Metadata Report for BODC Series Reference Number 932097

• 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

SeaBird Digital Oceanographic Thermometer SBE38

The SBE38 is an ultra-stable thermistor that can be integrated as a remote temperature sensor with an SBE21 Thermosalinograph or an SBE 45 Micro TSG, or as a secondary temperature sensor with an SBE 16 plus, 16plus-IM, 16plus V2, 16plus-IM V2 or 19plus V2 SEACAT CTD.

Temperature is determined by applying an AC excitation to reference resistances and an ultra-stable aged thermistor. The reference resistor is a hermetically sealed VISHAY. AC excitation and ratiometric comparison using a common processing channel removes measurement errors due to parasitic thermocouples, offset voltages, leakage currents and gain errors.

The SBE38 can operate in polled sampling, where it takes one sample and transmits the data, or in continuous sampling.

Specifications

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

Turner Designs Self-Contained Underwater Fluorescence Apparatus (SCUFA)

The Turner Designs SCUFA is a submersible fluorometer for chlorophyll and dye tracing operations that has been designed to operate in a wide range of concentrations, environmental conditions as well as operational modes (profiling or moored deployments). The instrument includes an integrated temperature probe and software which allow for automatic correction of fluorescence data from temperature effects. The superior ambient light rejection eliminates the effects of sunlight and allows the SCUFA to be used in surface waters without the need for external pumps or light shields.

Each instrument can be customised to meet user requirements. Users can choose one of the following channels: chlorophyll a, cyanobacteria (phycocyanin or phycoerythrin pigments), rhodamine WT, fluorescein and turbidity. Instrument options include turbidity, internal data logging and automatic temperature correction.

Three versions of the SCUFA are available: SCUFA I, II and III. SCUFA I and II are used for chlorophyll a applications, while SCUFA III is used for Rhodamine WT. Models II and III include a turbidity channel that is not present on model I. The SCUFA has been out of production since 2008.

Specifications

The table below presents the specifications for the different channels.

Further details can be found in the manufacturer's brochure.

WETLabs C-Star transmissometer

This instrument is designed to measure beam transmittance by submersion or with an optional flow tube for pumped applications. It can be used in profiles, moorings or as part of an underway system.

Two models are available, a 25 cm pathlength, which can be built in aluminum or co-polymer, and a 10 cm pathlength with a plastic housing. Both have an analog output, but a digital model is also available.

This instrument has been updated to provide a high resolution RS232 data output, while maintaining the same design and characteristics.

Specifications

Further details are available in the manufacturer's specification sheet or user guide.

PD04_08 Sea surface hydrography instrument details

Underway hydrography was recorded by a suite of instruments in the ship's flow through system and a temperature sensor located near the flow through intake, at the hull. The depth of the flow through intake was 3 m. Instrument details are given in the table below.

SeaBird MicroTSG Thermosalinograph SBE 45

The SBE45 MicroTSG is an externally powered instrument designed for shipboard measurement of temperature and conductivity of pumped near-surface water samples. The instrument can also compute salinity and sound velocity internally.

The MicroTSG comprises a platinum-electrode glass conductivity cell and a stable, pressure-protected thermistor temperature sensor. It also contains an RS-232 port for appending the output of a remote temperature sensor, allowing for direct measurement of sea surface temperature.

The instrument can operate in Polled, Autonomous and Serial Line Sync sampling modes:

• Polled sampling: the instrument takes one sample on command
• Autonomous sampling: the instrument samples at preprogrammed intervals and does not enter quiescence (sleep) state between samples
• Serial Line Sync: a pulse on the serial line causes the instrument to wake up, sample and re-enter quiescent state automatically

Specifications

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

Prince Madog Cruise PD04_08 Sea Surface Hydrography Series

Hydrography Processing Notes

• Salinity

  TSG salinity was checked against independent measurements by comparing TSG salinity with concurrent CTD surface salinity, averaged over the top 3 m. It was not possible to obtain a reliable calibration beyond application of the manufacturer's coefficients (which occurred during processing) because of the extremely variable nature of the sampled estuarine water column. Over 50% of the available salinity data (44 of 84 samples) had to be discarded as they were sampled in salinity gradients. The offset between CTD salinity and underway salinity was examined to see if it varied with time, or CTD salinity. Regression analysis did not yield a significant relationship between salinity offset and either time or CTD salinity at 95% confidence. The mean offset = -0.0045 with standard deviation = 0.1693. The large standard deviation indicated the level of variability in the data so it was deemed inappropriate to apply further calibrations to the data. The RMS difference between CTD salinity and underway salinity is 0.1672 and the residual range is between -0.343 to 0.521.

