Metadata Report for BODC Series Reference Number 1170912

• 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

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- Ocean Surveyor 150kHz Vessel mounted ADCP.

¹ Ranges at 1 to 5 knots ship speed are typical and vary with situation.
² Single-ping standard deviation.
³ User's choice of depth cell size is not limited to the typical values specified.

Profile Parameters

• Velocity long-term accuracy (typical): ±1.0%, ±0.5cm/s
• Velocity range: -5 to 9m/s
• # of depth cells: 1 - 128
• Max ping rate: 1.5

Bottom Track

Maximum altitude (precision <2cm/s): 600m

Echo Intensity Profile

Dynamic range: 80dB
Precision: ±1.5dB

Transducer & Hardware

Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W

Standard Sensors

Temperature (mounted on transducer)

• Range: -5° to 45°C
• Precision: ±0.1°C
• Resolution: 0.03°

Environmental

Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*

*later instruments have greater range.

Web Page

Further details can be found in the manufacturer's website or in the specification sheet.

BODC Processing

Data were received at BODC in 35 PSTAR format files.

The data were reformatted to the internal NetCDF format using BODC-generated Matlab code. The following table shows how the variables within the files were mapped to appropriate BODC parameter codes:

Following transfer the data were screened using BODC in-house visualisation software.

Data quality

There is a gap in the VM-ADCP data from approximately 09:25 until 16:27 on 7^th August 2009 and from approximately 05:25 until 07:17 on 9^th August 2009.

Instrument Description

150kHz ADCP

An RDI broad band 150 kHz (Ocean Surveyor) phased-array vessel-mounted Acoustic Doppler Current Profiler (VM-ADCP). The instrument is a broad-band phased array ADCP with 153.6 kHz frequency and a 30° beam angle.

The 150 kHz ADCP is mounted in the hull at a depth of 5.3 m.

Originator's Data Processing

Sampling strategy

The RDI Ocean Surveyor 150 kHz Phased Array VM-ADCP was configured to sample over 120 second intervals with 100 bins of 4m depth and a blank beyond transmit of distance of 4m.

Originators Data Processing

The deck unit had a firmware upgrade to VMDAS 23.17, after the March 2008 refit. The control PC ran RDI software VmDAS v1.46.

The VM-ADCP data were run through the following scripts:

• 150exec0: data read into Pstar format from RDI binary files. Water track velocities written into 'adp' files and bottom track into 'bot' files if in bottom track mode. Velocities were scaled to cm/s and amplitude by 0.45 to db. The time variable was corrected to GPS time by combining the PC clock time and the PC-GPS offset.
• s150exec1: data edited according to status flags (velocity data replaced with absent data if variable '2+bmbad' was greater than 25%); Time of ensemble moved to the end of ensemble period.
• s150exec2: merged data with Ashtech-a ghdg; ADCP velocities converted to speed and direction allowing heading correction to be applied; ADCP velocities returned to east and north components.
• s150exec3: applied misalignment angle ø and scaling factor A.
• s150exec4gp: merged ADCP data with the Trimble GPS 4000 navigation data. Ship's velocity calculated from spot positions and applied to ADCP velocity producing absolute velocity of the water; Time base of ADCP profiles shifted to the centre of the 2 minute ensemble by subtracting 60 seconds.

For further details on the processing please see the cruise report page 91.

Field Calibrations

A calibration of the 150 kHz VM-ADCP was achieved using bottom tracking data available from the transit through the Irish sea and across the continental shelf. Using long, straight, steady speed sections of standard two minute ensemble profiles over reasonably constant bottom depth the following calibrations for mis-alignment angle, Ø, and necessary amplification (tilt),A, were derived by comparing GPS derived component vectors of the vessel speed and direction with processed VM- ADCP bottom track determined component vectors of the vessel speed and direction:

Ø (misalignment angle) = 1.530827714 °
A (scaling factor) = 1.001707899

Further information on the calibration of the VM-ADCP can be found in the cruise reportpage 92.

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 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 2.5: Physical Processes and the Supply of Nutrients to the Euphotic Zone

The emphasis behind 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. This work package is concerned with the effect of physical processes and circulation on nutrient supply to the euphotic zone. Many physical pathways influence nutrient supply, such as winter overturning, Ekman pumping, small-scale turbulent mixing and mesoscale ageostrophic circulations, (of which, eddy pumping is but one example). Increased stratification will change patterns of winter overturning and dampen small-scale mixing. Shifts in wind patterns will perturb Ekman pumping. Changes in gradients of ocean heating and wind-forcing will alter the distribution of potential energy released through baroclinic instability of eddies and fronts. The combined effect of change on total nutrient supply will therefore be complex. Such physically-mediated changes, coupled to changes in aeolian dust deposition, may profoundly alter upper ocean plankton communities, biogeochemical cycling and carbon export.

This Work Package will be primarily coordinated by the National Oceanography Centre, Southampton (NOC). Specific objectives are:

• To determine the relative importance of mechanisms affecting nutrient supply to the photic zone by quantifying them in the three major biomes of the North Atlantic
• To establish how representative process studies are for the basin scale and thus define operators to scale up the individual process study results
• To determine the sensitivity to future climate change of the mechanisms sustaining total nutrient supply to the photic zone over the three major biomes of the North Atlantic

Aspects of this work will link to Oceans 2025 Theme 9 and 10, and Theme 2 WP 2.6.

More detailed information on this Work Package is available from pages 13-15 of the official Oceans 2025 Theme 2 document: Oceans 2025 Theme 2

Weblink: http://www.oceans2025.org/

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

Porcupine Abyssal Plain (PAP) Observatory

The Porcupine Abyssal Plain (PAP) observatory is a site at which moorings were deployed in the Northeastern Atlantic, as part of the ANIMATE (Atlantic Network of Interdisciplinary Moorings and Time-series for Europe), MERSEA (Marine Environment and Security for the European Area), EuroSITES, Oceans2025, Fix03 and CLASS projects. The PAP site is centred at latitude 49° N and longitude 16.5° W. Moorings have occupied this region since 2002 and are typically deployed for 12 months.

Please note: Near Real Time data is only stored at BODC where delayed mode data were not recovered. All near real time data can be found at the OceanSites GDA and through IFREMER.

Data summary

Status Indicators

Related Fixed Station activities are detailed in Appendix 1

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: Porcupine Abyssal Plain (PAP)

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.