Metadata Report for BODC Series Reference Number 1102607
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
Data Description |
|||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||
Data Identifiers |
|||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||
Time Co-ordinates(UT) |
|||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||
Spatial Co-ordinates | |||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||
Parameters |
|||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||
|
Problem Reports
No Problem Report Found in the Database
Data Access Policy
GEOTRACES - data access conditions
Access to this data is currently restricted and it is not available via BODC's normal delivery mechanisms.
GEOTRACES data are published via the GEOTRACES IDP, available at:
Narrative Documents
Satlantic and MBARI In Situ Ultraviolet Spectrophotometer ISUS, ISUS V2 and ISUS V3
The ISUS series of instruments are submersible sensors that use ultraviolet absorption spectroscopy to measure in situ dissolved chemical species. Absorption spectra are measured by illuminating a sample of seawater with UV light and analysing the signal with a UV spectrometer. The calibration process embedded in the system creates a library of absorption spectra for the main absorbing species in this region of the spectrum. An optimization process adjusts the concentrations of the calibrated species spectra until the computed spectrum matches the measured one.
The original ISUS was developed by the Monterey Bay Aquarium Research Institute (MBARI) as a means of measuring nitrate, bromide and bisulfide in the ocean using in situ ultraviolet spectrometry, as described in Johnson and Coletti (2002). This prototype was superseded by the commercially available Satlantic MBARI-ISUS V2, which was developed jointly by MBARI and Satlantic, and was specifically designed to measure nitrate concentrations. The latest version is the Satlantic ISUS V3, which is also designed for nitrate measurements.
The ISUS V2 provides multiple interfaces and the data can be output in analog (for easy interface with CTD systems), digital telemetry (concentration only; the full spectral output is in ASCII or binary) or digital (stored on an internal flash card) format. This instrument can be powered internally or from external sources. The ISUS V3 has full USB capability and a Windows-based program to download files, setup schedules, log and view data. Specifications for the V2 and V3 are presented below and are the same for both models, unless otherwise stated.
Specifications
Resolution | ± 0.05 µM |
Accuracy | V2: ± 2 µM or 2% of reading, whichever is larger V3: ± 2 µM (0.028 mg l-1) or 10% of reading, whichever is larger |
Range | V2: up to 2000 µM V3: 0.5 to 2000 µM (0.007 to 28 mg l-1) |
Sample rate | 1 Hz |
Depth rating | 1000 m (200 m optional for V3 only) |
Operating temperature | V2: 0 to 35°C V3: 0 to 40°C |
Path length | 1 cm |
Wavelength range | 200 to 400 nm |
Lamp type | Deuterium |
Lamp life time | V2: 1000 hours to 50% intensity at 240 nm V3: 900 hours |
Thermal compensation | 0 to 40°C (V3 only) |
Salinity compensation | 0 to 40 psu (V3 only) |
References
Johnson, K.S. and Coletti, L.J., 2002. In situ ultraviolet spectrophotometry for high resolution and long-term monitoring of nitrate, bromide and bisulfide in the ocean. Deep-Sea Research I, 49, 1291-1305.
Further information can be found in the manual for the ISUS V2 and the manufacturer's specification sheet for theISUS V3.
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.
0903 CTD Instrumentation
The CTD unit was a standard SeaBird 9/11 plus, mounted on a rosette equipped with 24 bottles each with a volume of 12 L. The CTD was run in real time at 24Hz, the table below lists detailed information about the various addition sensors.
Sensor | Serial Number | Calibration Date | Comments |
---|---|---|---|
Sea-Bird SBE 911plus CTD | - | - | - |
Paroscientific Digiquartz depth sensors | 0730 | 12-Apr-2005 | - |
Sea-Bird SBE 4C conductivity sensor | 2696 | 27-Mar-09 | - |
Sea-Bird SBE 3plus (SBE 3P) temperature sensor | 4204 | 28-Mar-09 | - |
Sea-Bird SBE 43 Dissolved Oxygen Sensor | 0240 | 17-Apr-09 | - |
WET Labs {Sea-Bird WETLabs} C-Star transmissometer | CST-671DR | 16-Jun-2006 | - |
Seapoint chlorophyll fluorometer | 2900 | 01-May-09 | - |
Satlantic {Sea-Bird} ISUS V3Â Nitrate Sensor | 132 | - | The sensor was removed between CTD casts 14-45. |
Biospherical Instruments QCP-2300 underwater PAR sensor | 4664 | 04-Aug-09 | - |
Biospherical Instruments QCR-2200 surface PAR | 20147 | 08-Apr-2009 | - |
Dr. Haardt Back Scat CDOM fluorometer | 12030 | - | - |
Some information is unavailable
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.
Dr Haardt BackScat I fluorometer
The Dr Haardt BackScat I is a backscatter fluorometer designed to detect concentrations of a variety of substances in the water column. The instrument uses a Xe-flashlight source and exhibits a fast response and low power consumption. Integrated turbidity and other sensors are available and the instrument has a titanium housing rated to a maximum depth of 6000 m.
Each fluorometer is custom-built to measure substances of interest. Available spectral ranges are visible, UV I and UV II. A range of filter units are available for the measurement of chlorophyll-a, phycoerythrin, humic acids, aromatic hydrocarbons, phenol, oils, rhodamine B, sulforhodamine, fluorescein, eosin, pyranin and naphthionate.
Seapoint Chlorophyll Fluorometer
The Seapoint Chlorophyll Fluorometer (SCF) is a low power instrument for in situ measurements of chlorophyll a. The SCF uses modulated blue LED lamps and a blue excitation filter to excite chlorophyll a. The fluorescent light emitted by the chlorophyll a passes through a red emission filter and is detected by a silicon photodiode. The low level signal is then processed using synchronous demodulation circuitry which generates an output voltage proportional to chlorophyll a concentration. The SCF may be operated with or without a pump.
Sensor specifications, current at August 2006, are given in the table below. More information can be found at the manufacturer's web site.
Sensor Specifications
Power requirements | 8 - 20 VDC, 15 mA avg., 27 mA pk. |
---|---|
Output | 0 - 5.0 VDC |
Output Time Constant | 0.1 sec. |
Power-up transient period | < 1 sec. |
Excitation Wavelength | 470 nm CWL, 30 nm FWHM |
Emission Wavelength | 685 nm CWL, 30 nm FWHM |
Sensing Volume | 340 mm3 |
Minimum Detectable Level | 0.02 µg l-1 |
Gain | Sensitivity, V µg-1 l-1 | Range, µg l-1 | |
---|---|---|---|
Sensitivity/Range | 30x 10x 3x 1x | 1.0 0.33 0.1 0.033 | 5 15 50 150 |
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.
.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
Pathlength | 10 or 25 cm |
Wavelength | 370, 470, 530 or 660 nm |
Bandwidth | ~ 20 nm for wavelengths of 470, 530 and 660 nm ~ 10 to 12 nm for a wavelength of 370 nm |
Temperature error | 0.02 % full scale °C-1 |
Temperature range | 0 to 30°C |
Rated depth | 600 m (plastic housing) 6000 m (aluminum housing) |
Further details are available in the manufacturer's specification sheet or user guide.
CTD data for Cruise 0903 (GIPY14)
Sampling Strategy
A total of 45 CTD casts were carried out during cruise 0903, on board the CCGS Amundsen, using a stainless steel CTD frame equipped with twenty-four 12 L niskin bottles. The cruise surveyed GEOTRACES section GIPY14.
Originator's Data Processing Procedures
The data were processed using the Sea-Bird SBE Data Processing program. The quality control was based on UNESCO algorithms and was performed through matlab toolbox developed by the Maurice-Lamontagne Institute (Fisheries and Ocean Canada).
After the cruise and before the CTD data were processed the following checks were made:
1.1 The configuration files were checked to make sure all calibrations were correct.
1.2. The logbook and the rosette sheets were compared.
1.3. Bottle data summary files (extension .btl) were checked.
1.4. Metadata from the logbook, rosette sheets, and converted file headers were compared.
1.5. New calibration coefficients for SBE 43 oxygen sensor were calculated using discrete sample data taken from one cast at five different depths. The oxygen samples data were obtained using Winkler's method and a Mettler Toledo titration machine. Reagent Blanks was performed once, results showed that the chemicals were still good (m less than 4). The calibration was first checked by comparing Winkler values with CTD-DO values in the same bottle. The DO sensor calibration coefficients were then corrected. Only the downcast data was processed. The oxygen gradient in regions of high temperature gradient is still difficult to match to the temperature gradient, but this far from being unusual.
1.6. The time alignment correction for dissolved oxygen data was computed. The oxygen data must be corrected in time relative to the pressure because of the long time constant of the sensor and because of the water time transit through the pipe. The data analysis showed that a correction of 5 seconds gave the best results.
1.7. Format bottle salinity data file for CTD comparison. Samples were taken on many casts with small bottles of 200 mL which were then analysed using an autosal GuildLine, model 8400B. A total of 229 autosal measurements were used for the comparison with the CTD data.
The CTD data were processed as follows:
2.1.Data Conversion module: Convert raw .hex or .dat data to engineering units, and store converted data in .cnv file (all data) and/or .ros file (water bottle data).
2.2. Data Extraction. This step (performed through the Matlab software) was used to eliminate useless data such as those corresponding to sensor acclimatization period (the surface soak). Also detects the main pressure spikes which are often associated by temperature and conductivity spikes. As far as the ctd 911plus is concerned, it is necessary to detect the temperature outliers and to cancel them because the temperature values are used into the module 'Cell Thermal Mass'. Moreover, major temperature spikes have an impact upon derived variables using temperature such as salinity and oxygen from SBE43.
2.3. The Wild Edit module. Was removed from the SBE Data Processing sequence in order to keep the most the original data. The outliers will be removed by the control quality sequence.
2.4. The Filter module. Was used to apply a low-pass filter on the pressure data in order to smooth high-frequency data.
2.5. The Align CTD module. The corrections (5 seconds) have been applied to align oxygen data relative to pressure. This correction allows to resolve the systematic time delay between oxygen and pressure data which is due to the long time constant of the sensor and to the time transit of the water through the pipe.
2.6. The Cell Thermal Mass module. This module concerns the conductivity parameter. It permits to remove conductivity cell thermal mass effects. It was set with the default value. Data setup:
Thermal anomaly amplitude (alpha)=0.03
Thermal anomaly time constant (1/beta)=7
2.7. The Loop Edit module. This module marks data with bad flag value when it detects a pressure slow down or reversals.
2.8. The Derive module. This module allows to compute additional oceanographic parameters.
0903 Cruise report
Further information can be found in the 0903 Cruise report.
BODC Data Processing Procedures
Data received were converted to the BODC internal format (a netCDF subset). A parameter mapping table is provided below:
Originator's Variable | Originator's Units | BODC Parameter Code | BODC Units | GEOTRACES Code | GEOTRACES Units | Comments |
---|---|---|---|---|---|---|
SBE 43 Oxygen | ml/l | DOXYSCKG | µmol/kg | CTDOXY_D_CONC_SENSOR | µmol/kg | Conversion using *43.57 |
Trans | % | POPTDR01 | % | CTDXMISS%_T_VALUE_SENSOR | % | - |
Sal | PSU | PSALCC01 | dimensionless | CTDSAL_D_CONC_SENSOR | PSS-78 | Units are equivalent. |
Par | µE/m2/s | IRRUUV01 | µE/m2/s | CTDPAR_T_VALUE_SENSOR | µE/m2/s | - |
Pres | decibar | PRESPR01 | decibar | CTDPRS_T_VALUE_SENSOR | decibar | - |
Temp | °C | TEMPST01 | °C | CTDTMP_T_VALUE_SENSOR | °C | ITS-90 |
Fluo | µg/l | CPHLPM01 | mg/m3 | CTDCHLA_T_CONC_SENSOR | mg/m3 | Units are equivalent. |
Following transfer the data were screened using BODC in-house visualisation software. Suspect data values were assigned the appropriate BODC data quality flag. Missing data values, where present, were changed to the missing data value and assigned a BODC data quality flag.
Data Quality Report
The CTD data were quality controlled by the originator. Data from each cast underwent 18 different tests before being inspected and flagged. Details of the processing and quality control can be found in the following report 'Geotraces-IOL 0903 CTD processing notes'. There was a lot of variability in the data that many profiles barely passed the quality control spike tests performed by the originators.
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 | 0903 (ArcticNet, GIPY14) |
Departure Date | 2009-08-27 |
Arrival Date | 2009-09-13 |
Principal Scientist(s) | Roger Francois (University of British Columbia Department of Earth and Ocean Sciences) |
Ship | CCGS Amundsen |
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 |