CH6/78 (25) CH63_2 (5) CH67A (27) CH6A/81 (14) CH6B/77 (24) CH6B/81 (20) CH7/79 (18) CH7/80 (16) CH71A (32) CH74A_1 (13) CH75B (31) CH7A/75 (24) CH7A/82 (24) CH7B/82 (13) CH7B/83 (29) CH8/76 (27) CH8/85 (30) CH81 (30) CH86B (8) CH89B (9) CH9 (25) CH9/78 (22) CH97 (30) CH9B/80 (10) D180 (30) D233 (10) D242 (23) D245 (25) D312 (34) D321B (34) D340A (34) D351 (34) DSK1/86 (10) FR13/85 (12) FR13/87 (2) FR14B/87 (2) FR18/87 (11) FR7B/86 (6) FR8/86 (13) LF1/89 (29) LF2/89 (30) PO300_2 (31) S5/79 (8)
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 |