Metadata Report for BODC Series Reference Number 1199802
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 |
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Parameters |
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Problem Reports
No Problem Report Found in the Database
AMT Bio-Optics Data Quality - Flow-through measurements
The data were screened using the BODC in-house software, Edserplo.
All parameters had 'N' flags applied during transfer for any null data. 'M' flags were automatically assigned during transfer to values outside the minimum and maximum permissable values. Data were occasionally manually flagged with 'M' during screening when the data scientist considered the data to be suspect. This included solitary spikes and periods when the instrument might be adjusting to conditions after failure, redeployment or period of null data.
The light parameters (ATTNXAC9, ABSULT01 and ABSPXAC9) regularly have periods of null data.
Data Access Policy
Academic domain data
These data have no specific confidentiality restrictions for academic 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 data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."
Narrative Documents
WET Labs WETStar Fluorometers
WET Labs WETStar fluorometers are miniature flow-through fluorometers, designed to measure relative concentrations of chlorophyll, CDOM, uranine, rhodamineWT dye, or phycoerythrin pigment in a sample of water. The sample is pumped through a quartz tube, and excited by a light source tuned to the fluorescence characteristics of the object substance. A photodiode detector measures the portion of the excitation energy that is emitted as fluorescence.
Specifications
By model:
Chlorophyll WETStar | CDOM WETStar | Uranine WETStar | Rhodamine WETStar | Phycoerythrin WETStar | |
---|---|---|---|---|---|
Excitation wavelength | 460 nm | 370 nm | 485 nm | 470 nm | 525 nm |
Emission wavelength | 695 nm | 460 nm | 530 nm | 590 nm | 575 nm |
Sensitivity | 0.03 µg l-1 | 0.100 ppb QSD | 1 µg l-1 | - | - |
Range | 0.03-75 µg l-1 | 0-100 ppb; 0-250 ppb | 0-4000 µg l-1 | - | - |
All models:
Temperature range | 0-30°C |
---|---|
Depth rating | 600 m |
Response time | 0.17 s analogue; 0.125 s digital |
Output | 0-5 VDC analogue; 0-4095 counts digital |
Further details can be found in the manufacturer's specification sheet, and in the instrument manual.
AMT Bio-Optics Instrumentation - Flow-through measurements
Instrument | Serial number | Parameter |
---|---|---|
WET Labs ECO-VSF | 061g | Total optical backscattering at 532 nm |
WET Labs WETStar fluorometer | 1048p | Chlorophyll fluorescence |
WET Labs ac-9 Spectrophotometer | 194 | Absorption and attenuation |
SeaBird SBE45 | 4530785-0102 | Temperature and Salinity |
WETLabs ECO-VSF Optical Backscatter Meter
The ECO-VSF is a scattering meter designed to measure the angular distribution of scattered radiation of the backward hemisphere. The instrument measures optical scattering at three angles (100°, 125° and 150°), providing the shape of the Volume Scattering Function (VSF) throughout the backscattering region. Interpolation and extrapolation are used to determine scattering at intermediate angles. It also provides the total backscatter coefficient between 90° and 180° by integration and extrapolation.
The ECO-VSF comes in five versions, with a variety of power options, sampling strategies and anti-fouling capabilities:
- The standard ECO-VSF configuration provides an RS-232 serial output with 4000-count range and can be programmed for continuous operation or periodic sampling.
- The ECO-VSF(RT) provides an RS-232 serial output with 4000-count range and can be programmed for continuous operation.
- The ECO-VSFS adds anti-fouling capabilities to the standard ECO-VSF.
- The ECO-VSFB is a self-recording version of the ECO-VSF with internal batteries for autonomous operation.
- The ECO-VSFSB adds anti-fouling capabilities to the ECO-VSFSB.
The specifications below are common to all versions.
Specifications
Wavelength | 470, 532 or 660 nm |
Sensitivity | 1.24x10-5 |
Typical range | ~ 0.0012-5 m-1 |
Linearity | 99 % R2 |
Temperature range | 0-30° |
Depth rating | 600 m (standard) |
Sample rate | up to 8 Hz |
Pressure sensor | optional |
Temperature sensor | optional |
Further details can be found in the manufacturer's specification sheet.
