Metadata Report for BODC Series Reference Number 1016085


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 382/1138
BODC Series Reference 1016085
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2008-04-19 00:00
End Time (yyyy-mm-dd hh:mm) 2009-12-01 12:00
Nominal Cycle Interval 1200.0 seconds
 

Spatial Co-ordinates

Latitude 26.49217 N ( 26° 29.5' N )
Longitude 76.50067 W ( 76° 30.0' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 394.0 m
Maximum Sensor Depth 394.0 m
Minimum Sensor Height 4464.0 m
Maximum Sensor Height 4464.0 m
Sea Floor Depth 4858.0 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) 2008-04-18
End Date (yyyy-mm-dd) 2009-12-01
Organization Undertaking ActivityRosenstiel School of Marine and Atmospheric Science
Country of OrganizationUnited States
Originator's Data Activity IdentifierWB3#4
Platform Categorysubsurface mooring

RAPID Moored Instrument Rig WB3#4

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

Deployment cruise RV Seward Johnson cruise SJ08-03-1
Recovery cruise RRS Discovery cruise D345

The rig was anchored to the sea bed and was kept erect by a large sub-surface float supplemented by groups of smaller buoyancy all attached on titanium swivels.

Instruments deployed on the rig

Depth Instrument
60 m Sea-Bird SBE37 SMP MicroCAT (#0482)
90 m Nortek Aquadopp current meter (#1123)
100 m Sea-Bird SBE37 SMP MicroCAT (#3165)
100 m SonTek Argonaut MD current meter (#D266)
250 m Sea-Bird SBE37 SMP MicroCAT (#0483)
394 m Nortek Aquadopp current meter (#1138)
400 m Sea-Bird SBE37 SMP MicroCAT (#3865)
400 m SonTek Argonaut MD current meter (#D283)
600 m Sea-Bird SBE37 SMP MicroCAT (#0485)
800 m SonTek Argonaut MD current meter (#D308)
800 m Sea-Bird SBE37 SMP MicroCAT (#4624)
800 m SonTek Argonaut MD current meter (#D337)
1000 m Sea-Bird SBE37 SMP MicroCAT (#5872)
1207 m Nortek Aquadopp current meter (#1148)
1207 m Sea-Bird SBE37 SMP MicroCAT (#3863)
1207 m SonTek Argonaut MD current meter (#D269)
1600 m Sea-Bird SBE37 SMP MicroCAT (#3859)
2019 m Nortek Aquadopp current meter (#1136)
2019 m Sea-Bird SBE37 SMP MicroCAT (#3861)
2019 m SonTek Argonaut MD current meter (#D284)
2500 m Sea-Bird SBE37 SMP MicroCAT (#3164)
3027 m Nortek Aquadopp current meter (#1144)
3027 m Sea-Bird SBE37 SMP MicroCAT (#5875)
3027 m SonTek Argonaut MD current meter (#D267)
3500 m Sea-Bird SBE37 SMP MicroCAT (#5876)
4028 m Nortek Aquadopp current meter (#1156)
4028 m Sea-Bird SBE37 SMP MicroCAT (#5874)
4028 m SonTek Argonaut MD current meter (#D285)
4500 m Sea-Bird SBE37 SMP MicroCAT (#5873)
4815 m Sea-Bird SBE37 SMP MicroCAT (#5871)

The top part (above 150 m) of the mooring broke free during January 2009 and was recovered in late February 2009. Hence, all instruments above 150 m have shortened records.

The raw data file from Instrument Sea-Bird SBE37 MicroCAT #3861 did not contain any data from the first 8 days of the deployment. The exact reason for this is unknown but could be due to a problem with the deployment setup of the instrument.

Instrument Sea-Bird SBE37 MicroCAT #0483 was flooded and no data are expected.

Instruments SonTek Argonaut MD current meter #D284 and #D267 recorded no good data, hence no data available.

Instrument SonTek Argonaut MD current meter #D285 only recorded data for 6 months and all data were bad. No data are available.

Other Series linked to this Data Activity - 972954 973029 973109 973066 973110 1016116 972966 972978 1016104 973054 1016128 973091 1016097 972991 973005 973078 973017 973030 973042 1016073

Cruise

Cruise Name SJ-08-03 Leg 1
Departure Date 2008-04-04
Arrival Date 2008-04-20
Principal Scientist(s)William E Johns (Rosenstiel School of Marine and Atmospheric Science)
Ship RV Seward Johnson

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 - 972954 972966 972978 972991 973005 973017 973029 973030 973042 973054 973066 973078 973091 973109 973110 973122 973134 973146 973158 973171 973183 973195 973202 973214 973226 973238 973251 973263 973275 973287 973299 1016073 1016097 1016104 1016116 1016128 1196693 1196700

Other Cruises linked to this Fixed Station (with the number of series) - D278 (90) D344 (10) D345 (43) D346 (31) D382 (79) EN517 (11) JC103 (7) KN182_2 (87) KN200-4 (135) OC459-1 (64) RB0602 (42) RB0701 (58) RB0901 (78) RB1009 (24) RB1201 (91) 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