Metadata Report for BODC Series Reference Number 1371481


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Sea-Bird SBE 911 CTD  CTD; water temperature sensor; salinity sensor
Sea-Bird SBE 43 Dissolved Oxygen Sensor  dissolved gas sensors
Chelsea Technologies Group Aquatracka fluorometer  fluorometers
Chelsea Technologies Group 2-pi PAR irradiance sensor  radiometers
WETLabs ECO BB(RT)D Scattering Meter  optical backscatter sensors
Paroscientific 410K Pressure Transducer  water temperature sensor; water pressure sensors
Sea-Bird SBE 3plus (SBE 3P) temperature sensor  water temperature sensor
Sea-Bird SBE 4C conductivity sensor  salinity sensor
Chelsea Technologies Group Aquatracka III fluorometer  fluorometers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Jo Hopkins
Originating Organization National Oceanography Centre, Liverpool
Processing Status banked
Project(s) Shelf Sea Biogeochemistry (SSB)
SSB CaNDyFloSS
 

Data Identifiers

Originator's Identifier DY008_CAST02_STNNBR_4
BODC Series Reference 1371481
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2014-03-21 15:56
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars
 

Spatial Co-ordinates

Latitude 51.12100 N ( 51° 7.3' N )
Longitude 6.16623 W ( 6° 10.0' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 6.94 m
Maximum Sensor Depth 92.17 m
Minimum Sensor Height 12.82 m
Maximum Sensor Height 98.06 m
Sea Floor Depth 105.0 m
Sensor Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
ATTNMR01 1 per metre Atten_red Attenuation (red light wavelength) per unit length of the water body by 20 or 25cm path length transmissometer
BB117R02 1 per metre per nanometre per steradian AttenBS_650nm_117deg Attenuation due to backscatter (650 nm wavelength at 117 degree incidence) by the water body [particulate >unknown phase] by in-situ optical backscatter measurement
CNDCST01 1 Siemens per metre CTDCond Electrical conductivity of the water body by CTD
CPHLPS01 1 Milligrams per cubic metre chl-a_water_ISfluor_sampcal Concentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >unknown phase] by in-situ chlorophyll fluorometer and calibration against sample data
DOXYZZ01 1 Micromoles per litre WC_dissO2_IS Concentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ sensor
DWIRPP01 1 Watts per square metre DWIrr_2-piPAR Downwelling 2-pi scalar irradiance as energy (PAR wavelengths) in the water body by 2-pi scalar radiometer
OXYSZZ01 1 Percent O2Sat Saturation of oxygen {O2 CAS 7782-44-7} in the water body [dissolved plus reactive particulate phase]
POTMCV01 1 Degrees Celsius WC_Potemp Potential temperature of the water body by computation using UNESCO 1983 algorithm
PRESPR01 1 Decibars Pres_Z Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level
PSALST01 1 Dimensionless P_sal_CTD Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm
SIGTPR01 1 Kilograms per cubic metre SigTheta Sigma-theta of the water body by CTD and computation from salinity and potential temperature using UNESCO algorithm
TEMPST01 1 Degrees Celsius WC_temp_CTD Temperature of the water body by CTD or STD
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

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

Sea-Bird Dissolved Oxygen Sensor SBE 43 and SBE 43F

The SBE 43 is a dissolved oxygen sensor designed for marine applications. It incorporates a high-performance Clark polarographic membrane with a pump that continuously plumbs water through it, preventing algal growth and the development of anoxic conditions when the sensor is taking measurements.

Two configurations are available: SBE 43 produces a voltage output and can be incorporated with any Sea-Bird CTD that accepts input from a 0-5 volt auxiliary sensor, while the SBE 43F produces a frequency output and can be integrated with an SBE 52-MP (Moored Profiler CTD) or used for OEM applications. The specifications below are common to both.

Specifications

Housing Plastic or titanium
Membrane

0.5 mil- fast response, typical for profile applications

1 mil- slower response, typical for moored applications

Depth rating

600 m (plastic) or 7000 m (titanium)

10500 m titanium housing available on request

Measurement range 120% of surface saturation
Initial accuracy 2% of saturation
Typical stability 0.5% per 1000 h

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

Instrument Description for DY008 CTD

CTD Unit and Auxiliary Sensors

The CTD unit comprised a Sea-Bird Electronics (SBE) 9 plus underwater unit, an SBE 11 plus deck unit, a 24-way SBE 32 carousel and 24 10 L TMF Water Samplers; all of which were mounted on a titanium 24-way CTD frame. Attached to the CTD were two SBE 3P temperature sensors, two SBE 4C conductivity sensors, one Paroscientific Digiquartz pressure sensor, one SBE 43 dissolved oxygen sensor, one Chelsea Technology Group (CTG) 2-π PAR sensor, one WETLabs BBRTD light scattering sensor, one Benthos 916T altimeter one CTG Aquatracka MKIII fluorometer and one CTG Alphatracka MKII transmissometer. The WETLabs BBRTD gave suspect readings during the first three deployments, so it was replaced by a backup instrument between casts three and four. The altimeter cable was also replaced at the same time as it gave erratic readings during casts one to three.

Sensor unit Model Serial number Full specification Calibration dates (YYYY/MM/DD) Comments
CTD underwater unit SBE 9 plus 09P-71442-1142 (Ti) SBE 9 plus - -
CTD deck unit SBE 11 plus 11P-34173-0676 - - -
Carousel SBE 32 - 24 Position Pylon 32-37898-0518 SBE 32 - -
Pressure sensor Paroscientific Digiquartz 124216 Paroscientific Digiquartz 2013-03-12 -
Temperature sensor SBE 3P 3P-5494 (Ti) SBE 03P 2013-10-18 -
Temperature sensor SBE 3P 3P-5785 (Ti) - 2013-02-28 -
Conductivity senor SBE 4C 4C-2164 (Ti) SBE 04C 2013-08-07 -
Conductivity sensor SBE 4C 4C-4140 (Ti) - 2013-02-21 -
Dissolved oxygen sensor SBE 43 43-2055 SBE 43 2013-07-23 -
Altimeter Benthos PSA 916T 59493 Benthos Altimeter - -
Irradiance sensor (DWIRR) CTG 2-π PAR PAR 04 (Ti) CTG 2-π PAR 2013-11-21 Measuring downwelling irradiance
Light scattering sensor WETLabs BBRTD Casts 1-3: 1055Casts 4-14: 182 WETLabs BBRTD 2013-03-132013-09-05 -
Fluorometer Chelsea MKIII Aquatracka 88-2615-124 Chelsea MKII Aquatracka 2012-10-19 -
Transmissometer Chelsea MKII Alphatracka - 25 cm path 07-6075-001 Alphatracka MKII 2012-05-08 -

Sea-Bird Electronics SBE 911 and SBE 917 series CTD profilers

The SBE 911 and SBE 917 series of conductivity-temperature-depth (CTD) units are used to collect hydrographic profiles, including temperature, conductivity and pressure as standard. Each profiler consists of an underwater unit and deck unit or SEARAM. Auxiliary sensors, such as fluorometers, dissolved oxygen sensors and transmissometers, and carousel water samplers are commonly added to the underwater unit.

Underwater unit

The CTD underwater unit (SBE 9 or SBE 9 plus ) comprises a protective cage (usually with a carousel water sampler), including a main pressure housing containing power supplies, acquisition electronics, telemetry circuitry, and a suite of modular sensors. The original SBE 9 incorporated Sea-Bird's standard modular SBE 3 temperature sensor and SBE 4 conductivity sensor, and a Paroscientific Digiquartz pressure sensor. The conductivity cell was connected to a pump-fed plastic tubing circuit that could include auxiliary sensors. Each SBE 9 unit was custom built to individual specification. The SBE 9 was replaced in 1997 by an off-the-shelf version, termed the SBE 9 plus , that incorporated the SBE 3 plus (or SBE 3P) temperature sensor, SBE 4C conductivity sensor and a Paroscientific Digiquartz pressure sensor. Sensors could be connected to a pump-fed plastic tubing circuit or stand-alone.

Temperature, conductivity and pressure sensors

The conductivity, temperature, and pressure sensors supplied with Sea-Bird CTD systems have outputs in the form of variable frequencies, which are measured using high-speed parallel counters. The resulting count totals are converted to numeric representations of the original frequencies, which bear a direct relationship to temperature, conductivity or pressure. Sampling frequencies for these sensors are typically set at 24 Hz.

The temperature sensing element is a glass-coated thermistor bead, pressure-protected inside a stainless steel tube, while the conductivity sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Thermistor resistance or conductivity cell resistance, respectively, is the controlling element in an optimized Wien Bridge oscillator circuit, which produces a frequency output that can be converted to a temperature or conductivity reading. These sensors are available with depth ratings of 6800 m (aluminium housing) or 10500 m (titanium housing). The Paroscientific Digiquartz pressure sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.

Additional sensors

Optional sensors for dissolved oxygen, pH, light transmission, fluorescence and others do not require the very high levels of resolution needed in the primary CTD channels, nor do these sensors generally offer variable frequency outputs. Accordingly, signals from the auxiliary sensors are acquired using a conventional voltage-input multiplexed A/D converter (optional). Some Sea-Bird CTDs use a strain gauge pressure sensor (Senso-Metrics) in which case their pressure output data is in the same form as that from the auxiliary sensors as described above.

Deck unit or SEARAM

Each underwater unit is connected to a power supply and data logging system: the SBE 11 (or SBE 11 plus ) deck unit allows real-time interfacing between the deck and the underwater unit via a conductive wire, while the submersible SBE 17 (or SBE 17 plus ) SEARAM plugs directly into the underwater unit and data are downloaded on recovery of the CTD. The combination of SBE 9 and SBE 17 or SBE 11 are termed SBE 917 or SBE 911, respectively, while the combinations of SBE 9 plus and SBE 17 plus or SBE 11 plus are termed SBE 917 plus or SBE 911 plus .

Specifications

Specifications for the SBE 9 plus underwater unit are listed below:

Parameter Range Initial accuracy Resolution at 24 Hz Response time
Temperature -5 to 35°C 0.001°C 0.0002°C 0.065 sec
Conductivity 0 to 7 S m -1 0.0003 S m -1 0.00004 S m -1 0.065 sec (pumped)
Pressure 0 to full scale (1400, 2000, 4200, 6800 or 10500 m) 0.015% of full scale 0.001% of full scale 0.015 sec

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

Aquatracka fluorometer

The Chelsea Instruments Aquatracka is a logarithmic response fluorometer. It uses a pulsed (5.5 Hz) xenon light source discharging between 320 and 800 nm through a blue filter with a peak transmission of 420 nm and a bandwidth at half maximum of 100 nm. A red filter with sharp cut off, 10% transmission at 664 nm and 678 nm, is used to pass chlorophyll-a fluorescence to the sample photodiode.

The instrument may be deployed either in a through-flow tank, on a CTD frame or moored with a data logging package.

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

Chelsea Technologies Group Aquatracka MKIII fluorometer

The Chelsea Technologies Group Aquatracka MKIII is a logarithmic response fluorometer. Filters are available to enable the instrument to measure chlorophyll, rhodamine, fluorescein and turbidity.

It uses a pulsed (5.5 Hz) xenon light source discharging along two signal paths to eliminate variations in the flashlamp intensity. The reference path measures the intensity of the light source whilst the signal path measures the intensity of the light emitted from the specimen under test. The reference signal and the emitted light signals are then applied to a ratiometric circuit. In this circuit, the ratio of returned signal to reference signal is computed and scaled logarithmically to achieve a wide dynamic range. The logarithmic conversion accuracy is maintained at better than one percent of the reading over the full output range of the instrument.

Two variants of the instrument are available, both manufactured in titanium, capable of operating in depths from shallow water down to 2000 m and 6000 m respectively. The optical characteristics of the instrument in its different detection modes are visible below:

Excitation Chlorophyll a Rhodamine Fluorescein Turbidity
Wavelength (nm) 430 500 485 440 *
Bandwidth (nm) 105 70 22 80 *
Emission Chlorophyll a Rhodamine Fluorescein Turbidity
Wavelength (nm) 685 590 530 440 *
Bandwidth (nm) 30 45 30 80 *

* The wavelengths for the turbidity filters are customer selectable but must be in the range 400 to 700 nm. The same wavelength is used in the excitation path and the emission path.

The instrument measures chlorophyll a, rhodamine and fluorescein with a concentration range of 0.01 µg l -1 to 100 µg l -1 . The concentration range for turbidity is 0.01 to 100 FTU (other wavelengths are available on request).

The instrument accuracy is ± 0.02 µg l -1 (or ± 3% of the reading, whichever is greater) for chlorophyll a, rhodamine and fluorescein. The accuracy for turbidity, over a 0 - 10 FTU range, is ± 0.02 FTU (or ± 3% of the reading, whichever is greater).

Further details are available from the Aquatracka MKIII specification sheet .

Chelsea Technologies Photosynthetically Active Radiation (PAR) Irradiance Sensor

This sensor was originally designed to assist the study of marine photosynthesis. With the use of logarithmic amplication, the sensor covers a range of 6 orders of magnitude, which avoids setting up the sensor range for the expected signal level for different ambient conditions.

The sensor consists of a hollow PTFE 2-pi collector supported by a clear acetal dome diverting light to a filter and photodiode from which a cosine response is obtained. The sensor can be used in moorings, profiling or deployed in towed vehicles and can measure both upwelling and downwelling light.

Specifications

Operation depth 1000 m
Range 2000 to 0.002 µE m -2 s -1
Angular Detection Range ± 130° from normal incidence
Relative Spectral Sensitivity

flat to ± 3% from 450 to 700 nm

down 8% of 400 nm and 36% at 350 nm

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

WETLabs Single-angle Backscattering Meter ECO BB

An optical scattering sensor that measures scattering at 117°. This angle was determined as a minimum convergence point for variations in the volume scattering function induced by suspended materials and water. The measured signal is less determined by the type and size of the materials in the water and is more directly correlated to their concentration.

Several versions are available, with minor differences in their specifications:

Specifications

Wavelength 471, 532, 660 nm
Sensitivity (m -1 sr -1 )

1.2 x 10 -5 at 470 nm

7.7 x 10 -6 at 532 nm

3.8 x 10 -6 at 660 nm

Typical range ~0.0024 to 5 m -1
Linearity 99% R 2
Sample rate up to 8Hz
Temperature range 0 to 30°C
Depth rating

600 m (standard)

6000 m (deep)

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

Paroscientific Absolute Pressure Transducers Series 3000 and 4000

Paroscientific Series 3000 and 4000 pressure transducers use a Digiquartz pressure sensor to provide high accuracy and precision data. The sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.

The 3000 series of transducers includes one model, the 31K-101, whereas the 4000 series includes several models, listed in the table below. All transducers exhibit repeatability of better than ±0.01% full pressure scale, hysteresis of better than ±0.02% full scale and acceleration sensitivity of ±0.008% full scale /g (three axis average). Pressure resolution is better than 0.0001% and accuracy is typically 0.01% over a broad range of temperatures.

Differences between the models lie in their pressure and operating temperature ranges, as detailed below:

Model Max. pressure (psia) Max. pressure (MPa) Temperature range (°C)
31K-101 1000 6.9 -54 to 107
42K-101 2000 13.8 0 to 125
43K-101 3000 20.7 0 to 125
46K-101 6000 41.4 0 to 125
410K-101 10000 68.9 0 to 125
415K-101 15000 103 0 to 50
420K-101 20000 138 0 to 50
430K-101 30000 207 0 to 50
440K-101 40000 276 0 to 50

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

Originator's processing document for DY008 CTD data

Sampling strategy

A total of 14 CTD casts were performed during DY008 which sailed from Southampton on 18 March 2014 and docked in Southampton on 13 April 2014, and was tasked with investigating the benthic work package (Work Package II) of the Shelf Seas Biogeochemistry project in the Celtic Sea.

Data Processing

For each CTD cast the following raw data files were generated:

where XYZ is the cast number of the CTD data series.

The following processing was performed by the Originator using the SBE Data Processing software (Seasave Version 7.23.2):

  1. DatCnv was used to read in the raw CTD data file (.hex) which contained the data in engineering units and apply calibrations as appropriate through the instrument configurations (.con) file.
  2. Bottle Summary was run to create a .btl file containing the average, standard deviation, min and max values recorded by the CTD instrument suite at bottle firings.
  3. Wild Edit was run to remove spikes in the pressure channel.
  4. Filter was run on the pressure channel to smooth out the high frequency data
  5. After examining the data recorded during four casts (one, two, seven and 14) the originator used AlignCTD to advance the oxygen data by two seconds. AlignCTD was also used to move the conductivity data backwards by one scan (0.0417 seconds), as after testing several values this adjustment resulted in the fewest number of spikes in the salinity channel.
  6. CellTM was run using alpha = 0.03 and 1/beta = 7, to correct for conductivity errors induced by the transfer of heat from the conductivity cell to the seawater.
  7. Derive was run to create the variables Salinity, Salinity 2, Oxygen SBE 43 and Oxygen Tau correction. The output file was then saved as DY008_XYZ_derive.cnv.
  8. BinAverage and Strip were run to average the data to 2Hz bins (0.5 seconds) and to remove the salinity and oxygen channels which were created when Derive was run. The output file was then saved as DY008_XYZ_derive_2Hz.cnv.

The originator then proceeded to process the data further in Matlab.

  1. The data from the 2HZ and 24HZ processed CTD data files were extracted and combined with metadata from the Event log to create .mat files for each series at both 2HZ and 24 HZ resolutions.
  2. Inspection of the raw turbidity data revealed that there was a bug in the Seasave DatCnv conversion module which resulted in it incorrectly converting the raw turbidity voltage into m -1 sr -1 . Therefore, the originator re-derived turbidity manually using the following equation (SF = scale factor, DC = dark counts):

    CTDturb = CTDturb_raw x SF - (SF x DC)

  3. The originator manually inspected the 2Hz data files to identify the surface soak and then cropped the 2Hz and 24Hz data files to remove the surface soak from the data.
  4. The salinity, conductivity, temperature, oxygen, attenuation, turbidity and fluorescence channels in the 24Hz data files were all de-spiked using an automated routine, with the originator converting the spikes to NaN (not a number) values.
  5. Further manual de-spiking was carried out to identify larger periods of bad data.
  6. The 24Hz data were averaged into one decibar downcast only bins and liner interpolation was used to fill gaps in the profile.
  7. All channels except PAR were smoothed further using a 10 m running median.
  8. The salinity data were then calibrated using salinity samples collected by the CTD water bottles and analysed on a Guildline Autosal salinometer. The chlorophyll fluresence data were calibrated against CTD chlorophyll samples.
  9. It was this calibrated version of the data which were then ingested by BODC, although all other versions have been archived and are available on request.

Field Calibrations

Salinity

29 usable salinity samples were collected from CTD water bottle samples during DY008 and analysed on a Guildline Autosal salinometer (SN 71126). Using all samples the mean and standard deviation of residuals from the primary and secondary sensors were calculated as 0.0018586 ± 0.0020348 and 0.0043345 ± 0.0021767 respectively. After removing the outliers where the difference between Autosal and CTD values was greater than two standard deviations, the mean for the primary and secondary sensors was reduced to 0.0013423 ± 0.001392 and 0.0039815 ± 0.0017942 respectively. These mean values were then used to correct the CTD salinity channels.

Chlorophyll

A total of 24 samples were collected from CTD water bottle samples to calibrate the chlorophyll flurometer. The originator used a linear regression to calibrate the chlorophyll fluorometer against the 39 chlorophyll samples, with the following calibration equation being used to calibrate the fluorometer:

CHL = 3.0178 x CTDfluor - 0.13846

R 2 = 0.87469

More information on the processing carried out and calibrations applied by the data originator the can be found in the data originator's CTD Processing Report .

Processing by BODC of RRS Discovery DY008 CTD data

Several versions of the CTD data recorded during DY008 arrived at BODC in the form of ASCII and Matlab (.MAT) files. In addition to the raw CTD data, BODC were provided with the 24 Hz and 2 Hz versions created at the end of the originator's Seasave processing and at each subsequent stage of Matlab processing. The fully calibrated CTD data binned to 1db downcast bins were then reformatted to BODC's internal NetCDF format. The following table shows the mapping of the originator's variables to the appropriate BODC parameter codes:

Originator's Variable Units Description BODC Parameter Code Units Comment
pres db Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level PRESPR01 Decibars -
time elapsed [seconds] - - - This variable was not transferred
temp1 ITS-90, deg C Temperature of the water body TEMPPR01 °C -
temp2 ITS-90, deg C - - - This parameter was transferred then dropped following screening as there was no difference between the quality of the data from the first and second temperature sensors
cond1 S m -1 Electrical conductivity of the water body by CTD CNDCST01 S m -1 -
cond2 S m -1 - - - This parameter was transferred then dropped following screening as there was no difference between the quality of the data from the first and second temperature sensors
sal1 PSU, PSS-78 Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm PSALST01 Dimensionless Derived from temp1 and cond1
sal2 PSU, PSS-78 - - - This parameter was transferred then dropped following screening as there was no difference between the quality of the data from the first and second temperature sensors
oxy_umoll µ mol l -1 Concentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ sensor DOXYZZ01 µ mol l -1 -
fluor µ g l -1 Concentration of chlorophyll-a {chl-a CAS479-61-8} per unit volume of the water body [particulate >unknown phase] by in-situ chlorophyll fluorometer and calibration against sample data CPHLPS01 mg m -3 µ g l -1 = mg m -3
par W m -2 Downwelling 2-pi scalar irradiance as energy (PAR wavelengths) in the water body by 2-pi scalar radiometer DWIRPP01 W m -2 -
att m -1 Attenuance (red light wavelength) per unit length of the water body by 20 or 25cm path length transmissometer ATTNMR01 m -1 -
sigma_theta - - - - This variable was not transferred. BODC independently derive density during transfer
turb m -1 sr -1 Attenuance due to backscatter (660 nm wavelength at 117 degree incidence) by the water body [particulate >unknown phase] by in-situ optical backscatter measurement BB117R01 m -1 nm -1 sr -1 Casts 04 to 14 only. m -1 sr -1 = m -1 nm -1 sr -1
turb m -1 sr -1 Attenuance due to backscatter (650 nm wavelength at 117 degree incidence) by the water body [particulate >unknown phase] by in-situ optical backscatter measurement BB117R02 m -1 nm -1 sr -1 Casts 01 to 03 only. m -1 sr -1 = m -1 nm -1 sr -1

The following additional parameters were derived when the data were converted into QXF format:

Originator's Variable Units Description BODC Parameter Code Units Comment
- - Potential temperature of the water body by computation using UNESCO 1983 algorithm POTMCV01 °C Derived from TEMPPR01, PSALST01 and PRESPR01
- - Sigma-theta of the water body by CTD and computation from salinity and potential temperature using UNESCO algorithm SIGTPR01 kg m -3 Derived from POTMCV01, PSALST01 and PRESPR01
- - Saturation of oxygen {O2} in the water body [dissolved plus reactive particulate phase] OXYSZZ01 % Derived from TEMPST01, PSALST01 and DOXYZZ01

The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, and missing data by setting the data to an appropriate value and applying the quality control flag.


Project Information

Shelf Sea Biogeochemistry (SSB) Programme

Shelf Sea Biogeochemistry (SSB) is a £10.5 million, six-year (2011-2017) research programme, jointly funded by the Natural Environment Research Council (NERC) and the Department for Environment, Food and Rural Affairs (DEFRA). The aim of the research is to reduce the uncertainty in our understanding of nutrient and carbon cycling within the shelf seas, and of their role in global biogeochemical cycles. SSB will also provide effective policy advice and make a significant contribution to the Living with Environmental Change programme.

Background

The Shelf Sea Biogeochemistry research programme directly relates to the delivery of the NERC Earth system science theme and aims to provide evidence that supports a number of marine policy areas and statutory requirements, such as the Marine Strategy Framework Directive and Marine and Climate Acts.

The shelf seas are highly productive compared to the open ocean, a productivity that underpins more than 90 per cent of global fisheries. Their importance to society extends beyond food production to include issues of biodiversity, carbon cycling and storage, waste disposal, nutrient cycling, recreation and renewable energy resources.

The shelf seas have been estimated to be the most valuable biome on Earth, but they are under considerable stress, as a result of anthropogenic nutrient loading, overfishing, habitat disturbance, climate change and other impacts.

However, even within the relatively well-studied European shelf seas, fundamental biogeochemical processes are poorly understood. For example: the role of shelf seas in carbon storage; in the global cycles of key nutrients (nitrogen, phosphorus, silicon and iron); and in determining primary and secondary production, and thereby underpinning the future delivery of many other ecosystem services.

Improved knowledge of such factors is not only required by marine policymakers; it also has the potential to increase the quality and cost-effectiveness of management decisions at the local, national and international levels under conditions of climate change.

The Shelf Sea Biogeochemistry research programme will take a holistic approach to the cycling of nutrients and carbon and the controls on primary and secondary production in UK and European shelf seas, to increase understanding of these processes and their role in wider biogeochemical cycles. It will thereby significantly improve predictive marine biogeochemical and ecosystem models over a range of scales.

The scope of the programme includes exchanges with the open ocean (transport on and off the shelf to a depth of around 500m), together with cycling, storage and release processes on the shelf slope, and air-sea exchange of greenhouse gases (carbon dioxide and nitrous oxide).

Further details are available on the SSB website.

Participants

15 different organisations are directly involved in research for SSB. These institutions are

In addition, there are third party institutions carrying out sampling work for SSB, but who are not involved in the programme itself. These are:

Research details

Overall, five Work Packages have been funded by the SSB programme. These are described in brief below:

Fieldwork and data collection

The campaign consists of the core cruises in the table below, to the marine shelf (and shelf-edge) of the Celtic Sea on board the NERC research vessels RRS Discovery and RRS James Cook. These cruises will focus on the physics and biogeochemistry of the benthic and pelagic zones of the water column, primarily around four main sampling sites in this area.

Cruise identifier Research ship Cruise dates Work packages
DY008 RRS Discovery March 2014 WP 2 and WP 3
JC105 RRS James Cook June 2014 WP 1, WP 2 and WP 3
DY026 RRS Discovery August 2014 WP1, WP 2 and WP 3
DY018 RRS Discovery November - December 2014 WP 1 and WP 3
DY021 (also known as DY008b) RRS Discovery March 2015 WP 2 and WP 3
DY029 RRS Discovery April 2015 WP 1 and WP 3
DY030 RRS Discovery May 2015 WP 2 and WP 3
DY033 RRS Discovery July 2015 WP 1 and WP 3
DY034 RRS Discovery August 2015 WP 2 and WP 3

Core cruises will be supplemented by partner cruises led by Cefas, MI, MSS, Bangor University and AFBI, spanning the shelf seas and shelf-edges around United Kingdom and Republic of Ireland.

Activities will include coring, Conductivity Temperature and Depth (CTD) deployments, Acoustic Doppler Current Profilers (ADCP) surveys, moorings and wire-walker deployments, benthic lander observatories, autonomous gliders and submersible surveys, Marine Snow Catcher particulate matter analysis, plankton net hauls, in-situ sediment flume investigations and laboratory incubations with core and sea water samples.


Shelf Sea Biogeochemistry (SSB) Programme Work Package 1: CaNDyFloSS

Carbon and Nutrient Dynamics and Fluxes over Shelf Systems (CaNDyFloSS) is a £2.76 million component of the Natural Environment Research Council (NERC) Shelf Sea Biogeochemistry (SSB) research programme, running from 2013 to 2017. It is jointly funded by NERC and the Department for Environment, Food and Rural Affairs (DEFRA). The aim of the research is to perform a comprehensive study of the cycling of nutrients and carbon throughout the water column over the whole north-west European shelf. This will allow the fluxes of nutrients and carbon between the shelf and the deep ocean and atmosphere to be quantified, establishing the role of the north-west European continental shelf in the global carbon cycle.

Background

Shelf seas are the primary regions of human marine resource exploitation, including both renewable and fossil fuel energy sources, recreation, trade and food production. They provide 90% of global fish catches which form an important source of food to much of the global population. They also play an important role in the ecosystem services provided by the oceans as a whole, in particular in storing carbon away from the atmosphere.

Physical and biochemical processes in shelf seas influence the removal of CO2 from the atmosphere and the subsequent storage of carbon in the deep ocean. Biological growth draws carbon out of the water, which is then replaced by carbon in CO2 from the atmosphere. In the shelf seas this growth is supported by terrestrial and open ocean sources of nutrients, implying intimate roles for both the terrestrial biosphere and the open ocean environment in regulating shelf sea climate services. The oceans can also be a major source or sink for other greenhouse gases, including nitrous oxide (N2O), with the shallow shelf sea thought to play a key role.