• Sea surface temperature

  Temperature was calibrated by comparing underway hull temperature with concurrent CTD surface temperature, averaged over the top 3 m. It was not possible to obtain a reliable calibration beyond application of the manufacturer's coefficients (which occurred during processing) because of the extremely variable nature of the sampled estuarine water column. 30% of the available temperature data (26 of 83 samples) had to be discarded because they were sampled in temperature gradients. The offset between CTD temperature and underway temperature was examined to see if it varied with time or CTD temperature. No significant relationship was found between offset (CTD temperature - underway temperature) and any other parameter at 95% confidence. The mean offset (CTD temperature - underway temperature) = -0.00295 with standard deviation = 0.06032. The large standard deviation indicated the level of variability in the data so it was deemed inappropriate to apply further calibrations. The RMS difference between CTD temperature and underway temperature = 0.0598, with a residual range between -0.133 to 0.304.

• Beam attenuation

  The data were logged as linear voltages. The cruise air readings were used to correct the reference voltage for instrument drift over time. The corrected reference voltage was then used to calculate the beam transmission value (equation 1 - Meuller et al., 2003). Beam attenuation was calculated from this using equation 2.

  (1)	T = (Vsig - Vd CR) / [((Vair CR) - (Vd CR) / (Vair F) - (Vd F)) * (Vref F - Vd F)]
  (2)	Atten = [(-1/R) * ln (T) ] + 0.364

  Where V_sig = signal recorded by instrument during deployment; V_d ^CR = blank cruise voltage = 0.0569; V_air ^CR = cruise air voltage = 4.7140; V_air ^F = manufacturer's air voltage = 4.847; V_d ^F = manufacturer's blocked path voltage = 0.062; V_ref ^F = manufacturer's pure water reference voltage = 4.897; T = beam transmission; R = optical path length (m) = 0.1.

  The constant 0.364, which is the beam attenuation for particle free water, is added because the C-Star transmissometer is configured to output attenuation due to particulates alone. The addition of this constant converts the record into the attenuation due to water and particles.

  References

  Mueller, J.M et al., 2003: Ocean Optics Protocols for Satellite Ocean Colour Sensor Validation, Revision 4, Volume IV. Inherent Optical Properties: Instruments, Characterizaton, Fields Measurements and Data Analysis Protocols, NASA/TM-2003-21621, Goddard Space Flight Centre, 76pp

• Fluorescence and turbidity

  The data were logged as linear voltages. No calibration data were supplied, so fluorescence and turbidity remain as unprocessed voltages. The channels were examined graphically and any suspect values flagged. Inter-comparison with the beam attenuation channel was carried out.

Prince Madog Cruise PD04_08 Sea Surface Hydrography, Meteorology and Navigation Series

Data acquisition

Surface hydrographic (ship's intake 3 m below surface), meteorology measurements and supplementary navigation data, including ship heading and bathymetric depth were time stamped and logged to a central logging system. The data underwent conversion from raw counts into engineering units and were submitted as daily text files to BODC, at 60 second resolution, for further processing.

BODC underway data processing procedures

All underway sea surface hydrography, meteorology and ship's navigation data were merged into a common QXF file. Navigation was checked for improbable speeds and gaps, visual screening was done for each channel and any additional data calibrations were applied as appropriate.

The QXF file then underwent a further step. This involved using Matlab transfer 378 to split the underway QXF file into three separate QXF files. One contained data for sea surface hydrography, one for meteorological data and the final QXF file held the navigation data.

Each data channel was visually inspected on a graphics workstation and any spikes or periods of dubious data were flagged as suspect. The capabilities of the workstation screening software allows all possible comparative screening checks between channels (e.g. to ensure corrected wind data have not been influenced by changes in ship's heading). The system also has the facility of simultaneously displaying the data and the ship's position on a map to enable data screening to take oceanographic climatology into account.

Project Information

Oceans 2025 Theme 3, Work Package 3.3: Bottom Boundary Layer, Optics and Suspended Sediments Processes

This Work Package (WP) is a combination of Work Package 3.3 and 3.4 as proposed in the original Oceans 2025 proposal. It continues and expands the research undertaken in the Proudman Oceanographic Laboratory Dee Experiment project.

Sediment transport process models underpin scientific ability to predict the entrainment of sediments into the water column and the transport of sediments for forecasting seabed and coastal morphodynamic evolution. The difficulty in achieving accurate process models lies with the complex inter-dependence of sediment processes in the bottom boundary layer. Near the bed, the fundamentals of sediment transport are governed by interactions between the sediment transport triad; the bed, the hydrodynamics and the mobile sediments. These three components interrelate, being mutually interactive and interdependent.

POL aim to use a combination of high-frequency underwater acoustics and laser optical measurements to make co-located simultaneous measurements of the triad. These measurements provide an observational framework capable of assessing and advancing the latest sediment transport models available. These measurements will be made in a range of environments, with the objective of achieving significant advances in understanding and modelling capability in coastal sediment transport. POL will also address the dynamics of suspended sediment behaviour in the context of sediment supply to the coastal zone from estuaries, and of coastal water column optical properties. Ths will allow improvement of the modelling accuracy of coastal suspended sediment transport and enable development of a new description of sediment suspension and water opacity that will improve simulation of coastal primary productivity.

