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Metadata Report for BODC Series Reference Number 1040718


Metadata Summary

Data Description

Data Category Offshore sea floor pressure series
Instrument Type
NameCategories
Paroscientific 410K Pressure Transducer  water temperature sensor; water pressure sensors
Instrument Mounting fixed benthic node
Originating Country United Kingdom
Originator Dr Chris Hughes
Originating Organization Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Rapid Climate Change Programme
RAPID-WAVE
 

Data Identifiers

Originator's Identifier B0RL#1/93170
BODC Series Reference 1040718
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2004-08-18 19:37
End Time (yyyy-mm-dd hh:mm) 2006-07-31 20:52
Nominal Cycle Interval 900.0 seconds
 

Spatial Co-ordinates

Latitude 42.99737 N ( 42° 59.8' N )
Longitude 60.90958 W ( 60° 54.6' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 1835.0 m
Maximum Sensor or Sampling Depth 1835.0 m
Minimum Sensor or Sampling Height 1.0 m
Maximum Sensor or Sampling Height 1.0 m
Sea Floor Depth 1836.0 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor or Sampling Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum Approximate - Depth is only approximate
 

Parameters

BODC CODERankUnitsTitle
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
ACYCAA011DimensionlessSequence number
PPSRPS011MillibarsPressure (measured variable) exerted by the water body by fixed in-situ pressure sensor and expressed to unspecified datum by subtraction of a constant
PRSTRD011DecibarsPressure (residual) exerted by the water body plus atmosphere by fixed in-situ pressure sensor and subtraction of value predicted by tidal analysis without correction for drift
PRSTRS011DecibarsPressure (residual) exerted by the water body plus atmosphere by fixed in-situ pressure sensor and subtraction of value predicted by tidal analysis
TEMPPR011Degrees CelsiusTemperature of the water body

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

RAPID WAVE Data Quality Report

The recorded pressure data were particularly noisy. The originator flagged cycles which differed from the average of neighbouring cycles by more than 1 mbar. In addition, a small number of clear anomalies were also flagged. These originator-flagged cycles have been mapped to BODC 'replacement value' flags (26849 flags assigned to each pressure series) and 'interpolated value' flags (189 flags assigned to each pressure series) accordingly. In total, there are 68358 data cycles in each channel.

The first 3 hours 15 minutes of temperature data have been flagged suspect by BODC - it is apparent that the sensor was still adjusting following deployment during this period.


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

Paroscientific Absolute Pressure Transducers Series 3000 and 4000

Paroscientific Series 3000 and 4000 pressure transducers use a Digiquartz pressure sensor to provide high accuracy and precision data. The sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.

The 3000 series of transducers includes one model, the 31K-101, whereas the 4000 series includes several models, listed in the table below. All transducers exhibit repeatability of better than ±0.01% full pressure scale, hysteresis of better than ±0.02% full scale and acceleration sensitivity of ±0.008% full scale /g (three axis average). Pressure resolution is better than 0.0001% and accuracy is typically 0.01% over a broad range of temperatures.

Differences between the models lie in their pressure and operating temperature ranges, as detailed below:

Model Max. pressure (psia) Max. pressure (MPa) Temperature range (°C)
31K-101 1000 6.9 -54 to 107
42K-101 2000 13.8 0 to 125
43K-101 3000 20.7 0 to 125
46K-101 6000 41.4 0 to 125
410K-101 10000 68.9 0 to 125
415K-101 15000 103 0 to 50
420K-101 20000 138 0 to 50
430K-101 30000 207 0 to 50
440K-101 40000 276 0 to 50

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

RAPID WAVE bottom pressure data processing document

This document outlines the procedures undertaken to process and quality assure the Bottom Pressure data collected under the RAPID WAVE project.

Originator's processing

The raw data are downloaded from the instrument and converted to ASCII format. All processing is performed in Matlab.

Processing

Processing steps which are undertaken include

  • calculation of pressure anomaly from the pressure record by subtraction of a mean pressure. See the series-specific documents for further information.

  • tidal analysis performed by least-squares fitting to the good sections of each data series. Removal of diurnal and shorter duration tides, but not monthly or fortnightly tides.

  • calculation of residual pressure by subtracting the fitted tide from the pressure anomaly.

  • detrending the residual pressure (exponential plus linear trend removed following Watts and Kontoyiannis, J. Atm. Oceanic Tech. (7). 1990.

Quality control

Removal of suspect data cycles was performed by the originator. Suspect data included isolated anomalies, periods of instrumental noise or absent data. Flags were assigned to good series data (Flag=0), to data gaps which were filled by replacement data (plus bias and trend) from neighbouring pressure instruments (Flag=1) and instances of data gaps filled by linear interpolation of detided, detrended pressures (Flag=2).

BODC processing

The data files are submitted to BODC in ASCII format as one file per instrument. Once safely archived, the data undergo reformatting and banking procedures:

  • The data are transferred into a common format, a netCDF subset.

  • Data flags 1 are mapped to BODC replacement 'R' flags. Data flags 2 are mapped to BODC interpolated 'T' flags.

  • Standard parameter codes are assigned to each channel that accurately describe the data (see Parameter mapping section below).

  • Unit conversions are applied, if necessary, so that units are standardised (see Parameter mapping section below).

  • The data are screened visually and any spikes or instrument malfunctions can be clearly labelled with quality control flags.

  • Comprehensive documentation is prepared describing the collection, processing and quality of each data series.

  • Detailed metadata and documents are loaded to the database and linked to each series so that the information is readily available to future users.

Parameter mapping

The following describes the parameters contained in the originator's files and their mapping to BODC parameter codes :

Originator's variable Originator's units BODC parameter code BODC parameter definition BODC units Unit conversion Comments
Temperature deg C multiplied by 100 TEMPPR01 Temperature of the water body deg C /100 -
Observed pressure (above a reference value) millibars PPSRPS01 Pressure (measured variable) exerted by the water body by fixed in-situ pressure sensor and expressed to unspecified datum by subtraction of a constant millibars - Pressure offsets/reference values for each series are documented elsewhere
Residual pressure millibars PRSTRD01 Pressure (residual) exerted by the water body plus atmosphere by fixed in-situ pressure sensor and subtraction of value predicted by tidal analysis without correction for drift decibars /100 -
Predicted pressure millibars Data not transferred by BODC - - - -
Trend fitted to pressure millibars Data not transferred by BODC - - - -
Detrended residual pressure millibars PRSTRS01 Pressure (residual) exerted by the water body plus atmosphere by fixed in-situ pressure sensor and subtraction of value predicted by tidal analysis decibars /100 -

RAPID WAVE bottom pressure mean offset: Series 1040718

The pressure anomaly for this pressure record was obtained by subtracting 290547 mbar from the absolute pressure recorded by the instrument.


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

  • To establish a pre-operational prototype system to continuously observe the strength and structure of the Atlantic Meridional Overturning Circulation (MOC).
  • To support long-term direct observations of water, heat, salt, and ice transports at critical locations in the northern North Atlantic, to quantify the atmospheric and other (e.g. river run-off, ice sheet discharge) forcing of these transports, and to perform process studies of ocean mixing at northern high latitudes.
  • To construct well-calibrated and time-resolved palaeo data records of past climate change, including error estimates, with a particular emphasis on the quantification of the timing and magnitude of rapid change at annual to centennial time-scales.
  • To develop and use high-resolution physical models to synthesise observational data.
  • To apply a hierarchy of modelling approaches to understand the processes that connect changes in ocean convection and its atmospheric forcing to the large-scale transports relevant to the modulation of climate.
  • To understand, using model experimentation and data (palaeo and present day), the atmosphere's response to large changes in Atlantic northward heat transport, in particular changes in storm tracks, storm frequency, storm strengths, and energy and moisture transports.
  • To use both instrumental and palaeo data for the quantitative testing of models' abilities to reproduce climate variability and rapid changes on annual to centennial time-scales. To explore the extent to which these data can provide direct information about the thermohaline circulation (THC) and other possible rapid changes in the climate system and their impact.
  • To quantify the probability and magnitude of potential future rapid climate change, and the uncertainties in these estimates.

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.


RAPID Western Atlantic Variability Experiment (WAVE)

Introduction

The RAPID WAVE project began in 2004 as an observational component of the U.K Natural Environment Research Council's RAPID Climate Change Programme in the western North Atlantic Ocean. In 2008, funding to continue RAPID WAVE was secured through the continuation programme, RAPID-WATCH, which is due to end in 2014.

The RAPID WAVE team brings together scientists at the National Oceanography Centre in Liverpool. Between 2004 and 2010, the RAPID WAVE team also contributed to the Line W mooring array, joining colleagues from the U.S. Line W is a U.S-led initiative used to monitor the North Atlantic Ocean's deep western boundary current whilst being funded through the U.S National Science Foundation and has been active since October 2001. It brings together scientists from Woods Hole Oceanographic Institution (WHOI) and Lamont-Doherty Earth Observatory (LDEO). Users of these data are referred to the Line W Project Website for more information.

In 2007, further collaboration was established with scientists at the Bedford Institute of Oceanography (BIO). This arrangement was formalised and continues under RAPID-WATCH. Smaller scale collaboration with scientists at the Instituto Espanol de Oceanografia (IEO) during RAPID-WATCH saw additional RAPID WAVE observational work in the eastern North Atlantic Ocean. This work commenced in 2009 as part of the RAPID WAVE RAPIDO campaign.

Scientific Rationale

The primary aim of the RAPID WAVE project is to develop an observing system that will identify the propagation of overturning signals, from high to low latitudes, along the western margin of the North Atlantic. It specifically aims to monitor temporal changes in the Deep Western Boundary Current and reveal how coherent the changes are along the slope. Ultimately it is envisaged that this will enable scientists to develop a better understanding of larger-scale overturning circulation in the Atlantic, and its wider impacts on climate.

Fieldwork

The fieldwork aspect of the project was to deploy arrays of Bottom Pressure Recorders (BPRs) and CTD moorings along specified satellite altimeter groundtracks off the eastern continental slope of Canada and the United States. In 2004, fieldwork focused on three array lines. Line A was established heading south west from the Grand Banks, whilst the Line B array ran south east on the continental slope of Nova Scotia. The third line, Line W, was an established hydrographic array on the continental slope of New England, serviced by Woods Hole Oceanographic Institute (WHOI), to which RAPID WAVE contributed BPR instrumentation.

The original intention was that each array would be serviced by a cruise every two years. However, following a very poor return rate of instrumentation during the first servicing cruise of Lines A and B in 2006, this plan was modified significantly, and the decision made to abandon work on Line A. In 2007, additional logistical support from Canada's Bedford Institute of Oceanography (BIO) enabled Line B to be serviced again after just one year of deployment, with a much improved recovery record.

The transition from RAPID to RAPID-WATCH funding marked significant changes to the RAPID WAVE observational system. Line B was abandoned and a joint array with BIO, known as the RAPID Scotia Line, to the south west was developed. This line receives annual servicing by BIO, with cruise participation from the RAPID WAVE team.

The servicing of RAPID WAVE BPRs on Line W remained a biennial activity during the RAPID and RAPID-WATCH programmes.

A small number of BPR deployments have also taken place off the coast of Spain as part of the RAPIDO element of RAPID WAVE.

Instrumentation

Types of instruments and measurements:

  • Moored BPRs
  • Moored CTD/CT loggers
  • Moored current meters (RAPID-WATCH)
  • Moored ADCPs (RAPID-WATCH)
  • Shipboard measurements: CTD, underway, salinity, LADCP, ADCP

Contacts

Collaborator Organisation Project
Prof. Chris M. Hughes National Oceanography Centre, U.K RAPID WAVE
Dr. Miguel Angel Morales Maqueda National Oceanography Centre, U.K RAPID WAVE
Dr. Shane Elipot National Oceanography Centre, U.K RAPID WAVE
Dr. John M. Toole Woods Hole Oceanographic Institution, U.S Line W
Dr. Igor Yashayaev Bedford Institute of Oceanography, Canada -

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2004-08-18
End Date (yyyy-mm-dd) 2006-08-01
Organization Undertaking ActivityProudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierB0RL#1
Platform Categoryfixed benthic node

RAPID Moored Instrument Lander B0RL#1

This benthic lander was deployed as part of the Line B array of the RAPID WAVE project.

Deployment cruise RRS Charles Darwin Cruise CD160
Recovery cruise RRS Discovery Cruise D308

Instrumentation

Depth Platform and Instrument
1836 m POL RapidLander (RL14) Bottom Pressure Recorder (BPR) sensor DQ93170

Cruise

Cruise Name CD160
Departure Date 2004-08-04
Arrival Date 2004-08-24
Principal Scientist(s)Mike Meredith (Proudman Oceanographic Laboratory)
Ship RRS Charles Darwin

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameRAPID WAVE Site B0
CategoryOffshore location
Latitude42° 59.84' N
Longitude60° 54.57' W
Water depth below MSL1838.0 m

RAPID Mooring Site B0

This fixed station forms part of the Line B mooring array located to the east of Halifax, Nova Scotia, deployed as part of the RAPID WAVE project.

Period of collection August 2004 - September 2008

Site occupations

Mooring identifier Mooring type Deployment date Recovery date Parameters measured
B0RL#1 RapidLander 18 Aug 2004    01 Aug 2006 Pressure and temperature
B0RL#2 RapidLander 01 Aug 2006 29 Sep 2008 Pressure and temperature

Related Fixed Station activities are detailed in Appendix 1


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
Q value below limit of quantification

Appendix 1: RAPID WAVE Site B0

Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.

Series IdentifierData CategoryStart date/timeStart positionCruise
1070081CTD or STD cast2006-08-01 06:30:0043.005 N, 60.92333 WRRS Discovery D308
1040731Offshore sea floor pressure series2006-08-01 20:07:3042.999 N, 60.90967 WRRS Discovery D308