Metadata Report for BODC Series Reference Number 1736021
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
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Parameters |
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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 SBE 19 and SBE 19plus SEACAT Profiler CTDs
The SBE 19 SEACAT Profiler is a self-contained, battery powered, pumped CTD system designed to measure conductivity, temperature, and pressure in marine or fresh water environments to depths of 10,500 meters. It was replaced by the SBE 19plus model in 2001. An updated version of this instrument is the SBE 19plus V2, which incorporates an electronics upgrade and additional features, with six differentially amplified A/D input channels, one RS-232 data input channel, and 64 MB FLASH memory.
The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by titanium housing for depths up to 7000 m. It is typically used for CTD profiling although a conversion kit is available for mooring deployments. The CTD can also be attached to an SBE 36 CTD Deck Unit and Power/Data Interface Module (PDIM) for real-time operation on single-core armored cable up to 10,000 m.
Specifications
| Parameter | SBE 19 | SBE 19plus |
|---|---|---|
| Temperature | Range: -5 to +35 °C Accuracy: 0.01 °C Resolution: 0.001 °C Calibration: +1 to +32 °C* | Range: -5 to +35 °C Accuracy: 0.005 °C Resolution: 0.0001 °C Calibration: +1 to +32 °C* |
| Conductivity | Range: 0 to 7 S m-1 (0 to 70 mmho cm-1) Accuracy: 0.001 S m-1 Resolution: 0.0001 S m-1 Calibration: 0 to 7 S m-1. Physical calibration over the range 1.4 - 6 S m-1* | Range: 0 to 9 Sm-1 Accuracy: 0.0005 Resolution: 0.00005 (most oceanic waters, resolves 0.4 ppm in salinity); 0.00007 (high salinity waters, resolves 0.4 ppm in salinity); 0.00001 (fresh waters, resolves 0.1 ppm in salinity) Calibration: 0 to 9 S m-1. Physical calibration over the range 1.4 - 6 S m-1* |
| Strain gauge pressure sensor | Range: 0 to100, 150, 300, 500, 1000, 1500, 3000, 5000, 10000 or 15000 psia Accuracy: 0.25% of full scale range (100 - 1500 psia); 0.15% of full scale range (3000 - 15000 psia) Resolution: 0.015% of full scale Calibration: 0 to full scale in 20% steps | Range: 0 to 20, 100, 350, 1000, 2000, 3500 or 7000 m Accuracy: 0.1% of full scale range Resolution: 0.002% of full scale range Calibration: ambient pressure to full scale range in 5 steps |
*Measurements outside this range may be at slightly reduced accuracy due to extrapolation errors.
Options and accessories
Additional sensors can be attached to the CTD, including:
- high accuracy Paroscientific Digiquartz pressure sensor (depth range 0 to 20, 60, 130, 200, 270, 680, 1400, 2000, 4200, 7000 or 10500 m; accuracy 0.02% of full scale; resolution 0.0025% of full scale)
- Dissolved Oxygen (SBE 43 DO Sensor)
- pH* (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor)
- fluorescence
- radiance (PAR)
- light transmission
- optical backscatter (turbidity)
The standard SBE 5M pump may be replaced by an SBE 5P (plastic housing) or 5T (titanium housing) pump for use with dissolved oxygen and/or other pumped sensors. Further details can be found in the manufacturer's SBE 19plus V2 instrument specification or theSBE 19 andSBE 19 plus user guides.
BODC Processing
Data Processing
Data collected from the SeaBird 19plus CTD were submitted to BODC in ASCII format representing data collected from a total of 15 stations.
Reformatting
The CTD files were reformatted to an internal format using BODC established procedures. The variables provided in the originators files which were reformatted can be found in the table below.
The parameters which were not reformatted include scan, time, density, sigma theta, depth and flag as these are metadata and hence not measured environmental data. However, these variables are available upon request.
The table below illustrates how the variables reformatted within the ASCII files were mapped to the appropriate BODC parameter codes
| Originators Variable Name | Units | Description | BODC Parameter Code | Units |
|---|---|---|---|---|
| Tv290C | °C | Temperature (ITS-90) of the water body by CTD or STD | TEMPS901 | degC |
| C0mS/cm | mS/cm | Electrical conductivity of the water body by CTD | CNDCST01 | S/m |
| PrdM | dbar | Pressure (measured variable) exerted by the water body by semi-fixed in-situ pressure sensor and corrected to read zero at sea level. | PRESPR01 | dbar |
| Sal00 | PSU | Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm | PSALST01 | Dimensionless |
Derived parameters such as sigma theta and potential temperature were derived during the reformatting process. The conductivity parameter required a unit conversion from mS/cm to the BODC unit of S/m.
Screening
The reformatted data were visualised using the in house software EDSERPLO which checked for any suspect/improbable data. In total 77 M flags have been applied to this data. An M flag is defined as an improbable value and is a BODC quality control flag.
Originators Data Processing
Sampling Strategy
A total of 15 CTD casts were obtained during the RV Prince Madog cruise PD17_12 which took place from the 14 to 24 June 2012 off the coast of Scotland and Irish Sea. The cruise departed from Menai Bridge, Anglesey with CTD profiles beginning the 15 June. The cruise was carried out as part of a NERC funded project "Measurement of the abundance and optical significance of sub-micron particles in the ocean" which finished in 2014. The aim of this project was to test new submersible holographic cameras, with the CTD deployed to determine the physical structure of the water column to aid in the interpretation of the holograms. The CTD deployed was a SeaBird 19plus.
Data Processing
The data processing carried out by the originator followed the standard SeaBird processing procedures comprising the Filter, Align, Cell Thermal Mass, Derive and Bin Average modules, using the manufacturer-recommended constants. The data have been bin-averaged into 1 m bins.
Project Information
NERC Discovery Science- Measurement of the abundance and optical significance of sub-micron sized particles in the ocean
Introduction
The NERC funded project, measurement of the abundance and optical significance of sub-micron sized particles in the ocean, was completed from 2011 to 2014 off the West Coast of Scotland and Irish Sea. This project falls under the NERC standard grants (FEC) NE/H020853/1, NE/H021493/1 and NE/H022090/1.
The main organisations and principal investigators associated with this project include
Scientific Objectives
The objective of this research study was to gain further insight into the estimation of primary production and the role the oceans play in absorbing carbon dioxide from the atmosphere. Understanding the role particles play in the scattering of light, which is responsible for the image observed by satellites, and how large these particles are is an important attribute. Particles in the ocean follow a 'Junge' distribution, in which the number of particles increases rapidly as the size of the particles decrease. Most of the light scattering is performed by particles smaller than 1 micron in diameter hence particles observed in satellite imagery are mostly very small with slow settling speeds and long residence times. The aim of this project was to directly observe, in the sea, the quantity of such small particles as predicted by the Junge distribution.
The main objective of the cruises were to test new submersible holographic cameras, with a Sea-Bird 19plus CTD deployed, to determine the physical structure of the water column to aid in interpreting the holograms. This holographic technique reconstructs very small particles which cannot be measured in any other way. Using different magnifications and commercially available in situ particle sizing instruments, a package of instruments can be made which measure the undisturbed particle size distributions from 0.2 micron to 1 mm.
The insight this provides will be used to construct new theoretical models of particle size distribution and improved measurements of absorption and scattering by particles.
Due to the camera also measuring the shape of the particles, differences between observed and calculated optical properties can be compared, to particle shape, for the first time. The completed data set will be complied to determine what size particles and under what conditions, are primarily responsible for the signals seen in visible band satellite images of the oceans.
Field Work
Field work was carried out at one coastal site over a seasonal cycle, through a variety of water types before and after the spring bloom.
For the NERC funded project NE/H021493/1 the data listed below were obtained over four different periods on board the RV Prince Madog in the Irish Sea and off the coast of Scotland. The cruises took place on 6 to 7 March 2011, 17 and 23 August 2011 and 15 to 22 June 2012.
The NERC funded project NE/H020853/1 obtained CTD data (conductivity, temperature, sigma-theta and salinity). The cruise took place on-board the RV Prince Madog cruise PD17_12 from the 14 to 24 June 2012. The cruise departed from Menai Bridge, Anglesey to complete sampling off the West coast of Scotland and Irish Sea.
NERC funded project NE/H022090/1 took place in 2011 and 2012 acquiring the following data.
Data Availability
The NERC funded data under NE/H022090/1 (see above) is currently restricted to Professor David Bowers from 12 January 2015 to 13 January 2017. Following this date it will be available to the public. The remaining data has no restrictions applied.
Data Activity or Cruise Information
Cruise
| Cruise Name | PD17/12 |
| Departure Date | 2012-06-14 |
| Arrival Date | 2012-06-24 |
| Principal Scientist(s) | David G Bowers (Bangor University School of Ocean Sciences) |
| Ship | RV Prince Madog |
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:
| 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 |
| B | nominal value |
| Q | value below limit of quantification |