The specific objectives are:

• Assess process-based models over different sediment types, cohesive to non-cohesive
• Investigate intra-wave and turbulence processes over flat and rippled beds to improve process based sediment transport models; parameterisation of the process modelling output for input into large-scale area models
• Advance the description and parameterisation of the impact benthic biota has on sediment transport processes (jointly with the Plymouth Marine Laboratory (PML))
• Acquire new knowledge of the dynamics of sediment flocculation and its impact on suspended particulate material (SPM) in shelf seas and estuaries
• Provide preliminary formulations for aggregation-disaggregation and test these formulations using shelf sea models of the Eastern Irish Sea
• Develop understanding of the processes that affect the sediment fluxes between estuaries and the adjacent shelf sea.
• Derive and apply formulations of the effects of SPM on optical attenuation and absorption and assess their potential impact on primary productivity using existing models

Fieldwork

The study site chosen by POL for this research was the Dee Estuary, Liverpool Bay. POL performed fieldwork in the Hilbre Channel on the eastern side of the Estuary and the Welsh Channel on the western exit of the Estuary, with emphasis placed on two repeat stations, HC and WC. The fieldwork under Work Package 3.3 commenced in April 2007 and has been summarised below:

More detailed information on this Work Package is available at pages 8 - 9 and 9-10 of the official Oceans 2025 Theme 3 document: Oceans 2025 Theme 3

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

Oceans 2025 Theme 3: Shelf and Coastal Processes

Over the next 20 years, UK local marine environments are predicted to experience ever-increasing rates of change - including increased temperature and seawater acidity, changing freshwater run-off, changes in sea level, and a likely increase in flooding events - causing great concern for those charged with their management and protection. The future quality, health and sustainability of UK marine waters require improved appreciation of the complex interactions that occur not only within the coastal and shelf environment, but also between the environment and human actions. This knowledge must primarily be provided by whole-system operational numerical models, able to provide reliable predictions of short and long-term system responses to change.

However, such tools are only viable if scientists understand the underlying processes they are attempting to model and can interpret the resulting data. Many fundamental processes in shelf edge, shelf, coastal and estuarine systems, particularly across key interfaces in the environment, are not fully understood.

Theme 3 addresses the following broad questions:

• How do biological, physical and chemical processes interact within shelf, coastal and estuarine systems, particularly at key environmental interfaces (e.g. coastline, sediment-water interface, thermocline, fronts and the shelf edge)?
• What are the consequences of these interactions on the functioning of the whole coastal system, including its sensitivity and/or resilience to change?
• Ultimately, what changes should be expected to be seen in the UK coastal environment over the next 50 years and beyond and how might these changes be transmitted into the open ocean?

Within Oceans 2025, Theme 3 will develop the necessary understanding of interacting processes to enable the consequences of environmental and anthropogenic change on UK shelf seas, coasts and estuaries to be predicted. Theme 3 will also provide knowledge that can improve the forecasting capability of models being used for the operational management of human activities in the coastal marine environment. Theme 3 is therefore directly relevant to all three of NERC's current strategic priorities; Earth's Life-Support Systems, Climate Change, and Sustainable Economies

The official Oceans 2025 documentation for this Theme is available from the following link: Oceans 2025 Theme 3

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

Proudman Oceanographic Laboratory Dee Experiment

Introduction

Sediment transport process models are a vital tool in allowing scientists to predict sediment transport and forecast seabed and coastal morphodynamic evolution. It is however, difficult to obtain accurate models due to the complex inter-dependence of sediment processes in the bottom boundary layer. This inter-dependence is governed by interactions between the sediment transport triad; the bed, the hydrodynamics and the mobile sediments.

Scientific Objectives

• To use a varying suite of instruments to make co-located measurements of the sediment triad
• To provide a framework to allow assessment and improvement of the latest sediment transport models
• To address dynamics of suspended sediments in terms of supply of material to the coastal zone from estuaries
• Development of a new description of suspended sediment and water opacity to improve simulation of coastal primary productivity

Fieldwork

The study site chosen by POL for this research was the Dee Estuary, Liverpool Bay. POL performed fieldwork in the Hilbre Channel on the eastern side of the Estuary and the Welsh Channel on the western exit of the Estuary, with emphasis placed on two repeat stations, HC and WC. The fieldwork started in February 2005 and has been summarised below:

Funding

The Dee Experiment project was core funded by POL under Programme 2 (Shallow coastal seas) Theme 5 (Coastal and sediment processes) of POL's Science Programme 2001 - 2006. From March 2007 onwards, this core funding was replaced by funding from NERC's Oceans 2025 programme and the Dee Experiment research continued as part of Oceans 2025 Work Package 3.3.

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

No Fixed Station Information held for the Series

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: