Metadata Report for BODC Series Reference Number 1097622


Metadata Summary

Data Description

Data Category Bathymetry
Instrument Type
NameCategories
Chernikeeff Aquaprobe Mk5 electromagnetic log  current meters
Trimble 4000AX Global Positioning System receiver  NAVSTAR Global Positioning System receivers
Ashtech ADU2 Global Positioning System receiver  NAVSTAR Global Positioning System receivers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Ian Brooks
Originating Organization University of Leeds School of Earth and Environment
Processing Status QC in progress
Project(s) UKSOLAS
SOLAS
UKSOLAS SEASAW
 

Data Identifiers

Originator's Identifier D317_PRODQXF_NAV
BODC Series Reference 1097622
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2007-03-21 11:41
End Time (yyyy-mm-dd hh:mm) 2007-04-12 09:01
Nominal Cycle Interval 30.0 seconds
 

Spatial Co-ordinates

Southernmost Latitude 38.56633 N ( 38° 34.0' N )
Northernmost Latitude 60.01100 N ( 60° 0.7' N )
Westernmost Longitude 26.17367 W ( 26° 10.4' W )
Easternmost Longitude 4.38350 W ( 4° 23.0' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth -
Maximum Sensor Depth -
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution -
Sensor Depth Datum -
Sea Floor Depth Datum -
 

Parameters

BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
ALATGP01 1 Degrees Lat_GPS Latitude north (WGS84) by unspecified GPS system
ALONGP01 1 Degrees Lon_GPS Longitude east (WGS84) by unspecified GPS system
APEWZZ01 1 Centimetres per second PlatformVelE Eastward velocity (over ground) of measurement platform
APNSZZ01 1 Centimetres per second PlatformVelN Northward velocity (over ground) of measurement platform
DSRNCV01 1 Kilometres Cmpval Distance travelled
HEADCM01 1 Degrees Platform_Heading Orientation (horizontal relative to true north) of measurement device {heading}
MBANUA01 1 Metres BathyDepES_1500 Sea-floor depth (below instantaneous sea level) {bathymetric depth} in the water body by echo sounder (SV=1500m/s)
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

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

Parameter ADU2 ADU5

Operational Temperature range:
Antenna
Receiver


-40°C to 65°C
-20°C to 55°C


-40°C to 65°C
-20°C to 55°C

Sampling frequency 5 Hz 5 Hz
Receiver channels 48 56

Accuracy:
Heading
Pitch/Roll


0.2° rms (dynamic) - 0.4° rms (static)
0.4° rms (dynamic) - 0.8° rms (static)


0.02° to 0.2° rms
0.04° to 0.4° rms

Circular Error Probability:
Autonomous
Differential


5.0 m
1.0 m


3.0 m
0.4 to 1.0 m

Further details can be found in the manufacturer's specification sheets for the ADU2 and ADU5 .

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

Speed Range ± 40 knots or ± 80 knots
Total distance range 0 to 99999.99 nm
System accuracy
Speed < 10 knots ± 0.02 knots
Speed > 10 knots ± 0.2%
Distance 0.02% of speed
Calibrated accuracy
Speed < 10 knots ± 0.1 knots
Speed > 10 knots ± 1%
Distance 0.02% of speed

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

Instrument Type Code Main role
Trimble Navigator 4000 GPS GPS_4000 Navigation
Ashtec G12 GPS GPS_G12 Navigation (1st choice for Bestnav)
Ashtec Attitude Detection Unit 2 GPS GPS_ASH Navigation
Gyrocompass Gyrocompass GYRONMEA Relative motion
Chernikeef Log EM Log LOG_CHF Relative motion

Meteorology

Sensor Serial Number Last calibration date
Vaisala Barometer PTB100A U1850012 or S3610008 -
Vaisala Temperature/Humidity HMP44L A2150009 -
Skye PAR (port) 28558 21/12/2004
Skye PAR (starboard) 28557 21/12/2004
Kipp & Zonen TIR CMB6 (port) 47463 22/12/2004
Kipp & Zonen TIR CMB6 (starboard) 47462 22/12/2004
Vaisala Anemometer WAA151 P50421 -
Vaisala Wind Vane WAV151 S21208 -

Surface hydrography

Sensor Serial number Last calibration date
FSI OTM Housing temperature - -
FSI OTM Remote temperature - -
FSI OCM Conductivity - -
Wetlabs Fluorometer - -
Seatech Transmissometer CST-112R 31/05/1996

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

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

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.

Project Title Short Title Principal Investigator
Impact of atmospheric dust derived material and nutrient inputs on near-surface plankton microbiota in the tropical North Atlantic Dust Eric Achterberg
The role and effects of photoprotective compounds in marine plankton - Steve Archer
Field observations of sea spray, gas fluxes and whitecaps SEASAW Ian Brooks
Factors influencing the biogeochemistry of iodine in the marine environment - Lucy Carpenter
Global model of aerosol processes - effects of aerosol in the marine atmospheric boundary layer GLOMAP Ken Carslaw
Ecological controls on fluxes of dimethyl sulphide (DMS) to the atmosphere - David Green
Dust outflow and deposition to the ocean DODO Ellie Highwood
Investigation of near surface production of iodocarbons - rates and exchanges INSPIRE Gill Malin
Reactive halogens in the marine boundary layer RHaMBLe Gordon McFiggans
The role of bacterioneuston in determining trace gas exchange rates - Colin Murrell
Measuring methanol in sea water and investigating its sources and sinks in the marine environment - Phil Nightingale
The impact of coastal upwellings on air-sea exchange of climatically important gases ICON Carol Robinson
The Deep Ocean Gas Exchange Experiment DOGEE Rob Upstill-Goddard
High wind air-sea exchanges HiWASE Margaret Yelland
Aerosol characterisation and modelling in the marine environment ACMME James Allan
3D simulation of dimethyl sulphide (DMS) in the north east Atlantic - Icarus Allen
Processes affecting the chemistry and bioavailability of dust borne iron - Michael Krom
The chemical structure of the lowermost atmosphere - Alastair Lewis
Factors influencing the oxidative chemistry of the marine boundary layer - Paul Monks

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/


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. SEASAW aimed to measure gas and particle fluxes across the air-sea interface, and 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:

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

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


Data Activity or Cruise Information

Cruise

Cruise Name D317
Departure Date 2007-03-21
Arrival Date 2007-04-12
Principal Scientist(s)Ian Brooks (University of Leeds School of Earth and Environment)
Ship RRS Discovery

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