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Metadata Report for BODC Series Reference Number 1722295


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI 300kHz Workhorse Monitor direct-reading ADCP  current profilers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Penny Holliday
Originating Organization National Oceanography Centre, Southampton
Processing Status QC in progress
Online delivery of data Download not available
Project(s) -
 

Data Identifiers

Originator's Identifier LADCP_047
BODC Series Reference 1722295
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2015-06-10 13:23
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 5.0 decibars
 

Spatial Co-ordinates

Latitude 57.56742 N ( 57° 34.0' N )
Longitude 13.33212 W ( 13° 19.9' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 5.0 m
Maximum Sensor or Sampling Depth 170.0 m
Minimum Sensor or Sampling Height 13.0 m
Maximum Sensor or Sampling Height 178.0 m
Sea Floor Depth 183.0 m
Sea Floor Depth Source CTDDATA
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum Approximate - Depth is only approximate
 

Parameters

No Parameters for BODC Reference Number = 1722295

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 Quality Report

All casts were processed, although it was noted that casts shallower than 100-200 m often seemed to have problems, usually characterised as giving a profile that was significantly deeper than the true water depth. It is assumed this was due to confusing reflections at the seabed, and recommend that those profiles not be used (Casts 35, 37, 46, 47, 68-75, 79-81, 83). For more information see the cruise report page 35.


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

Instrument Description

The LADCP data were collected using the instrumentation detailed below:

Sensor Model Serial Number Calibration (UT) Comments
LADCP Teledyne RDI high-power Workhorse 300kHz 15288 - LDEO unit, downward looking

One Teledyne RDI Workhorse 300kHz ADCP was mounted on the Sea-Bird 9 11 plus CTD frame pointing downward (downlooker).

Teledyne RDI's Workhorse Monitor ADCP

The Workhorse Monitor acoustic doppler current profler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented four beam signal (300, 600 or 1200 kHz) and a standard depth rating of 200m or 600m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

BODC Processing

LDEO processed data were provided by the originator in Matlab and ASCII formats. The LDEO processed data in ASCII format were converted into BODC internal format after discussion with the originator. All data provided were from the downward looking RDI 300 kHz Workhorse ADCP which was in operation at the time. The following table shows how the variables within the ASCII files were mapped to appropriate BODC parameter codes:

Originator's Parameter Name Units Description BODC Parameter Code Units Comments
z m Depth of LADCP bin ADEPZZ01 m -
u m s-1 Eastward velocity LCEWLW01 cm s-1 Units converted from m s-1 to cm s-1 by multiplying by 100.
v m s-1 Northward velocity LCNSLW01 cm s-1 Units converted from m s-1 to cm s-1 by multiplying by 100.
ev m s-1 Uncertainty estimates of LADCP velocity profile ERRVLDCP cm s-1 Units converted from m s-1 to cm s-1 by multiplying by 100.

All reformatted data were visualised using the in-house Edserplo software. Suspect and missing data were marked by adding an appropriate quality control flag.

Note that the more complex LDEO processed data are available on request in Matlab format as well as the unprocessed raw LADCP files.

Originator's Data Processing

Sampling Strategy

A total of 84 LADCP profiles were collected at all CTD stations in order to derive full-depth profiles of ocean velocity, as well as profiles of finestructure vertical shear.

Data processing

Preliminary shipboard processing of the LADCP data was carried out with the LDEO IX LADCP processing software using averaged one Hz ascii CTD data in order to correct the LADCP data for depth and sound speed.

Please refer to Thurnherr (2014) and cruise report for a more detailed processing methodology. However, please be aware that this processing guide is for software versions IX.7 to IX.10 only, and changes have been made between versions which have the potential for significantly changing the solutions.

References

Thurnherr, A. M., 2014. How To Process LADCP Data With the LDEO Software, Versions IX.7 - IX.10.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name DY031
Departure Date 2015-05-29
Arrival Date 2015-06-17
Principal Scientist(s)N Penny Holliday (National Oceanography Centre, Southampton)
Ship RRS Discovery

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameEllett Line/Extended Ellett Line Station B
CategoryOffshore location
Latitude57° 34.02' N
Longitude13° 19.98' W
Water depth below MSL210.0 m

Ellett Line/Extended Ellett Line: Station B

Station B is one of the fixed CTD stations, which together form The Extended Ellett Line. The line lies between Iceland and the Sound of Mull (Scotland) crossing the Iceland Basin and Rockall Trough via the outcrop of Rockall. As part of this initiative, CTD dips, together with associated discrete sampling of the water column, have typically been carried out annually at this station since September 1996.

Prior to September 1996, Station B was part of a shorter repeated survey section, consisting of 35 fixed stations, known as The Ellett Line (originally termed the Anton Dohrn Seamount Section). This line incorporated those stations across the Rockall Trough and Scottish shelf between Rockall and the Sound of Mull and was visited at regular intervals (usually at least once a year) between 1975 and January 1996.

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: Ellett Line/Extended Ellett Line Station B

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
90281CTD or STD cast1975-11-09 21:30:0057.565 N, 13.335 WRRS Challenger CH14A/75
90416CTD or STD cast1976-04-01 20:42:0057.5666 N, 13.3333 WRRS Challenger CH5A/76
91327CTD or STD cast1976-05-23 08:55:0057.5583 N, 13.33 WRRS Challenger CH8/76
92109CTD or STD cast1977-04-16 18:56:0057.5666 N, 13.3533 WRRS Challenger CH6B/77
94097CTD or STD cast1977-07-23 09:34:0057.5633 N, 13.33 WRRS Challenger CH11/77
88842CTD or STD cast1977-08-23 01:02:0057.5533 N, 13.32 WRRS Challenger CH13/77
92306CTD or STD cast1978-02-04 21:24:0057.5683 N, 13.3233 WRRS Challenger CH2/78
92392CTD or STD cast1978-02-06 08:10:0057.5683 N, 13.3216 WRRS Challenger CH2/78
94398CTD or STD cast1978-04-15 20:55:0057.5666 N, 13.315 WRRS Challenger CH6/78
95181CTD or STD cast1978-06-05 02:10:0057.5633 N, 13.3266 WRRS Challenger CH9/78
185974CTD or STD cast1978-08-09 09:36:0057.5666 N, 13.3283 WRRS Challenger CH11B/78
187446CTD or STD cast1980-03-01 18:33:0057.565 N, 13.335 WRRS Challenger CH4/80
188818CTD or STD cast1980-05-03 12:08:0057.5666 N, 13.32 WRRS Challenger CH7/80
188265CTD or STD cast1981-04-19 19:30:0057.5683 N, 13.3316 WRRS Challenger CH6B/81
189373CTD or STD cast1982-05-08 18:30:0057.5666 N, 13.335 WRRS Challenger CH7B/82
96891CTD or STD cast1983-08-17 12:50:0057.565 N, 13.3283 WRRS Challenger CH11/83
313401CTD or STD cast1984-06-29 10:27:0057.5667 N, 13.3317 WRRS Challenger CH2/84
257403CTD or STD cast1984-11-21 04:23:0057.5683 N, 13.33 WRRS Challenger CH10/84
254073CTD or STD cast1985-05-09 22:33:0057.5683 N, 13.3333 WRRS Challenger CH4/85
261383CTD or STD cast1985-08-21 22:56:0057.57 N, 13.3316 WRRS Challenger CH8/85
250397CTD or STD cast1987-04-28 08:09:0057.5666 N, 13.3316 WRRS Challenger CH14
265532CTD or STD cast1989-01-26 02:30:0057.5666 N, 13.35 WRRS Discovery D180
266025CTD or STD cast1989-05-07 09:39:0057.5666 N, 13.3333 WRV Lough Foyle LF1/89
317819CTD or STD cast1989-08-06 11:49:0057.5667 N, 13.335 WRV Lough Foyle LF2/89
316994CTD or STD cast1989-11-27 10:20:0057.5667 N, 13.3333 WRRS Charles Darwin CD44
314902CTD or STD cast1990-06-27 01:27:0057.5617 N, 13.325 WRRS Challenger CH67A
259618CTD or STD cast1990-09-01 04:22:0057.5666 N, 13.3333 WRRS Challenger CH71A
382689CTD or STD cast1991-02-28 09:25:0057.5667 N, 13.3317 WRRS Challenger CH75B
316380CTD or STD cast1991-07-04 01:20:0057.5683 N, 13.335 WRRS Challenger CH81
386654CTD or STD cast1992-09-28 18:26:0057.5667 N, 13.33 WRRS Challenger CH97
385558CTD or STD cast1993-05-14 20:54:0057.5667 N, 13.335 WRRS Challenger CH103
387701CTD or STD cast1993-09-05 08:45:0057.5703 N, 13.3218 WRRS Challenger CH105
389166CTD or STD cast1994-05-02 02:31:0057.5682 N, 13.34 WRRS Challenger CH112
391005CTD or STD cast1994-08-19 12:29:0057.5668 N, 13.3342 WRRS Challenger CH114
435237CTD or STD cast1995-04-27 13:53:0057.5667 N, 13.3333 WRRS Charles Darwin CD92B
390604CTD or STD cast1995-08-01 16:28:0057.5667 N, 13.3333 WRRS Challenger CH120
434210CTD or STD cast1996-01-14 21:03:0057.5667 N, 13.3333 WRRS Challenger CH124
1014748CTD or STD cast1996-10-02 22:42:0057.5685 N, 13.3375 WRRS Discovery D223A
1850248Water sample data1996-10-02 22:57:0057.56848 N, 13.33756 WRRS Discovery D223A
1076906CTD or STD cast1999-05-30 12:54:0057.5625 N, 13.32967 WNot applicable
1070818CTD or STD cast1999-09-13 23:44:0057.56467 N, 13.32967 WRRS Discovery D242
1252156Water sample data1999-09-13 23:50:0057.56467 N, 13.32967 WRRS Discovery D242
559032CTD or STD cast2000-05-17 19:34:0057.565 N, 13.325 WFRV Scotia 0700S
676952CTD or STD cast2001-05-22 02:05:0057.56733 N, 13.33283 WRRS Discovery D253
626875CTD or STD cast2003-04-19 06:17:0057.566 N, 13.3357 WFRV Scotia 0703S
844872CTD or STD cast2003-07-20 22:45:0057.56795 N, 13.33965 WFS Poseidon PO300_2
667229CTD or STD cast2004-07-15 04:01:0057.56833 N, 13.33517 WFS Poseidon PO314
896574CTD or STD cast2005-10-12 18:31:0057.56726 N, 13.3329 WRRS Charles Darwin CD176
776479CTD or STD cast2006-10-22 07:51:0157.5695 N, 13.33067 WRRS Discovery D312
847384CTD or STD cast2007-08-28 17:17:5457.5676 N, 13.33293 WRRS Discovery D321B
880744CTD or STD cast2008-05-21 06:27:0057.56767 N, 13.33167 WFRV Scotia 0508S
1616774Water sample data2008-05-21 06:27:0057.56767 N, 13.33167 WFRV Scotia 0508S
954197CTD or STD cast2009-06-16 08:49:5057.56775 N, 13.33554 WRRS Discovery D340A
1052664CTD or STD cast2010-05-18 21:11:1057.564 N, 13.33783 WRRS Discovery D351
1929874Currents -subsurface Eulerian2010-05-18 21:11:4857.5653 N, 13.3363 WRRS Discovery D351
1896688Water sample data2010-05-18 21:29:0057.56373 N, 13.33837 WRRS Discovery D351
1195677CTD or STD cast2011-05-29 22:45:3857.56583 N, 13.33483 WRRS Discovery D365
1203624CTD or STD cast2012-08-05 15:24:0057.5668 N, 13.33241 WRRS Discovery D379
1220314CTD or STD cast2013-05-18 14:49:2257.5667 N, 13.3333 WRRS James Cook JC086
1371075CTD or STD cast2014-07-14 16:24:2657.5669 N, 13.3329 WRRS James Clark Ross JR20140531 (JR302)
1723213CTD or STD cast2015-06-10 13:22:5857.5674 N, 13.3321 WRRS Discovery DY031
1879151Water sample data2015-06-10 13:37:0057.56741 N, 13.33211 WRRS Discovery DY031
1764488CTD or STD cast2016-06-15 17:49:1157.5667 N, 13.3332 WRRS Discovery DY052
1765627Currents -subsurface Eulerian2016-06-15 17:49:3357.56673 N, 13.33322 WRRS Discovery DY052
1874816Water sample data2016-06-15 18:00:0057.56673 N, 13.33322 WRRS Discovery DY052