Metadata Report for BODC Series Reference Number 1786195

• 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

Problem Reports

Wind sensors

Throughout the time series there appears to be suspect dips in true wind speed when the relative wind direction changes. It was unclear why this was occurring and might be due to the sensitivity of the sensor during lower wind speeds. BODC have therefore flagged all wind channels. (BODC assessment)

RRS Discovery cruise DY051 meteorology quality control report

Wind sensors

There are areas in this time series when the true wind speed show signs of shielding. Shielding occurs when the sensor is partially blocked from the wind by the ship. (BODC assessment)

Light sensors

All PAR and TIR channels display consistent negative readings during night time. This most likely results from excessive loss of radiation after sunset, which suggests that day-time data recorded during cloud cover should also be treated with caution. Another explanation would be that outdated calibrations added an offset to the data. All negative PAR and TIR data were flagged. (BODC assessment)

There was a noticeable offset between the two TIR channels. No values have been flagged. (BODC assessment)

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

Gill Instruments Windsonic Anemometer

The Gill Windsonic is a 2-axis ultrasonic wind sensor that monitors wind speed and direction using four transducers. The time taken for an ultrasonic pulse to travel from the North to the South transducers is measured and compared with the time for a pulse to travel from South to North. Travel times between the East and West transducers are similarly compared. The wind speed and direction are calculated from the differences in the times of flight along each axis. This calculation is independent of environmental factors such as temperature.

Specifications

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

Kipp and Zonen Pyranometer Model CM6B

The CM6B pyranometer is intended for routine global solar radiation measurement research on a level surface. The CM6B features a sixty-four thermocouple junction (series connected) sensing element. The sensing element is coated with a highly stable carbon based non-organic coating, which delivers excellent spectral absorption and long term stability characteristics. The sensing element is housed under two concentric fitting Schott K5 glass domes.

Specifications

RRS Discovery cruise DY051 meteorology instrumentation

Instrumentation

The meteorological suite of sensors was located on the forecastle deck, at approximately 17.4 m above sea level. The anemometer orientation was 0° on the bow.

Skye Instruments PAR Energy Sensor Model SKE 510

The SKE 510 is suitable for measuring photosynthetically active radiation (PAR) from natural or artificial light sources. The sensor is fully waterproof and guaranteed submersible to 4m depth, and indoor versions are also available.

The instrument uses a blue-enhanced planar diffused silicon detector to measure energy (in W m^-2) over the 400-700 nm waveband. It has a cosine-corrected head and a square spectral response. The sensor can operate over a temperature range of -35 to 70 °C and a humidity range of 0-100% RH.

Specifications

Vaisala PTB110 barometer

An industrial, analog barometer which uses a silicon capacitive sensor (BAROCAP). The sensor produces either frequency or voltage output and is mountable on a (35 mm wide) DIN rail.

Operating ranges (1 hPa = 1 mbar)

General

Accuracy

* Defined as ±2 standard deviation limits of end-point non-linearity, hysteresis error or repeatability error.
** Defined as ±2 standard deviation limits of inaccuracy of the working standard including traceability to NIST.
*** Defined as the root sum of the squares (RSS) of end-point non-linearity, hysteresis error, repeatability error and calibration uncertainty at room temperature when using voltage output.

More detailed information can be found in the manufacturer's data sheet and user's guide.

Vaisala Temperature and Relative Humidity HMP Sensors

A family of sensors and instruments (sensors plus integral displays or loggers) for the measurement of air temperature and relative humidity. All are based on a probe containing a patent (HUMICAP) capacitive thin polymer film capacitanece humidity sensor and a Pt100 platinum resistance thermometer. The probes are available with a wide range of packaging, cabling and interface options all of which have designations of the form HMPnn or HMPnnn such as HMP45 and HMP230. Vaisala sensors are incorporated into weather stations and marketed by Campbell Scientific.

All versions operate at up to 100% humidity. Operating temperature ranges vary between models, allowing users to select the version best suited to their requirements.

Further details can be found in the manufacturer's specification sheets for the HMP 45 series, HMP 70 series and HMP 230 series.

RRS Discovery cruise DY051 meteorology data processing procedures

Originator's Data Processing

The data were logged by the TECHSAS (TECHnical and Scientific sensors Acquisition System) version 5.9 data logging system into daily NetCDF files which were provided to BODC for processing. Data was additionally logged into the RVS Level-C format which have been archived at BODC.

Files delivered to BODC

BODC Data Processing

The data were reformatted to BODC internal format using standard banking procedures. Data were averaged at 60 second intervals. The following table shows how variables within the file were mapped to appropriate BODC parameter codes:

yyyymmdd-090000-MET-DY-SM_DY1.SURFMETv2

yyyymmdd-090000-Light-DY-SM_DY1.SURFMETv2

All data expressed at measurement altitude.

Calibrations

Field Calibrations

No field calibrations were applied to the data at BODC.

Manufacturers Calibrations

PAR/TIR

The following manufacturer's calibrations were applied to the PAR and TIR light sensors using:

y (W m ^-2 ) = (a x 10 ⁶ )/b

where 'a' is the raw data in volts and 'b' is the calibration offset (µV per W m ^-2 ) as shown below.

All the reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag.

Absolute wind speed and direction

Relative wind speed and direction were corrected for the ship's heading and speed using the POS MV gyro heading, ship velocities (calculated at BODC from the main positional channels) and an anemometer orientation of 0° on the bow, thus obtaining the BODC derived absolute wind speed and direction parameters, with codes EWSBSS01 and EWDASS01 respectively.

Air pressure

A manufacturer's calibration was not applied to the barometer because there was no significant offset reported on the certified calibration certificate.

Air temperature and humidity

Manufacturer's calibrations were not applied to the temperature and humidity probe because there were no significant offsets reported on the certified calibration certificate.

Project Information

MAC-EXP: Development of a pressurised sampling, experimentation and cultivation system for deep-sea sediments

MAC-EXP is an 3 year project that aims to develop a flexible, cost-effective alternative to in situ experimentation: a pressure-coring, experimentation and cultivation system that enables studies of deep-sea prokaryote biodiversity and ecosystem functioning, under ambient or manipulated pressure, temperature and oxygen conditions from any medium sized ocean going research ship with coring capability. This Multiple-Autoclave-Coring and Experimentation system (MAC-EXP) will aim to provide the possibility to systematically test the influence of environmental parameters, such as pressure, oxygen availability or pH on deep-sea organisms and their biochemistry, as well as on rates and pathways of biogeochemical and geomicrobial processes. The system will also aim to allow pioneering work in the field of marine biodiscovery: secondary metabolites from marine microorganisms are a rich source of chemical diversity and several marine-microbe derived compounds are now in clinical trials.

The research aims to develop techniques to retrieve pressurised cores from the deep sea and maintain them at sea floor pressures whilst on the surface to enable manipulative experimentation and cultivation, providing a real alternative to cost adverse in-situ sampling and manipulation techniques such as ROVs, manned submersibles and sophisticated Landers, while at the same time avoiding depressurisatio during sampling, experimentation and cultivation.

The project is led by the University of Aberdeen, Institute of Biological and Environmental Science and is a collaboration with the University of Cardiff, School of Earth and Ocean Sciences and the Technical University Berlin. The project received funding from the Natural Environmental Research Council and runs between February 2013 and December 2016.

Data Activity or Cruise Information

Cruise

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:

SeaDataNet Quality Control Flags

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