Metadata Report for BODC Series Reference Number 1761792
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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Problem Reports
No Problem Report Found in the Database
CTD data collected from the GEOTRACES Angeles Alvarino MedSeA (GA04S) cruise in the Mediterranean Sea: Quality control report
Salinity
Low values in salinity were observed at the surface on several casts which did not coincide with the remaining profile or bottle data (when available). These values have been flagged as suspect by BODC.
Data Access Policy
Public domain 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.
The recommended acknowledgment is
"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."
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.
CTD data collected from the GEOTRACES Angeles Alvarino MedSeA (GA04S) cruise in the Mediterranean Sea: Instrument Description
CTD unit and auxiliary sensors
The CTD configuration comprised of a Sea-Bird 9plus underwater unit, with accompanying Sea-Bird 11plus deck unit. The CTD frame was fitted with two Sea-Bird 3 Premium temperature sensors, two Sea-Bird 4 conductivity sensors and a digiquartz temperature compensated pressure sensor.
Additional sensors fitted to the CTD frame include a Sea-Bird 43 dissolved oxygen sensor, Biospherical PAR sensor, WETLabs fluorometer and turbidity sensor.
The table below lists more detailed information about the various sensors.
| Sensor Unit | Model | Serial Number | Full Specification | Last calibration date (YYYY-MM-DD) | Comments |
|---|---|---|---|---|---|
| CTD underwater unit | SBE 9plus | - | SBE 9plus | - | - |
| Temperature sensor | SBE 3P | 5604 | SBE 03P | 2012-03-22 | Primary sensor |
| Temperature sensor | SBE 3P | 5573 | SBE 03P | 2013-03-16 | Secondary sensor |
| Conductivity sensor | SBE 4 | 4124 | SBE 04C | 2012-03-23 | Primary sensor |
| Conductivity sensor | SBE 4 | 4125 | SBE 04C | 2012-03-23 | Secondary sensor |
| Pressure sensor | SBE 9plus digiquartz | 1090 | - | 2012-03-19 | - |
| Dissolved Oxygen | Sea-Bird 43 | 2285 | SBE 43 | 2012-03-16 | - |
| PAR/Irradiance | Biospherical QCP-2300 underwater PAR sensor | QCP2300HP sn 70440 | - | 2012-03-7 | Downward facing sensor |
| Fluorometer | WETLabs ECO-FLNTU combined fluorometer and turbidity sensor | FLNTURTD-2526 | - | 2011-12-27 | - |
| Turbidity Meter | WETLabs ECO-FLNTU combined fluorometer and turbidity sensor | FLNTURTD-2526 | - | 2011-12-27 | - |
| Altimeter | - | 56156 | - | 2012-03-22 | - |
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.
WETLabs ECO FLNTU fluorescence and turbidity sensor
The Environmental Characterization Optics (ECO) Fluorometer and Turbidity (FLNTU) sensor is a dual wavelength, single-angle instrument that simultaneously determines chlorophyll fluorescence and turbidity. It is easily integrated in CTD packages and provides a reliable turbidity measurement that is not affected by Colored Dissolved Organic Matter (CDOM) concentration.
The FLNTU can operate continuously or periodically and has two different types of connectors to output the data. There are 5 other models that operate the same way as this instrument but have slight differences, as stated below:
- FLNTU(RT) - has an analog an RS-232 serial output and operates continuously, when power is supplied
- FLNTU(RT)D - similar to the FLNTU(RT) but has a depth rating of 6000 m
- FLNTUB - has internal batteries for autonomous operation
- FLNTUS - has an integrated anti-fouling bio-wiper
- FLNTUSB - has the same characteristics as the FLNTUS but with internal batteries for autonomous operation
Specifications
| Temperature range | 0 to 30°C |
| Depth rating | 600 m (standard) 6000 m (deep) |
| Turbidity | |
| Wavelength | 700 nm |
| Sensitivity | 0.01 NTU |
| Typical range | 0.01 to 25 NTU |
| Fluorescence | |
| Wavelength | 470 nm (excitation), 695 nm (emission) |
| Sensitivity | 0.01 µg L-1 |
| Typical range | 0.01 to 50 µg L-1 |
| Linearity | 99% R2 |
Further details can be found in the manufacturer's specification sheet.
Biospherical Instruments Log Quantum Cosine Irradiance Sensor QCP-2300 & QCP-2350
The QCP-2300 is a submersible cosine-collector radiometer designed to measure irradiance over Photosynthetically Active Radiation (PAR) wavelengths. It features a constant (better than ±10%) quantum response from 400 to 700 nm with the response being sharply attenuated above 700 nm and below 400 nm.
The sensor is a blue-enhanced high stability silicon photovoltaic detector with dielectric and absorbing glass filter assembly. The output is a DC voltage typically between 0 and 5 VDC that is proportional to the log of the incident irradiance.
The QCP-2300 is specifically designed for integration with 12-bit CTD systems and dataloggers requiring a limited-range of signal input.
Specifications
| Wavelength | 400 to 700 nm |
| PAR Spectral Response | better than ± 10% over 400-700 nm |
| Cosine Directional Response | ± 5% 0 to 65°; ± 10% 0 to 85° |
| Noise level | < 1 mV |
| Temperature Range | -2 to 35 °C |
| Depth Range (standard) | 1000 m |
Further details can be found in the manufacturer's manual.
.CTD data collected from the GEOTRACES Angeles Alvarino MedSeA (GA04S) cruise in the Mediterranean Sea: Originators Processing
Responsible investigator
Dr Jordi García Orellana
email: jordi.garcia@uab.cat
Independent University of Barcelona
Institute of Science and Environmental Technology
Office C3/342. 08193 Bellaterra. Spain
Prof. Patrizia Ziveri
email: patrizia.ziveri@uab.cat
Independent University of Barcelona
Institute of Science and Environmental Technology
Office C3/342. 08193 Bellaterra. Spain
Data contributors
Dr Jordi García Orellana
email: jordi.garcia@uab.cat
Independent University of Barcelona
Institute of Science and Environmental Technology
Office C3/342. 08193 Bellaterra. Spain
Laboratory of analysis
Institute of Science and Environmental Technology
Originator's Protocol for Data Acquisition and Analysis
The Spanish GEOTRACES cruise GA04S (MedSeA cruise) in the Mediterranean Sea on board the B/O Ángeles Alvariño started in Cadiz on 2 May 2013 and finished in Barcelona on 1 June 2013. It was divided in two legs with one stop in Heraklion (Crete). Large volume water samples were collected from 11 stations, 6 of them during the first leg (Gibraltar, Alboran, Southern Alguero-Balear, Sardine Strait, Southern Ionian Sea and Eastern Basin) and 5 stations during the second part of the cruise (Tyrrherian Sea, Northern Alguero-Balear Basin, Central Alguero-Balear Basin and the Catalano-Balear Sea).
All CTD data was processed using standard SeaBird processing routines, software version Seasave V 7.21k. The CTD data were recorded with a frequency of 24 data cycles per second. A bottle file was produced from the up cast for each CTD. The raw CTD data were processed, averaged every 5 meters from top to bottom (except for CTD 3: every 1 meter) and combined into one Excel file.
Where two probes were used to measure the same parameter the accuracy of the probes were checked. If the difference for the same measurement was too big (3 times the accuracy of the system), then the 2 values were removed from the final dataset.
All sensors had manufacturer calibrations applied before the cruise.
Data Quality Report
SeaDataNet criteria was used - http://www.seadatanet.org/content/download/18414/119624/file/SeaDataNet_QC_procedures_V2_(May_2010).pdf
CTD data collected from the GEOTRACES Angeles Alvarino MedSeA (GA04S) cruise in the Mediterranean Sea: Processing by BODC
The data arrived at BODC in one Excel file containing data from CTD casts representing all of the CTD casts taken during the cruise. Data were reformatted to BODC internal QXF format (subset of NetCDF).
The originator's variables were mapped to appropriate BODC parameter codes as detailed in the table below.
| Originator's Parameter Name | Units | Description | BODC Parameter Code | BODC Units | Comments |
|---|---|---|---|---|---|
| CTDPRS | Decibars (dbar) | Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level | PRESPR01 | Decibars (dbar) | - |
| CTDTEMP (ITS-90) | Degrees Celsius (°C) | Temperature of the water body by CTD or STD | TEMPST01 | Degrees Celsius (°C) | Average of primary and secondary sensor |
| CTDSAL | Dimensionless | Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm | PSALST01 | Dimensionless | Calculated from both conductivity sensors |
| CTDOXY | Micromoles per kilogram (µmol/Kg) | Concentration of oxygen {O2 CAS 7782-44-7} per unit mass of the water body [dissolved plus reactive particulate phase] | DOXMZZXX | Micromoles per kilogram (µmol/Kg) | Calibrated by discrete samples using the Winkler titration method. |
| FLUORESCENCE | Milligrams per cubic metre (mg/m3) | Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate phase] by in-situ chlorophyll fluorometer and manufacturer's calibration applied | CPHLPM01 | Milligrams per cubic metre (mg/m3) | - |
| TURBIDITY | Nephelometric Turbidity Units (NTU) | Turbidity of the water body by in-situ optical backscatter measurement and laboratory calibration against formazin | TURBPR01 | Nephelometric Turbidity Units (NTU) | - |
| PAR, IRRADIANCE | Watt per square meter (W/m^2) | Downwelling vector irradiance as energy (PAR wavelengths) in the water body by cosine-collector radiometer | DWIRRXUD | Watt per square meter (W/m^2) | Sub-surface PAR |
| SPAR, SURF IRRADIANCE | Watt per square meter (W/m^2) | - | - | - | Surface PAR - Not transferred |
| CPAR CORRECTED IRRADIANCE % | Percent (%) | Proportion of sub-surface irradiance (PAR wavelengths) {Percent light depth} | PCTIRRXX | Percent (%) | CPAR = 100 * A * (underwater PAR)/(surface PAR) where A is the scaling factor used for comparing light fields of disparate intensity. |
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
GEOTRACES
Introduction
GEOTRACES is an international programme sponsored by SCOR which aims to improve our understanding of biogeochemical cycles and large-scale distribution of trace elements and their isotopes (TEIs) in the marine environment. The global field programme started in 2009 and will run for at least a decade. Before the official launch of GEOTRACES, fieldwork was carried out as part of the International Polar Year (IPY)(2007-2009) where 14 cruises were connected to GEOTRACES.
GEOTRACES is expected to become the largest programme to focus on the chemistry of the oceans and will improve our understanding of past, present and future distributions of TEIs and their relationships to important global processes.
This initiative was prompted by the increasing recognition that TEIs are playing a crucial role as regulators and recorders of important biogeochemical and physical processes that control the structure and productivity of marine ecosystems, the dispersion of contaminants in the marine environment, the level of greenhouse gases in the atmosphere, and global climate.
Scientific Objectives
GEOTRACES mission is: To identify processes and quantify fluxes that control the distribution of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions.
Three overriding goals support the GEOTRACES mission
- Determine ocean distributions of selected TEIs at all major ocean basins
- Evaluate the sources, sinks, and internal cycling of these TEIs and thereby characterize more completely their global biogeochemical cycles
- Provide a baseline distribution in the Polar Regions as reference for assessing past and future changes.
These goals will be pursued through complementary research strategies, including observations, experiments and modelling.
Fieldwork
The central component of GEOTRACES fieldwork will be a series of cruises spanning all Ocean basins see map below.
Three types of cruise are required to meet the goals set out by GEOTRACES. These are
- Section cruises - These will measure all the key parameters (see below) over the full depth of the water column. The sections were discussed and approved by the International GEOTRACES Scientific Steering Committee at the basin workshops.
- Process Studies - These will investigate a particular process relevant to the cycling of trace metal and isotopes. They must follow the "Criteria for Establishing GEOTRACES Process Studies" and be approved by the International GEOTRACES Scientific Steering Committee.
- Cruises collecting GEOTRACES compliant data - These will collect some trace element or isotope data. They must follow the GEOTRACES Intercalibration and Data Management protocols
IPY-GEOTRACES
The IPY-GEOTRACES programme comprised of 14 research cruises on ships from 7 nations; Australia, Canada, France, Germany, New Zealand, Japan and Russia. The cruises will not be classified in the same way as the full GEOTRACES programme since the intercalibration protocols and data management protocols had not been established before the start of the IPY. But IPY-GEOTRACES data will still be quality controlled by GDAC and in the majority of cases verified versus Intercalibration standards or protocols.
Key parameters
The key parameters as set out by the GEOTRACES science plan are as follows: Fe, Al, Zn, Mn, Cd, Cu; 15N, 13C; 230Th, 231Pa; Pb isotopes, Nd isotopes; stored sample, particles, aerosols.
Weblink:
http://www.bodc.ac.uk/geotraces/
http://www.geotraces.org/
Data Activity or Cruise Information
Cruise
| Cruise Name | MedSeA2013 (GA04S) |
| Departure Date | 2013-05-02 |
| Arrival Date | 2013-06-01 |
| Principal Scientist(s) | Jordi GarcĂa Orellana (Independent University of Barcelona Institute of Science and Environmental Technology), Patrizia Ziveri (Independent University of Barcelona Institute of Science and Environmental Technology) |
| Ship | Angeles Alvarino |
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 |
