Metadata Report for BODC Series Reference Number 808256


Metadata Summary

Data Description

Data Category Surface temp/sal
Instrument Type
NameCategories
Falmouth Scientific Instruments OEM conductivity-temperature sensor  water temperature sensor; salinity sensor
Falmouth Scientific Instruments ocean temperature module  water temperature sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Stuart Cunningham
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) Rapid Climate Change Programme
RAPIDMOC
 

Data Identifiers

Originator's Identifier CD170_PRODQXF_SURF
BODC Series Reference 808256
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2005-04-02 17:29
End Time (yyyy-mm-dd hh:mm) 2005-04-22 15:51
Nominal Cycle Interval 120.0 seconds
 

Spatial Co-ordinates

Start Latitude 28.48130 N ( 28° 28.9' N )
End Latitude 24.19630 N ( 24° 11.8' N )
Start Longitude 15.71070 W ( 15° 42.6' W )
End Longitude 49.76270 W ( 49° 45.8' 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 Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed 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
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
TEMPHU01 1 Degrees Celsius UncalTSGHullTmp Temperature of the water body by thermosalinograph hull sensor and NO 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

Falmouth Scientific Inc. OEM CT sensor

The OEM CT sensor is designed to provide high accuracy conductivity and temperature measurements in a package that can be readily integrated into user systems. The CT sensor relies on an inductively coupled conductivity sensor, with a large inside diameter that eliminates the need for pumps. A high grade Platinum Resistance Thermometer is used to measure temperature.

Sensor specifications are given in the table below. Since 2009 this instrument has been manufactured by Teledyne RD Instruments as a Citadel CT-EK Sensor. More information about the instrument can be found on the Teledyne Citadel specification sheet .

Sensor Specifications

Instrument Parameter Small CT Cell Conductivity Large CT Cell Conductivity Temperature
Range 0 to 70 mS cm -1 0 to 70 mS cm -1 -2 to 35 degrees C
Accuracy ±0.020 mS cm -1 ±0.010 mS cm -1 ±0.050 degrees C
Stability ±0.005 mS cm -1 mo -1 ±0.003 mS cm -1 ±0.005 degrees C mo -1
Response 20 cm @ 1 m s -1 15 cm @ 1 m s -1 20 seconds internal, 1 second external

Power Input 50 mW @ 6 VDC, voltage range 6 - 14 VDC
Logic 2 0 - 5 VDC control lines
Output Impedance 500 ohms

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 .

RAPID Cruise CD170 Surface Hydrography Instrument Details

The surface meteorology and thermosalinograph measurements were made by the RSU/UKORS Surfmet system. The depth of the ship's intake is 2.5 m. The instruments used, together with their serial numbers and manufacturer are listed below.

Sensor Serial number Last calibration date
FSI OCM housing conductivity sensor 1376 Calibration stored internally
FSI OTM housing temperature sensor 1340 25/06/2002
FSI OTM remote temperature sensor 1348 June 2003

RAPID Cruise CD170 Sea Surface Hydrography, Meteorology and Navigation

Cruise details

Dates 2 - 27 April 2005
Principal Scientific Officer Dr Stuart Cunningham (SOC)

The data series supplied by the originator covers 02/04/2005 to 22/04/2005, which is less than the duration of the cruise.

A full copy of the Metadata report can be found here: CD170

Data Aquisition and Onboard Processing

Onboard processing was carried out on a daily basis and involved running a sequence of executable programs. The initial stage transferred the underway surfmet data into PSTAR from RVS format. Subsequent processing included the calculation of salinity and the merging of the different data streams (heading, bestnav, gyro and ash-gyro). An additional executable was run to determine the true wind speed and direction, taking account of the ship's motion and velocity.

BODC Underway Data Processing Procedures

All sea surface hydrographic, navigation and meteorological data were transferred from Matlab format into BODC internal format (QXF). Reformatting and data calibration was carried out, and is discussed in the individual instrument sections. Each data channel was visually inspected and any spikes or periods of dubious data flagged as suspect using the BODC in house visualisation tool EDSERPLO. The capabilities of the workstation screening software allows all possible comparative screening checks between channels (e.g. to ensure corrected wind data have not been influenced by changes in ship's heading). The system also has the facility of simultaneously displaying the data and the ship's position on a map to enable data screening to take oceanographic climatology into account.

The qxf file then underwent a further step. This involved using Matlab to split the qxf file into three separarte qxf files. One contained data for hydrography, one for meterological data and the final qxf file held the navigation data.

RAPID Cruise CD170 Surface Hydrography Processing

Salinity

The underway salinity channel was calibrated by the data originator using independent bottle salinity samples drawn from the ship's uncontaminated water supply at 4 hour intervals.

Calibration was achieved with a combination of PSTAR and Matlab routines. Bottle salinity data (.csv files) were transferred to the ship's Unix system and appended into one file. Salinities were converted back to conductivities and merged underway conductivity data using the time variable. The discrete bottle samples with matching salinities were used to compute a salinity difference that was filtered and added to the surface salinities.

Temperature

Sea surface temperature has not been calibrated against another source. Attempts were made at BODC to use CTD temperature, averaged over the top 2.5 m as a source of verification. However, there were only three resulting points. The offset (CTD temperature minus underway sea surface temperature) was examined. One of the points had a large offset and the underway component had a large standard deviation associated with it; therefore it was discarded. The remaining two points (mean offset of -0.03, standard deviation 0.002) were not deemed sufficient to base a calibration upon.


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.


Monitoring the Meridional Overturning Circulation at 26.5N (RAPIDMOC)

Scientific Rationale

There is a northward transport of heat throughout the Atlantic, reaching a maximum of 1.3PW (25% of the global heat flux) around 24.5°N. The heat transport is a balance of the northward flux of a warm Gulf Stream, and a southward flux of cooler thermocline and cold North Atlantic Deep Water that is known as the meridional overturning circulation (MOC). As a consequence of the MOC northwest Europe enjoys a mild climate for its latitude: however abrupt rearrangement of the Atlantic Circulation has been shown in climate models and in palaeoclimate records to be responsible for a cooling of European climate of between 5-10°C. A principal objective of the RAPID programme is the development of a pre-operational prototype system that will continuously observe the strength and structure of the MOC. An initiative has been formed to fulfill this objective and consists of three interlinked projects:

The entire monitoring array system created by the three projects will be recovered and redeployed annually until 2008 under RAPID funding. From 2008 until 2014 the array will continue to be serviced annually under RAPID-WATCH funding.

The array will be focussed on three regions, the Eastern Boundary (EB), the Mid Atlantic Ridge (MAR) and the Western Boundary (WB). The geographical extent of these regions are as follows:

References

Baehr, J., Hirschi, J., Beismann, J.O. and Marotzke, J. (2004) Monitoring the meridional overturning circulation in the North Atlantic: A model-based array design study. Journal of Marine Research, Volume 62, No 3, pp 283-312.

Baringer, M.O'N. and Larsen, J.C. (2001) Sixteen years of Florida Current transport at 27N Geophysical Research Letters, Volume 28, No 16, pp3179-3182

Bryden, H.L., Johns, W.E. and Saunders, P.M. (2005) Deep Western Boundary Current East of Abaco: Mean structure and transport. Journal of Marine Research, Volume 63, No 1, pp 35-57.

Hirschi, J., Baehr, J., Marotzke J., Stark J., Cunningham S.A. and Beismann J.O. (2003) A monitoring design for the Atlantic meridional overturning circulation. Geophysical Research Letters, Volume 30, No 7, article number 1413 (DOI 10.1029/2002GL016776)


Data Activity or Cruise Information

Cruise

Cruise Name CD170
Departure Date 2005-04-02
Arrival Date 2005-04-27
Principal Scientist(s)Stuart A Cunningham (Southampton Oceanography Centre)
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