WETLabs ac-9 and ac-s Spectral Absorption and Attenuation Meters
The WETLabs ac-9 and ac-s meters measure the spectral transmittance and spectral absorption of water, allowing determination of absorption and beam attenuation coefficients. The instruments incorporate a flow-through system and a dual path configuration that permits concurrent measurement of both coefficients along a 25 cm path. The ac-9 provides measurements at nine wavelengths in the range 412-715 nm, whereas the ac-s provides measurements at >80 wavelengths from 400-730 nm.
Specifications
Parameters | ac-9 | ac-s |
---|---|---|
Temperature range | 0-30 ° | 0-30 ° |
Rated depth | 500 or 5000 m | 500 m |
Spectral range | 412-715 nm | 400-730 nm |
Band-pass | 10 nm per channel | 15 nm per channel |
Pathlength | 25 cm (optional 10 cm) | 25 cm (optional 10 cm) |
Beam cross-section | 8 mm dia. (nominal) | 8 mm dia. (nominal) |
Linearity | >=99 % R2 | >=99 % R2 |
Wavelength output | 9 | 80-90 in 4 nm steps |
Accuracy | ±0.01 m-1 | ±0.01 m-1 |
Dynamic range | 0.001-10 m-1 | 0.001-10 m-1 |
Further details can be found in the manufacturer's specification sheet.
SeaBird MicroTSG Thermosalinograph SBE 45
The SBE45 MicroTSG is an externally powered instrument designed for shipboard measurement of temperature and conductivity of pumped near-surface water samples. The instrument can also compute salinity and sound velocity internally.
The MicroTSG comprises a platinum-electrode glass conductivity cell and a stable, pressure-protected thermistor temperature sensor. It also contains an RS-232 port for appending the output of a remote temperature sensor, allowing for direct measurement of sea surface temperature.
The instrument can operate in Polled, Autonomous and Serial Line Sync sampling modes:
- Polled sampling: the instrument takes one sample on command
- Autonomous sampling: the instrument samples at preprogrammed intervals and does not enter quiescence (sleep) state between samples
- Serial Line Sync: a pulse on the serial line causes the instrument to wake up, sample and re-enter quiescent state automatically
Specifications
Conductivity | Temperature | Salinity | |
---|---|---|---|
Range | 0 to 7 Sm-1 | -5 to 35°C | |
Initial accuracy | 0.0003 Sm-1 | 0.002°C | 0.005 (typical) |
Resolution | 0.00001 Sm-1 | 0.0001°C | 0.0002 (typical) |
Typical stability (per month) | 0.0003 Sm-1 | 0.0002°C | 0.003 (typical) |
Further details can be found in the manufacturer's specification sheet.
AMT Bio-Optics - Flow-through Processing Document
Data Acquisition and Analysis
This system operates semi-continuously with water from the ship's non-toxic sea water supply Every 4-12 minutes temperature and salinity are measured (with a SeaBird sensor), chlorophyll fluorescence (WET Labs WETStar), total backscattering at 532 nm (bbtot; WET Labs ECO-VSF), acidified backscattering (bbacid; backscattering of the seawater suspension after the pH has been lowered to dissolve calcite and aragonite), and acid-labile backscattering (bb'; the difference between the bbtot and bbacid). The chlorophyll data were calibrated against sample data.
BODC Data Processing Procedures
Data were submitted to BODC as a .out file, which was then saved to the archive following BODC procedure. Date were submitted in a .out text file containing temperature, salinity and fluorescence from sea surface water from the ship's non-toxic water supply. Light absorption and attenuation were also supplied at 9 different wavelengths along with the backscattering and acid labile backscattering. Additional metadata was supplied including: cruise, latitude, longitude, date and time. The MicroSAS radiance parameters were also submitted in the same file but banked separately to the NODB.
The data were converted from the comma delimited SeaBass format into BODC internal format using a standard BODC transfer.
Parameter codes defined in BODC parameter dictionary were assigned to the variables as shown in the table below. No unit conversions were necessary as the data submitted was already units from the BODC parameter dictiionary.
Parameter Mapping Table
Originator's Parameter | Description | Units | BODC Parameter Code | Description | Units | Comments |
---|---|---|---|---|---|---|
lat | Latitude, as mentioned on the originator's file | degrees | ALATGP01 | Latitude north (WGS84) by unspecified GPS system Global Positioning System (receiver type unspecified) | degrees | N/A |
lon | Longitude, as mentioned on the originator's file | degrees | ALONGP01 | Longitude east (WGS84) by unspecified GPS system Global Positioning System (receiver type unspecified) | degrees | N/A |
bbp532 | Backscattering coefficient of particles(*) | m-1 | BS532VSF | Attenuance due to backscatter (532nm wavelength) in the water body by scattering photometer and calibration to read zero in clear water with computation from volume scatter data | m-1 | N/A |
agp | Absorption Coefficient of Gelbstoff + particles(*) | m-1 | ABSPXAC9 | Light absorbance (unspecified single wavelength) by the water body by transmissometer and calibration to read zero in clear water | m-1 | N/A |
ag | Absorption Coefficient of Gelbstoff(*) | m-1 | ABSULT01 | Light absorbance (unspecified single wavelength) per unit length of the water body dissolved plus reactive particulate <0.2 µm by transmissometer and calibration to read zero in clear water | m-1 | N/A |
cgp | Absorption Coefficient of Gelbstoff + particles(*) | m-1 | ATTNXAC9 | Attenuance (unspecified single wavelength) per unit length of the water body by transmissometer and calibration to read zero in clear water | m-1 | N/A |
wavelength | Wavelength(*) | nm | LAMBIN01 | Wavelength of electromagnetic radiation measurement | nm | N/A |
Sal | Salinity | - | PSALSU01 | Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and NO calibration against independent measurements | - | N/A |
Temp | Water temperature | degrees Celsius | TEMPSU01 | Temperature of the water body by thermosalinograph and NO verification against independent measurements | degrees Celsius | N/A |
Chl | Fluorometrically/spectrophotometrically-derived chlorophyll a(*) | mg m-3 | CPHLUT01 | Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate >unknown phase] by through-flow fluorometer plumbed into non-toxic supply and calibration against sample data. | mg m-3 | N/A |
Screening
Once transferred the reformatted data were imported into the BODC in-house visualisation software, Edserplo. Data were appropriately flagged and double checked for any anomalous results. Further details are given in the data quality report.
Project Information
Oceans 2025 Theme 10, Sustained Observation Activity 1: The Atlantic Meridional Transect (AMT)
The Atlantic Meridional Transect has been operational since 1995 and through the Oceans 2025 programme secures funding for a further five cruises during the period 2007-2012. The AMT programme began in 1995 utilising the passage of the RRS James Clark Ross between the UK and the Falkland Islands southwards in September and northwards in April each year. Prior to Oceans 2025 the AMT programme has completed 18 cruises following this transect in the Atlantic Ocean. This sustained observing system aims to provide basin-scale understanding of the distribution of planktonic communities, their nutrient turnover and biogenic export in the context of hydrographic and biogeochemical provinces of the North and South Atlantic Oceans.
The Atlantic Meridional Transect Programme is an open ocean in situ observing system that will:
- give early warning of any fundamental change in Atlantic ecosystem functionng
- improve forecasts of the future ocean state and associated socio-economic impacts
- provide a "contextual" logistical and scientific infrastructure for independently-funded national and international open ocean biogeochemical and ecological research.
The specific objectives are:
- To collect hydrographic, chemical, ecological and optical data on transects between the UK and the Falkland Islands
- To quantify the nature and causes of ecological and biogeochemical variability in planktonic ecosystems
- To assess the effects of variability in planktonic ecosystems on biogenic export and on air-sea exchange of radiatively active gases
The measurements taken and experiments carried out on the AMT cruises will be closely linked to Themes 2 and 5. The planned cruise track also allows for the AMT data to be used in providing spatial context to the Sustained Observation Activities at the Porcupine Abyssal Plain Ocean Observatory (SO2) and the Western Channel Observatory (SO10).
More detailed information on this Work Package is available at pages 6 - 9 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10
Weblink: http://www.oceans2025.org/
Data Activity or Cruise Information
Cruise
Cruise Name | JC053 (AMT20) |
Departure Date | 2010-10-12 |
Arrival Date | 2010-11-25 |
Principal Scientist(s) | Andrew Rees (Plymouth Marine Laboratory) |
Ship | RRS James Cook |
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 |