The spatial extent of the submerged continental shelves varies greatly. The NW European shelf sea is one of the largest and hence is likely to play a significant role in marine biogeochemical cycling, alongside providing a useful model for other systems. However, even in this relatively well studied region, there is a lack of detailed understanding of the principal controls on the cycling of carbon and the major nutrient elements, nitrogen, phosphorus and silicon. Consequently it is also difficult to predict how the cycling of these elements and hence the carbon removal they support may be altered by ongoing and potential future global change. This work package aims to address these uncertainties through a comprehensive study of the cycling of the major nutrients and carbon throughout the water column over the NW European shelf sea system.

Further details are available on the SSB website.

Participants

9 different organisations are directly involved in research for SSB Work Package 1. These institutions are

In addition, there are third party institutions carrying out sampling work for SSB Work Package 1, but who are not involved in the programme itself. These are:

Objectives

Two overarching objectives are defined for this Work Package.

Fieldwork and data collection

Data for Objective 1 will be provided using pCO2 systems aboard third party vessels and ferry boxes, along with measurements made through the FASTNEt programme and through the Work Package 1 process cruises detailed below. The third party cruises will be undertaken by Cefas, MI, MSS, University of Bangor and AFBI, spanning the shelf seas and shelf-edges around the United Kingdom and the Republic of Ireland.

The Work Package 1 process cruises will provide data for Objective 1 and Objective 2 and are listed in the table below. The study area is the marine shelf (and shelf-edge) of the Celtic Sea. Work will be carried out on board the NERC research vessels RRS Discovery and RRS James Cook. These cruises will focus on the physics and biogeochemistry of the benthic and pelagic zones of the water column, primarily around four main sampling sites in this area.

Cruise identifier Research ship Cruise dates Work packages
JC105 RRS James Cook June 2014 WP 1, WP 2 and WP 3
DY026 RRS Discovery August 2014 WP1, WP 2 and WP 3
DY018 RRS Discovery November - December 2014 WP 1 and WP 3
DY029 RRS Discovery April 2015 WP 1 and WP 3
DY033 RRS Discovery July 2015 WP 1 and WP 3

Activities will include Conductivity Temperature and Depth (CTD) deployments, Acoustic Doppler Current Profilers (ADCP) surveys, moorings and wire-walker deployments, autonomous gliders and submersible surveys, Marine Snow Catcher particulate matter analysis, plankton net hauls and laboratory incubations with sea water samples.


Data Activity or Cruise Information

Cruise

Cruise Name DY008
Departure Date 2014-03-18
Arrival Date 2014-04-13
Principal Scientist(s)Henry Ruhl (National Oceanography Centre, Southampton)
Ship RRS Discovery

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameShelf Seas Biogeochemistry Fixed Station East of Celtic Deep
CategoryOffshore area
Latitude51° 7.47' N
Longitude6° 9.52' W
Water depth below MSL103.0 m

Shelf Seas Biogeochemistry Fixed Station East of Celtic Deep

This station is one of four mooring sites located on the continental shelf of the Celtic Sea and maintained during the Shelf Seas Biogeochemistry project. The station has a mean water depth 103 m at the following co-ordinates:

Box Corner Latitude Longitude
North-west corner 51.1281° -6.1662°
South-east corner 51.1210° -6.1510°

The position of this station relative to the other Shelf Seas Biogeochemistry sites can be seen from the figure below.

BODC image

Sampling History

DY008 JC105 DY026 DY018
CTD casts 2 1 2 -
STD casts - 1 - -

Mooring deployments

Latitude Longitude Water depth (m) Moored instrument Deployment date Recovery date Deployment cruise Recovery cruise Comments
51.1237° -6.163° 103 Cefas mini-lander 21-03-2014 14:05 UTC 22-10-2014 10:35 UTC DY008 RV Cefas Endeavour 22/14 Recovery was abandoned during JC105, however was successfully recovered four months later by the RV Cefas Endeavour
51.1281° -6.1557° 101 Cefas mini-lander 18-06-2014 13:52 UTC - JC105 - Mini-lander was lost at sea

Other Series linked to this Fixed Station for this cruise - 1336606 1371468

Other Cruises linked to this Fixed Station (with the number of series) - DY026B (1) JC105 (2)


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

SeaDataNet Quality Control Flags

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

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain