Metadata Report for BODC Series Reference Number 739021


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Nortek Aquadopp 3D doppler current meter  current meters; water temperature sensor
Instrument Mounting subsurface mooring
Originating Country United States
Originator Prof Bill Johns
Originating Organization Rosenstiel School of Marine and Atmospheric Science
Processing Status banked
Project(s) MOCHA
 

Data Identifiers

Originator's Identifier 36706/1136
BODC Series Reference 739021
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2005-05-14 00:00
End Time (yyyy-mm-dd hh:mm) 2006-10-06 00:00
Nominal Cycle Interval 43200.0 seconds
 

Spatial Co-ordinates

Latitude 26.49550 N ( 26° 29.7' N )
Longitude 76.49967 W ( 76° 30.0' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 811.5 m
Maximum Sensor Depth 811.5 m
Minimum Sensor Height 4028.5 m
Maximum Sensor Height 4028.5 m
Sea Floor Depth 4840.0 m
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 Approximate - Depth is only approximate
 

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)
ACYCAA01 1 Dimensionless Record_No Sequence number
LCEWEL01 1 Centimetres per second CurrVelE_CM Eastward current velocity (Eulerian) in the water body by in-situ current meter
LCNSEL01 1 Centimetres per second CurrVelN_CM Northward current velocity (Eulerian) in the water body by in-situ current meter
PRSTPR01 1 Decibars MidWat_TotPress Pressure (measured variable) exerted by the water body plus atmosphere by semi-fixed in-situ pressure sensor
TEMPPR01 1 Degrees Celsius Temp Temperature 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


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

Nortek Aquadopp Open Water Current Meter

This instrument provides 3D acoustic doppler current measurements along with standard measurements of temperature, pressure, tilt and direction. It can be used in real time measurement situations or can log to an internal recorder powered by internal batteries. It can also be configured to measure surface wave height, period and direction concurrently. It has the unique feature of being run in 'diagnostic' mode when set to collect data at 1 Hz frequency in user specified intervals. This allows studies of mooring motion and the performance of other current meters to be conducted. It can be set in various configurations with titanium housings for deployment at greater depths.

Standard Measured Parameters

Surface wave monitoring

The standard Aquadopp is suitable for measuring surface wave height, period, and direction, which are calculated using the PUV method whereby spectra are estimated based on a combination of the pressure signal recorded by the instrument (P) and two horizontal components of the wave orbital velocity (U and V). More specifically, the pressure signal is used to provide an estimate of the wave frequency spectrum. The energy in this spectrum is then used to estimate wave height and period. The measurements of the wave orbital velocities are used to provide an estimate of the wave direction. Since these estimates are based on the distribution of wave energy and are not direct measurements of the free surface, they should be considered inferred estimates.

Both the dynamic pressure and the orbital velocities are driven by surface waves. The signals that are associated with these properties are complicated by the fact that they attenuate (that is the signals are weaker) with depth. The exact behaviour of the attenuation is determined by the water depth and the wavelength being observed. The greater the water depth the greater the attenuation; likewise, the shorter the wavelength (or higher the frequency of the wave) the greater the attenuation for a given water depth. This means that the estimation of wave parameters is limited by both water depth and wave frequency.

Specifications

Water Velocity Measurement
Range ± 5 m/s (standard 300 m version)
± 3 m/s (3000 m and 6000 m versions - higher ranges available on request)
Accuracy 1% of measured value ± 0.5 cm/s
Max. sampling rate 1 Hz, 4 Hz also available on request (standard version)
Internal sampling rate 23 Hz
Measurement Area
Measurement cell size 0.75 m
Measurement cell position 0.35 - 5.0 m
Default position 0.35 - 1.8 m
Doppler uncertainty (noise)
Typical 0.5 - 1.0 cm/s
At 1 Hz sampling rate 1.5 cm/s
Echo Intensity
Acoustic frequency 2 MHz
Resolution 0.45 dB
Dynamic range 90 dB
Sensors
Temperature Thermistor embedded in head
Range -4°C to 40°C
Accuracy/resolution 0.1°C / 0.01°C
Time response 10 min
Compass Magnetometer
Accuracy/Resolution 2° / 0.1° for tilt < 20°
Tilt Liquid level
Maximum tilt 30°
Up or down Automatic detect
Pressure Piezoresistive
Range 0 - 300 m (standard), 0 - 3000 m or 0 - 6000 m
Accuracy/resolution 0.5%
Analogue Inputs
No. of channels 2
Voltage supply 12 V
Voltage input 16 bit A/D
Materials
Standard version Delrin with titanium screws
3000 m version Delrin with titanium screws
6000 m version Titanium with Delrin transducer head
Environmental
Operating temperature -4°C to 40°C
Dimensions
Cylinder 568 mm x 75 mm (standard)
619 mm x 84 mm (3000 m version)
625 mm x 84 mm (6000 m version)
Weight in air 3.5 kg (standard)
3.6 kg (3000 m version)
7.6 kg (6000 m version)
Weight in water Neutral (standard)
1.2 kg (3000 m version)
4.8 kg (6000 m version)

Further details can be found in the manufacturer's specification sheets for the Aquadopp , Aquadopp 3000 and Aquadopp 6000 .

RAPIDMOC/MOCHA Current Meter data processing document

This document outlines the procedures undertaken to process and quality assure current meter data collected under the RAPIDMOC and MOCHA projects.

Originator's processing

The raw data are downloaded from the instrument and converted to ASCII format.

Once in ASCII format the data are corrected for the following -

A 40 hour low pass filter is also applied to the data.

Calculating and applying calibrations

Manufacturers calibrations are applied.

Quality Control

Data were visually inspected for out-lying data and instrument electrical spikes removed.

BODC processing

Data are received after quality checks have been made and calibrations have been applied. The data files are submitted in ASCII format as one file per instrument.

Once the submitted data files are safely archived, the data undergo reformatting and banking procedures:

Parameter mapping

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

Identifier Unit Definition BODC parameter code Units Unit conversion Comments
YY year Year AADYAA01 days - Combined with MM and DD to form a date and transferred
MM month Month AADYAA01 days - Combined with MM and DD to form a date and transferred
DD day Day AADYAA01 days - Combined with MM and DD to form a date and transferred
HH hour Decimal hours AAFDZZ01 days /24 Transferred
T °C Temperature TEMPPR01 °C - Transferred
P dbar Pressure PRSTPR01 dbar - Transferred
U cm/s Eastward velocity LCEWEL01 cm/s - Transferred
V cm/s Northward velocity LCNSEL01 cm/s - Transferred

Project Information

Meridional Overturning Circulation and Heatflux Array (MOCHA) Project

Introduction

Users of these data are referred to the Meridional Overturning Circulation and Heatflux Array (MOCHA) Project Website for more information. The following text has been taken from the website.

Scientific Rationale

To set in place a system for continuous observation of the meridional heat transport in the subtropical Atlantic, with which to document its variability and its relationship to oberved climate fluctuations, and to assess climate model predictions

Overview

MOCHA is a collaborative project, partnered with the UK RAPID Program, to measure the heat and freshwater transports of the North Atlantic Ocean. These transports are called the Thermohaline or Overturning Circulation. Simply put, warm waters move poleward at the surface of the ocean, where they cool and sink, to return equatorward in the deep ocean.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2005-05-13
End Date (yyyy-mm-dd) 2006-10-06
Organization Undertaking ActivityRosenstiel School of Marine and Atmospheric Science
Country of OrganizationUnited States
Originator's Data Activity IdentifierWB3#2
Platform Categorysubsurface mooring

RAPID Moored Instrument Rig WB3#2

This rig was deployed as part of the Western Boundary (WB) array of the MOCHA/RAPIDMOC project.

Deployment cruise RV Knorr cruise KN182_2
Recovery cruise RV Seward Johnson cruise SJ14-06

The rig was anchored by 5200lbs of railway wheels and was kept erect by a large sub-surface float supplemented by groups of smaller buoyancy glass floats attached throughout the mooring.

Instruments deployed on the rig

Depth Instrument
60m Sea-Bird SBE37 SMP MicroCAT (#486)
100m SonTek Argonaut MD current meter (#D293)
114m Sea-Bird SBE37 SMP MicroCAT (#482)
267m Sea-Bird SBE37 SMP MicroCAT (#483)
401.1m Nortek Aquadopp current meter (#1123)
413m Sea-Bird SBE37 SMP MicroCAT (#3165)
611m Sea-Bird SBE37 SMP MicroCAT (#485)
811.5m Nortek Aquadopp current meter (#1136)
813m Sea-Bird SBE37 SMP MicroCAT (#3167)
1012m Sea-Bird SBE37 SMP MicroCAT (#3859)
1209.6m Nortek Aquadopp current meter (#1138)
1211m Sea-Bird SBE37 SMP MicroCAT (#3164)
1608m Sea-Bird SBE37 SMP MicroCAT (#3860)
2011m Sea-Bird SBE37 SMP MicroCAT (#3168)
2018.7m Nortek Aquadopp current meter (#1144)
2511m Sea-Bird SBE37 SMP MicroCAT (#3861)
3009m Sea-Bird SBE37 SMP MicroCAT (#3163)
3025.5m Nortek Aquadopp current meter (#1148)
3503m Sea-Bird SBE37 SMP MicroCAT (#3862)
4003m Sea-Bird SBE37 SMP MicroCAT (#3863)
4031.4m Nortek Aquadopp current meter (#1156)
4492m Sea-Bird SBE37 SMP MicroCAT (#3864)
5000m Sea-Bird SBE37 SMP MicroCAT (#3865)

No data were recorded by instruments SonTek Argonaut MD #D293 and Sea-Bird SBE37 SMP MicroCAT #3865. Instrument Sea-Bird SBE37 SMP MicroCAT #486 was lost and no data are expected.

Other Series linked to this Data Activity - 812882 813001 813013 812894 739057 812913 739033 812925 812962 812974 812998 812901 812937 739045 739069 812986 812949 812950 739008

Cruise

Cruise Name KN182_2
Departure Date 2005-05-02
Arrival Date 2005-05-26
Principal Scientist(s)William E Johns (Rosenstiel School of Marine and Atmospheric Science)
Ship RV Knorr

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameWestern Boundary Array
CategoryOffshore area
Latitude26° 37.50' N
Longitude73° 37.50' W
Water depth below MSL

RAPIDMOC/MOCHA Western Boundary (WB) Array

The Western Boundary Array defines a box in which moorings were deployed at the western side of the North Atlantic as part of the RAPIDMOC project and the collaborative project Meridional Overturning Circulation and Heatflux Array (MOCHA). The box region has latitudinal limits of 26° N to 27.5° N and longitudinal limits of 69.5° W to 77.5° W. Moorings have occupied this region since 2004 and are typically deployed for 6 to 18 months.

Moored data summary

Year Cruise ID Number of moorings Data types (number of instruments)
2004 D278 9 (6 RAPIDMOC, 3 MOCHA) ADCP (2), BPR (8), CM (29), MCTD (52), MMP (1)
2005 KN182_2 11 (6 RAPIDMOC, 5 MOCHA) ADCP (2), BPR (6), CM (27), MCTD (56)
2006 RB06-02, SJ14-06 11 (6 RAPIDMOC, 5 MOCHA) ADCP (1), BPR (3), CM (22), IES (7), MCTD (60)
2007 RB07-01 7 (7 RAPIDMOC) ADCP (1), BPR (4), CM (16), MCTD (47)
2008 SJ08-03 11 (8 RAPIDMOC, 3 MOCHA) ADCP (2), BPR (3), CM (40), MCTD (80)
2009 RB0901, D344, D345 16 (11 RAPIDMOC, 5 MOCHA) ADCP (2), BPR (5), CM (39), MCTD (91), DVS (1)
2010 OC459-1, RB1009 9 (8 RAPIDMOC, 1 MOCHA) ADCP (1), BPR (7), CM (23), MCTD (54)
2011 KN200-4 7 (7 RAPIDMOC, 6 MOCHA) ADCP (2), BPR (7), CM (43), MCTD (86), DVS (1), IES (1)
2012 RB1201, EN517, D382 24 (19 RAPIDMOC, 5 MOCHA) ADCP (3), BPR (19), CM (74), MCTD (130), IES(1)
2014 JC103 24 (9 RAPIDMOC) BPR (8), CM (22), MCTD (36)

Cruise data summary

During the cruises to service the moored array, a variety of data types are collected. The table below is a summary of these data. The number of CTD profiles performed on these cruises within the box region defined above is also included. Trans-Atlantic hydrographic CTD sections have also been performed since 2004 and are included in the table.

Cruise ID Cruise description Data types Number of CTD profiles performed within the box region
D277 Initial array deployment DIS, MET, NAV, SADCP, SURF 1
D278 Initial array deployment DIS, MET, NAV, SADCP, SURF 16
D279 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 31
KN182_2 Array service CTD, DIS, MET, NAV, SADCP, SURF 64
RB0601 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 39
SJ14-06 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 33
RB07-01 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 36
SJ08-03 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 33
RB0901 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 35
D344 Array service CTD, DIS, MET, NAV, SADCP, SURF 3
D345 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 24
OC459-1 Array service CTD, DIS, MET, NAV, SADCP, SURF 9
OC459-2 Western Boundary Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 27
D346 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 31
RB1009 WB4 service CTD, MET, SURF, NAV 2
KN200-4 Array service CTD, DIS, MET, NAV, SURF 34
RB1201 Array service CTD, DIS, MET, NAV, SURF 10
EN517 Array service CTD, DIS, LADCP, MET, NAV, SURF 31
D382 Array service CTD, DIS, MET, NAV, SURF 8
JC103 Array service CTD, DIS, MET, NAV, SURF 7

Data type ID and description

Data type ID Description
ADCP Acoustic Doppler Current Profiler
BATH Bathymetry
BPR Bottom Pressure Recorder
CM Current Meter
CTD Conductivity-Temperature-Depth profiler
DIS Discrete water bottle samples
DVS Doppler Volume sampler
IES Inverted Echo Sounder
LADCP Lowered Acoustic Doppler Current Profiler
MET Meteorology
MCTD Moored Conductivity-Temperature-Depth sensor
MOCTD Moored Conductivity-Temperature-Depth Oxygen sensor
MMP McLane Moored Profiler - profiling CTD and current meter
NAV Navigation
SADCP Shipborne Acoustic Doppler Current Profiler
SURF Sea surface data

Other Series linked to this Fixed Station for this cruise - 738828 738841 738853 738865 738877 738889 738890 738908 738921 738933 738945 738957 738969 738970 738982 738994 739008 739033 739045 739057 739069 739070 739082 739094 739101 739113 739125 739137 739149 774528 774541 774553 774565 774577 774589 774590 774608 774621 774633 774645 774657 774669 774670 774682 774694 774701 774713 774725 774737 774749 812882 812894 812901 812913 812925 812937 812949 812950 812962 812974 812986 812998 813001 813013 813025 813037 813049 813050 813062 813074 813086 813098 813105 813117 813129 813130 813142 813154 813166 813178 946204 946216 946253 946265 1137318 1137331

Other Cruises linked to this Fixed Station (with the number of series) - D278 (90) D344 (10) D345 (43) D346 (31) D382 (85) EN517 (11) JC103 (9) KN200-4 (135) OC459-1 (64) RB0602 (42) RB0701 (58) RB0901 (78) RB1009 (24) RB1201 (91) SJ-08-03 Leg 1 (39) SJ-08-03 Leg 2 (76) SJ-14-06 (62)


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