Metadata Report for BODC Series Reference Number 679532


Metadata Summary

Data Description

Data Category Surface temp/sal
Instrument Type
NameCategories
SeaTech transmissometer  transmissometers
WETLabs WETStar fluorometer  fluorometers
Falmouth Scientific Instruments ocean temperature module  water temperature sensor
Ashtech ADU2 Global Positioning System receiver  NAVSTAR Global Positioning System receivers
Trimble 4000DL Global Positioning System receiver  Differential Global Positioning System receivers
Falmouth Scientific Instruments ocean conductivity module  salinity sensor
Ashtech G12 Global Positioning System receiver  NAVSTAR Global Positioning System receivers; Differential Global Positioning System receivers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Prof Nick McCave
Originating Organization University of Cambridge Department of Earth Sciences
Processing Status banked
Project(s) Rapid Climate Change Programme
 

Data Identifiers

Originator's Identifier CD159_SURF
BODC Series Reference 679532
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2004-07-01 08:30
End Time (yyyy-mm-dd hh:mm) 2004-07-29 14:41
Nominal Cycle Interval 30.0 seconds
 

Spatial Co-ordinates

Southernmost Latitude 49.37200 N ( 49° 22.3' N )
Northernmost Latitude 63.14433 N ( 63° 8.7' N )
Westernmost Longitude 53.12817 W ( 53° 7.7' W )
Easternmost Longitude 4.86300 W ( 4° 51.8' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 2.5 m
Maximum Sensor Depth 2.5 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Scattered at fixed depths - The sensors are scattered with respect to depth but each remains effectively at the same depth for the duration of the series
Sensor Depth Datum Approximate - Depth is only approximate
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
ATTNMR01 1 per metre Atten_red Attenuation (red light wavelength) per unit length of the water body by 20 or 25cm path length transmissometer
FVLTWS01 1 Volts WsVolt Instrument output (voltage) by linear-response chlorophyll fluorometer
PSALSG01 1 Dimensionless P_sal_TSG_calib Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and calibration against independent measurements
TEMPHG01 1 Degrees Celsius CalTSGHullTmp Temperature of the water body by thermosalinograph hull sensor and verification against independent measurements
 

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

No Problem Report Found in the Database


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

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 .

Ashtech G12 Global Positioning System Receiver

The Ashtech G12 Global Positioning System (GPS) uses all-in-view tracking and 12 channels to provide real time three-dimensional positional measurements. It is Differential GPS (DGPS) ready, offering an accuracy of better than 40 cm, position latency better than 50 ms, and exact position latency to millisecond accuracy.

Specifications

Parameter Values
Operating Temperature -30°C to 70°C
Sampling frequency up to 10 Hz
Receiver channels 12
Real-Time Position Accuracy Horizontal, DGPS: 40 cm Horizontal 95%: 90 cm Vertical 95%: 1.6 m

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

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 .

SeaTech Transmissometer

Introduction

The transmissometer is designed to accurately measure the the amount of light transmitted by a modulated Light Emitting Diode (LED) through a fixed-length in-situ water column to a synchronous detector.

Specifications

Notes

The instrument can be interfaced to Aanderaa RCM7 current meters. This is achieved by fitting the transmissometer in a slot cut into a customized RCM4-type vane.

A red LED (660 nm) is used for general applications looking at water column sediment load. However, green or blue LEDs can be fitted for specilised optics applications. The light source used is identified by the BODC parameter code.

Further details can be found in the manufacturer's Manual .

CD159 Underway Instrumentation

Navigation

Meteorology

All meteorological and light sensors were mounted on the ship's foremast.

Sensor type Make and model Serial No. Comment
Air temperature and relative humidity Vaisala HMP44L S504004  
Barometric pressure Vaisala PTB100A S3440009 14.5 m above sea level
Photosynthetically active radiation (PAR) Didcot/ELE DRP-5 5143 Port
Photosynthetically active radiation (PAR) Didcot/ELE DRP-5 5144 Starboard
Solar radiation Kipp and Zonen 962276 Port
Solar radiation Kipp and Zonen 962301 Starboard
Anemometer Vaisala WAA P22306 16 m above sea level
Wind vane Vaisala WAV R21213 0/360 ° is aft.

Hydrography

Ship's intake was at approximately 2.5 m.

Sensor type Make and model Serial No. Comment
Thermosalinograph temperature FSI OTM 1361  
Remote (hull) temperature FSI OTM 1370  
Thermosalinograph conductivity FSI OCM 1358  
Flow-through transmissometer WET Labs/SeaTech T-1019D 20 cm path
Flow-through fluorometer WET Labs WS3S-134  

Falmouth Scientific Inc. Ocean Sensor Modules

FSI's individual sensor modules include an Ocean Conductivity Module (OCM), Ocean Temperature Module (OTM) and Ocean Pressure Module (OPM). All three use a low power micro-controller to collect, scale and transmit real-time data via RS-232 or RS-485.

Parameter OCM Conductivity OTM Temperature OPM Pressure
Range 0 - 7.0 S/m(0 - 70 mS/cm) -2 to 32 °C User Specified:0-200 dBar0-1000 dBar0-2000 dBar0-3000 dBar0-7000 dBar
Accuracy -0.0003* S/m(-0.003 mS/cm) -0.003 °C* -0.03% full scale*
Stability /month -0.00005 S/m(-0.0005 mS/cm) -0.0005 °C -0.002% full scale
Resolution 0.00001 S/m(-0.0001 mS/cm) 0.0001 °C 0.0004% full scale
Response at 1 m/s flow 50 msec 150 msec 25 msec
Sensor Type Inductive cell Platinum thermometer Strain gauge

* Higher accuracy available

For further details, see the manufacturer's specification sheet .

CD159 Underway General Processing

UKORS data processing

Data logging and initial data processing were handled by the RVS ABC logging system.

Standard navigation processing was carried out using the relmov and bestnav programs. relmov takes in data from the electro-magnetic (EM) speed log and gyro compass in order to generate a relative motion file. This relative motion file was then combined with one or more fix files by the bestnav program in order to generate a 10 second interval best navigation file, bestnav. The original idea behind bestnav was that it would take infrequent fixes, such as those from older transit satellite systems (typically several hours between fixes), or even fixes manually input from sextant sightings, and then dead-reckon between those fixes. Today, with GPS fixes coming in every second, its dead-reckoning facility is only used for periods when GPS drops out, for instance due to an aurora.

The program prodep was used to correct depth data from the Simrad EA-500 echo sounder for variation of sound velocity in sea water (Carter's tables corrections) and written at 10 second intervals to a file called prodep. Meteorological data were collected through a Vaisala QL150 sensor collector at 1 second intervals, which is then averaged to 30 seconds. Salinity data were derived from temperature and conductivity data logged via the Surfmet system using the protsg program.

The bestnav, prodep, rawsurfmet and protsg ASCII files were submitted to BODC for banking.

BODC processing

Problems with the logging of the data channels in the protsg file meant rawsurfmet was used as the source of all hydrographic data, as well as meteorological variables. The bestnav, prodep and rawsurfmet data files were merged at 30 second intervals using an in-house script (BUDS loadrvs) and transformed into QXF format, a subset of netCDF. Following transfer to QXF, the data were visually screened using the in-house EDSERPLO package.

Navigation

Navigation channels were checked for gaps and improbable speeds. 11 gaps were found, all less than 1 minute duration, which were filled using linear interpolation. No speed check errors were found.

The following unit conversions were made:

CD159 Underway Hydrography

Hydrography Processing Notes


Project Information

Rapid Climate Change (RAPID) Programme

Rapid Climate Change (RAPID) is a £20 million, six-year (2001-2007) programme of the Natural Environment Research Council (NERC). The programme aims to improve our ability to quantify the probability and magnitude of future rapid change in climate, with a main (but not exclusive) focus on the role of the Atlantic Ocean's Thermohaline Circulation.

Scientific Objectives

Projects

Overall 38 projects have been funded by the RAPID programme. These include 4 which focus on Monitoring the Meridional Overturning Circulation (MOC), and 5 international projects jointly funded by the Netherlands Organisation for Scientific Research, the Research Council of Norway and NERC.

The RAPID effort to design a system to continuously monitor the strength and structure of the North Atlantic Meridional Overturning Circulation is being matched by comparative funding from the US National Science Foundation (NSF) for collaborative projects reviewed jointly with the NERC proposals. Three projects were funded by NSF.

A proportion of RAPID funding as been made available for Small and Medium Sized Enterprises (SMEs) as part of NERC's Small Business Research Initiative (SBRI). The SBRI aims to stimulate innovation in the economy by encouraging more high-tech small firms to start up or to develop new research capacities. As a result 4 projects have been funded.


Data Activity or Cruise Information

Cruise

Cruise Name CD159
Departure Date 2004-07-01
Arrival Date 2004-07-30
Principal Scientist(s)I Nicholas McCave (University of Cambridge Department of Earth Sciences)
Ship RRS Charles Darwin

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