Metadata Report for BODC Series Reference Number 1022030

• 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

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.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

Instrument Description

A 75 kHz Teledyne RDI Ocean Surveyor Vessel Mount Acoustic Doppler Current Profiler (ADCP). The instrument is located on the RRS James Cook port side retractable drop keel. When extended, the transducer depth is approximately 9.7 m below sea level.

RD Instruments- Ocean Surveyor 75kHz 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: 0.7

Bottom Track

Maximum altitude (precision <2cm/s): 950m

Echo Intensity Profile

Dynamic range: 80dB
Precision: ±1.5dB

Transducer and 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 on the manufacturer's website or in the specification sheet

Originator's Data Processing

ADCP Configuration

The 75 kHz Teledyne RDI Ocean Surveyor Vessel Mount ADCP was run in low resolution, long-range mode (narrowband) with 60 x 16 m bins (8 m blanking distance). For more information on configuration, see the cruise report, pages 90-91.

Data Processing

Data acquisition was performed in the Teledyne RDI Windows^TM-based software, VMDAS (Vessel-mount data acquisition system). Resulting binary ADCP data were processed and edited in University of Hawaii CODAS ADCP processing software. Further examination was performed using the NOCS-generated MEXEC processing suite of programs. Only data corresponding to when the drop keel was down were analysed. For more detailed information on processing, see the cruise report, pages 92-96.

Calibration

Calibration data were calculated using data from when bottom tracking was enabled and the drop keel was extended, and applied to all data where the drop keel was extended. The calibration data are shown below. For more detailed information on calibration see the cruise report, pages 97-100.

Processing at BODC

Data obtained using the 75 kHz Teledyne RDI Ocean Surveyor Vessel Mount Acoustic Doppler Current Profiler (ADCP) were received at BODC in NetCDF MSTAR format files. The data covered the span of the SR1 and SR1b transects through the Drake Passage in the Southern Ocean. The data received were processed in two different ways. Data were either calibrated and averaged into 5 min profiles covering the whole of each transect. This resulted in 2 NetCDF files - one for each transect. Alternatively, data were calibrated, split and averaged over each on/off CTD section. This resulted in 160 NetCDF files (1 file per section, 80 for each transect). After consulting the originators, it was decided that the 5 min profiled sections should be transferred into the BODC database because they provided the highest sampling resolution of each transect. However, on/off CTD section files will still be available in originators format upon requests.

The 5 min profile 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:

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 Theme 1: Climate, Ocean Circulation and Sea Level

Through fieldwork, analysis and modelling, Theme 1 will provide detailed knowledge of how the Atlantic, Arctic and Southern Oceans are responding to, and driving, climate change. In combination with geodetic studies, it will also improve our ability to predict global sea level and UK land movements in the century ahead.

The official Oceans 2025 documentation for this Theme is available from the following link: Oceans 2025 Theme 1

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

Oceans 2025 Theme 1, Work Package 1.3: Physical-biogeochemical budgets and mixing in the Southern Ocean

This Work Package is run by the National Oceanography Centre, Southampton (NOCS) and aims to establish regional budgets of heat, freshwater and carbon, and to develop more accurate parameterisations for predictive ocean models by quantitatively investigating diapycnal and isopycnal transport processes using observations.

Vast, though poorly quantified, amounts of anthropogenic CO2 (~20 Pg) are believed to have been absorbed into the Antarctic mode and intermediate waters. Much of this uptake is achieved in the Antarctic Circumpolar Current (ACC), involving the upwelling of North Atlantic Deep Water, its northward transport by a delicate balance between Ekman drift and eddies, followed by subduction as mode waters. Models suggest that the rate of CO2 uptake is sensitive to changes in the wind and to changes to the eddy fluxes (Mignone et al., 2005).

To predict climate change, it is essential that the size of this carbon sink be known, and the processes that control it be understood. Even the exchanges of heat and freshwater between the Atlantic and Southern Oceans are poorly known. NOCS will combine observations and modelling to quantify and understand the processes controlling property fluxes and trends in the Atlantic sector of the Southern Ocean, where the Atlantic overturning circulation is partially closed as it meets the ACC. The observational effort will be fully integrated with the international Climate Variability and Predictability (CLIVAR)/Carbon repeat hydrography program, and with the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) initiative to study mixing rates and processes; this work has been accepted as a contribution to the International Polar Year. The budgets and mixing rates inferred from field measurements will be used to both evaluate and improve numerical models.

More detailed information on this Work Package is available at pages 10 - 11 of the official Oceans 2025 Theme 1 document: Oceans 2025 Theme 1

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

References

Mignone B., Gnanadesikan A., Sarmiento JL., and Slater RD., 2005. Central role of Southern Hemisphere winds and eddies in modulating the oceanic uptake of anthropogenic carbon, Geophys Res Lett, 32 doi:101029/2005Gl024464

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.

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

World Ocean Circulation Experiment (WOCE) Southern Repeat Section 1 - South America to West Antarctic Peninsula

WOCE established a repeat hydrographic section across Drake Passage and designated it SR1 (also known as A21). The section is located between the Southern tip of South America and the West Antarctic Peninsula within a bounding box of 55° 19.40' S, 68° 15.80' W (North-Western corner) and 64° 8.52' S, 63° 4.80' W (South-Eastern corner).

In 1992 the section was moved eastwards to lie on a satellite ground track with the northern end on the south side of Burdwood Bank and the southern end off Elephant Island. This revised location was designated SR1b.

A table of cruises which occupied SR1 is presented below with links to the relevant cruise reports (where available).

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: Drake Passage - WOCE SR1

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.