Metadata Report for BODC Series Reference Number 1097622

• 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

Bathymetry data measured by the ship's echo sounder are very sparse throughout the cruise.

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

Ashtech Global Positioning System receivers (ADU series)

The ADU series of Global Positioning System (GPS) receivers are designed to give real-time three-dimensional position and attitude measurements. Attitude determination is based on differential carrier phase measurements between four antennas connected to a receiver, providing heading, pitch and roll, along with three-dimensional position and velocity.

The ADU2 model receives information from 48 channels, while the upgraded model (ADU5) uses 56 channels. The ADU5 also features a unique Kalman filter with user selectable dynamic modes to match operating conditions. It also incorporates signals from Satellite Based Augmentation Systems (SBAS) and features an embedded 2-channel 300 kHz beacon receiver for easy differential GPS (DGPS) operations.

Specifications

Further details can be found in the manufacturer's specification sheets for the ADU2 andADU5.

Chernikeeff Aquaprobe Mk5 Electromagnetic Speed Log

The Aquaprobe Mk5 EM Speed Log operates on the principle that a conductor (such as water) passing through an electromagnetic field will create a voltage whose magnitude increases as the speed of the conductor increases. The EM log includes one or two hull-mounted transducers, which generate an electromagnetic field and measure the voltage created by the flow of water through that field, thereby deducing the speed of the vessel through the water.

The EM log has the options of single or twin transducers, single or dual axis speed measurements and gate-valved (retractable) hull fitting or fixed transducers. The microprocessor calibration control ensures a high accuracy through the entire speed range.

Specifications

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

UK SOLAS Discovery Cruise D317 Underway Meteorology and Surface Hydrography Document

Underway data for D317 were provided to BODC by NMF-SS personnel.

Instrumentation

Navigation and bathymetry

Meteorology

Surface hydrography

Originator's Data Processing

Raw data were logged to NetCDF format through the ship's Techsas system. Data were converted to RVS binary format on a daily basis, for manual data processing, including merging the navigation streams, deriving absolute winds and salinity, and correcting bathymetric depth data. Data were supplied to BODC in Techsas NetCDF, RVS binary, and also RVS listit ASCII formats.

Navigation and bathymetry

Three GPS systems were used on the ship. These are treated hierarchically, with two used as backups to the first. The standard processing software, Bestnav, identifies gaps in the preferred GPS stream, and fills them with data from the second choice stream, and then, if necessary, the third choice.

Meteorology

Meteorological data were collected from sensors mounted at 18.5 m height on the foremast platform. The ship's heading and course over ground were used to correct relative wind data to absolute values.

Surface hydrography

The surface water component consisted of a flow through system with a pumped pickup at 5 m depth. The TSG was set to a flow rate of 25 L/min, and the fluorometer and transmissometer to a flow rate of 3 L/min. The TSG housing temperature and conductivity were used to derive salinity.

BODC Data Processing

All parameters were visually screened, and spikes flagged as suspect. Screening took into account comparisons between different parameters, and the environmental context.

Navigation and bathymetry

Bestnav latitude and longitude had some gaps, even where the raw GPS channels were continuous. These included two major data losses, attributed to failures of the Techsas system 00:00-09:44 02/04/2007 and 00:00-15:57 07/04/2007. BODC filled these gaps with concurrent data from the Fugro G12 GPS. The position data were used to generate ship speeds, which were in turn screened for improbable values in order to identify small spikes in latitude and longitude. Any remaining small gaps were filled by interpolation.

Bathymetric data from the echo sounder were screened in comparison with GEBCO bathymetry.

Meteorology

BODC applied manufacturers' calibrations to the pyranometers and PAR sensors. Port and starboard PAR were merged, taking the maximum measured value from the pair for each cycle, to eliminate the ship's shading effect. Port and starboard TIR were merged in the same way.

Wind data were screened with reference to the ship's heading, to account for the sheltering effect of the ship. Air temperature data were also screened with reference to heading, to identify instances of stack pollution.

Sea surface hydrography

TSG salinity was calibrated against independent bottle sample salinity data. A calibration data set of 16 data pairs was analysed. There was no significant trend in instrument response with time, and there was a simple, very small offset between bottle salinity and TSG salinity. BODC has therefore applied a mean offset calibration to the TSG salinity:

PSALSG01 = PSALSU01 - 7.5 x 10^-5 (BODC calibration 6289)

No independent measurements were made with which to calibrate the in situ fluorometer. This parameter has been left as the raw instrument output voltage.

Quality control report

Navigation and bathymetry

Bathymetry data from the echosounder were very sparse.

Meteorology

No data quality issues to report.

Sea surface hydrography

No data quality issues to report.

Project Information

Surface Ocean Lower Atmosphere Study

The Surface Ocean-Lower Atmosphere Study (SOLAS) is an international research initiative comprising over 1500 scientists in 23 countries. Its central goal is to understand the biogeochemical-physical interactions between the ocean and atmosphere, and how their coupling affects, and is affected by climate change.

UK SOLAS, Field Observations of Sea Spray, Gas Fluxes and Whitecaps (SEASAW)

This project was led by the University of Leeds, in association with the National Oceanography Centre, Southampton, and the University of the Highlands and Islands.

Sea spray aerosol particles, generated primarily by the action of the wind on the ocean surface, make a major contribution to the atmospheric aerosol over the global oceans. Their ability to participate in heterogeneous atmospheric chemical processes and especially their activity as cloud condensation nuclei make them very important in global climate processes. Similarly, the air-sea fluxes of trace gases, are influenced by wind speed and whitecap processes. The flux of carbon dioxide between atmosphere and ocean is a controlling factor on the concentration of CO2 in the atmosphere, but there are large uncertainties in the size of the flux as a function of wind speed; and the effects of factors such as wave breaking, surfacants, etc are almost entirely unknown.

SEASAW aimed to measure gas and particle fluxes across the air-sea interface by direct eddy-covariance methods and other techniques in order to determine their dependence on environmental factors.

Fieldwork comprised one dedicated open ocean research cruise: D317, and participation in another UK SOLAS cruise: D313. The observational data include:

• sea state, whitecapping and wave breaking
• bubble properties
• air-sea gas fluxes
• aerosol properties

More detailed information on this project may be found in the official cruise reports for D313 and D317.

NE/C001869/1

Project Page

Funding: UKRI Gateway to Research

UK Surface Ocean Lower Atmosphere Study

The UK Surface Ocean Lower Atmosphere Study (UK SOLAS) is the UK's contribution to the international SOLAS programme.

UK SOLAS formed interdisciplinary teams to address three primary aims

• To determine the mechanisms controlling rates of chemical transfer and improve estimates of chemical exchanges
• To evaluate the impact of these exchanges on the biogeochemistry of the surface ocean and lower atmosphere and on feedbacks between the ocean and atmosphere
• To quantify the impacts of these boundary layer processes on the global climate system

UK SOLAS started in 2003, to run for seven years. The programme was funded by the Natural Environment Research Council.

Funded projects

In total, 19 projects have been funded by UK SOLAS, over four funding rounds.

UK SOLAS has also supported ten tied studentships, and two CASE studentships.

Fieldwork

UK SOLAS fieldwork has included eight dedicated research cruises in the North Atlantic Ocean. Continuous measurements were made aboard aboard the Norwegian weather ship, Polarfront, until her decommission in 2009. Time series have been established at the SOLAS Cape Verde Observatory, and at the Plymouth Marine Laboratory L4 station. Experiments have taken place at the Bergen mesocosm facility.

A series of collaborative aircraft campaigns have added complementary atmospheric data. These campaigns were funded by UK SOLAS, African Monsoon Multidisciplinary Analyses (AMMA-UK), Dust and Biomass Experiment (DABEX) and the Facility for Airborne Atmospheric Measurements (FAAM).

Weblink: http://www.nerc.ac.uk/research/programmes/solas/

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: