Metadata Report for BODC Series Reference Number 603784

Metadata Summary

Data Description
Data Category Currents -subsurface Eulerian
Instrument Type Acoustic doppler current profiler
Instrument Mounting subsurface mooring
Originating Country United Kingdom
Originator Mr John Howarth
Originating Organization Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Processing Status QC in progress
Project(s) Coastal Observatory
 

Data Identifiers

Originator's Identifier R854/BB2391
BODC Series Reference 603784
 

Time Co-ordinates(UT)
Start Time (yyyy-mm-dd hh:mm) 2002-09-25 19:15
End Time (yyyy-mm-dd hh:mm) 2002-11-13 11:55
Nominal Cycle Interval 600.0 seconds
 

Spatial Co-ordinates

Latitude 53.53320 N ( 53° 32.0' N )
Longitude 3.36320 W ( 3° 21.8' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 0.0 m
Maximum Sensor Depth 21.0 m
Minimum Sensor Height 0.0 m
Maximum Sensor Height 21.0 m
Sea Floor Depth 21.0 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 Sea floor reference - Depth measured as a height above sea floor but converted into a depth relative to the sea surface according to the same datum as used for sea floor depth (applicable to instrument depths not bathymetric depths)
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters
BODC CODE Rank Units Title
HBINAA01 0 Metres Height above bed (ADCP bin) in the water body
AADYAA01 1 Days Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time (time between 00:00 UT and timestamp)
LCEWAP01 2 Centimetres per second Eastward current velocity (Eulerian) in the water body by moored acoustic doppler current profiler (ADCP)
LCNSAP01 2 Centimetres per second Northward current velocity (Eulerian) in the water body by moored acoustic doppler current profiler (ADCP)
LERRAP01 2 Centimetres per second Current velocity error in the water body by moored acoustic doppler current profiler (ADCP)
LRZAAP01 2 Centimetres per second Upward current velocity in the water body by moored acoustic doppler current profiler (ADCP)
 

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

Public domain data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

Narrative Documents

RDI Acoustic Doppler Current Profiler

Acoustic Doppler Current Profilers (ADCPs) use sound waves to determine vertical profiles of currents, and may be deployed fixed to the sea floor, attached to a surface buoy, mounted on the hull of a ship, towed behind a ship or lowered on a cable.

ADCPs transmit sound bursts into the water. Particles carried by the water currents scatter the sound back to the transducer. As echoes return from further ranges from the sensor, the instrument assigns different water depths to the returning signals. Motion of the scattering particles relative to the sound source causes a change in the frequency of the sound (known as Doppler shift). The ADCP measures this change to produce vertical profiles of water velocity at up to 128 depths throughout the water column.

Specifications:
number of depth cells 1 to 128;
size of depth cells 0.12 to 32.00 metres;
velocity range +/- 10 m/s.

Coastal Observatory ADCP data processing

Data Processing at POL

The 600 kHz RDI Workhorse Monitor ADCP was set up to sample every 10 minutes, profiling the water column in 1 m bins. The first bin was 2.7 metres above bed (mab) and there were 28 bins in total.

The data were corrected for a magnetic deviation of 4.5°W and the time stamp for each record was adjusted to the scan time plus half the sampling interval.

Data Processing at BODC

At BODC, the data were converted from ASCII format into BODC QXF format, a subset of NetCDF. This conversion included assigning bin heights above the seabed.

General Data Screening carried out by BODC

BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.

Header information is inspected for:

Documents are written by BODC highlighting irregularities which cannot be resolved.

Data cycles are inspected using time or depth series plots of all parameters. Currents are additionally inspected using vector scatter plots and time series plots of North and East velocity components. These presentations undergo intrinsic and extrinsic screening to detect infeasible values within the data cycles themselves and inconsistencies as seen when comparing characteristics of adjacent data sets displaced with respect to depth, position or time. Values suspected of being of non-oceanographic origin may be tagged with the BODC flag denoting suspect value; the data values will not be altered.

The following types of irregularity, each relying on visual detection in the plot, are amongst those which may be flagged as suspect:

If a large percentage of the data is affected by irregularities then a Problem Report will be written rather than flagging the individual suspect values. Problem Reports are also used to highlight irregularities seen in the graphical data presentations.

Inconsistencies between the characteristics of the data set and those of its neighbours are sought and, where necessary, documented. This covers inconsistencies such as the following:

This intrinsic and extrinsic screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC making are not introduced.

Project Information

Proudman Oceanographic Laboratory Coastal Observatory

The Coastal Observatory was established by Proudman Oceanographic Laboratory as a coastal zone real time observing and monitoring system. The main objective is to understand a coastal sea's response both to natural forcing and to the consequences of human activity. Near real-time measurements will be integrated with coupled models into a pre-operational coastal prediction system whose results will be displayed on the World Wide Web.

The Observatory is expected to grow and evolve as resources and technology allow, all the while building up long time series. A site selection pilot study was carried out in September 2001 and the Observatory became operational in August 2002.

The site is located in Liverpool Bay and is subject to typical coastal sea processes, with strong tides, occasional large storm surges and waves, freshwater input, stable and unstable stratification, high suspended sediment concentration and biogeochemical interaction. Measurements and monitoring will focus on the impacts of storms, variations in river discharge (especially the Mersey), seasonality and blooms in Liverpool Bay.

A variety of methods will be used to obtain measurements, including:

  1. Moored instruments for in situ time series of currents, temperature and salinity profiles, and surface waves and meteorology. It is hoped that turbidity and chlorophyll measurements will be made at another site as the Observatory progresses;
  2. The Cefas Smartbuoy for surface properties such as nutrients and chlorophyll, starting late 2002;
  3. R.V. Prince Madog to carry out spatial surveys and service moorings;
  4. Instrumented ferries for near surface temperature, salinity, turbidity, chlorophyll and nutrients. The first route will be Liverpool to Douglas, Isle of Man, starting late 2002;
  5. Drifters for surface currents and properties such as temperature and salinity, starting in 2004;
  6. Tide gauges, with sensors for meteorology, waves, temperature and salinity, where appropriate;
  7. Meteorological data from Bidston Observatory, HF radar and tide gauge sites;
  8. Shore-based HF radar measuring waves and surface currents out to a range of 50 km, starting in 2003;
  9. Satellite data, with infrared for sea surface temperature and visible for chlorophyll and suspended sediment.

The partners currently involved with the project are listed below:

A summary of Coastal Observatory cruises to date on R.V. Prince Madog is given in the table below:

Year No. of cruises Work summary
2001 1 Site selection and pilot study. 95 CTD casts.
2002 4 POL moorings deployed and serviced
Cefas Waverider and SmartBuoy deployed and serviced
103 CTD casts
2003 10 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
341 CTD/LISST casts
2004 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
347 CTD/LISST casts
2005 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
268 CTD/LISST casts
2006 11 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
508 CTD/LISST casts
2007 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
471 CTD/LISST casts
2008 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
260 CTD/LISST casts
2009 7 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
213 CTD/LISST casts
2010 8 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
268 CTD/LISST casts
2011 6 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
307 CTD/LISST casts to date, ongoing

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2002-09-25
End Date (yyyy-mm-dd) 2002-11-13
Organization Undertaking ActivityProudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPOLRIG#854
Platform Categorysubsurface mooring

Proudman Oceanographic Laboratory Rig#854

This rig was deployed as part of the Liverpool Bay Coastal Observatory during R.V. Prince Madog cruise PD024_02.

The instruments were mounted on POL frame D6, which was deployed onto the sea floor. The frame was fitted with two Benthos releases (5A and 8A) and a spooler for recovery of the ballast weight.

Recovery of the rig took place during R.V. Prince Madog cruise PD31_02. The acoustic releases were fired but the frame did not surface as expected. Sweeping for the rig was commenced, using a loop of wire the width of the stern. After the third attempt, the frame and ballast weight were snagged and came to the surface under their own buoyancy.

It was noted that the frame and instruments were covered in a furry green algal growth.

Instrument Meter Height Parameters Measured
ADCP 2391 0.5m Velocity profile
Transmissometer ST557 0.5m Temperature, conductivity, pressure, beam attenuation
Pressure recorder 444 0.5m Temperature, pressure
Sea-Bird MicroCAT 2506 0.5m Temperature, conductivity, pressure

Other Series linked to this Data Activity - 646249 636845 636808

Fixed Station Information

Fixed Station Information

Station NameCOA
CategoryOffshore area
Latitude53° 31.51' N
Longitude3° 23.00' W
Water depth below MSL26.0 m

Liverpool Bay Coastal Observatory Mooring Site A (COA/Site 1/Site 9)

This station is the main mooring site for the Proudman Oceanographic Laboratory (POL) Liverpool Bay Coastal Observatory and was first occupied in 2002. It is also known both as Coastal Observatory Site 1 and Site 9. POL perform two main types of activities at this station: they deploy moorings; and in addition, they take CTD profiles during each site visit. The station lies within a box of mean water depth 22.5 m with the following co-ordinates:

Box Corner Latitude (+ve North) Longitude (+ve East)
North-west corner 53.54097 -3.42958
South-east corner 53.50945 -3.33714

The position of this station relative to the other POL Coastal Observatory sites can be seen from the figure below.

BODC image

Mooring Deployment History

2011

Rig Type Typical Instruments Rig IDs Comment
Frame ADCP, CTD, OBS, OXY 1117 for January cruise. Other frame IDs not available at this time. January - September
SmartBuoy CTD x 2, AC-S, CT x 2, FL x 3, OBS x 2, PAR x 2, WMS, NAS, OXY, T x 2 1116 for January cruise. Other frame IDs not available at this time. January - September
SparBuoy AC-S, FL, CTD x 2, T Frame ID not available at this time. September

2010

Rig Type Typical Instruments Rig IDs Comment
Frame ADCP, CTD, ADV, OBS 1086, 1090, 1094, 1098, 1102, 1106, 1109 January - December
SmartBuoy CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T 1085, 1089, 1093, 1097, 1101, 1105, 1108, 1112 January - December

2009

Rig Type Typical Instruments Rig IDs Comment
Frame ADCP, CTD, ADV, OBS 1055, 1062, 1067, 1071, 1074, 1078, 1082 January - December
SmartBuoy CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T 1054, 1061, 1066, 1070, 1073, 1077, 1081 January - December

2008

Rig Type Typical Instruments Rig IDs Comment
Frame ADCP, CTD, ADV, OBS 1024, 1028, 1032, 1036, 1041, 1044, 1047, 1051 January - December
SmartBuoy CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T LB1_047/1023, LB1_048/1027, LB1_049/1031, LB1_050/1035, 1040, 1043, LB1_053/1050 January - December

2007

Rig Type Typical Instruments Rig IDs Comment
Frame ADCP, CTD, ADV, OBS 990, 997, 1001, 1005, 1010, 1014, 1017, 1021 January - December
SmartBuoy CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T LB1_039/989, LB1_040/996, LB1_041/1000, LB1_042/1004, LB1_043/1009, LB1_044/1013, LB1_045/1016, LB1_046/1020 January - December

2006

Rig Type Typical Instruments Rig IDs Comment
Frame ADCP, CTD, ADV, OBS 951, 962, 966, 970, 974, 978, 982, 986 January - December
SmartBuoy CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD 958, 961, 965, 969, 973, 977, LB1_037/981, LB1_038/985 January - December

2005

Rig Type Typical Instruments Rig IDs Comment
Frame ADCP, CT 913, 914, 921, 925, 929, 933, 938, 942, 945, 949 January - December
SmartBuoy CT, FL, OBS, PAR, WMS, NAS, OXY 912, 920, 924, 928, 932, 937, LB1_028/941, LB1_029/944, LB1_030/948 January - December
Frame with telemetry buoy ADCP 914 March - April

2004

Rig Type Typical Instruments Rig IDs Comment
Frame BPR, ADCP, TR, CT 890, 892, 893, 896, 898, 900, 902, 904, 907, 908, 910, 911 January - December
SmartBuoy CT, FL, OBS, PAR, WMS, NAS 889, 891, 895, 897, 899, 901, 903, 906, 909 January - December
Frame with telemetry buoy ADCP 893, 908, 911 April - May, October - December

2003

Rig Type Instruments Rig IDs Comment
Frame BPR, ADCP, TR, CT 861, 864, 866, 869, 872, 878, 880, 883, 885, 887, 888 January - December
SmartBuoy CT, FL, OBS, PAR, WMS, NAS 863, 865, 867, 870, 871, 877, 879, 882, 884, 886 January - December

2002

Rig Type Instruments Rig IDs Comment
Frame BPR, ADCP, TR, CT 851, 854, 856, 858 August - December
Line mooring CT x 3 853, 855 August - November
SmartBuoy CT, FL, OBS, PAR, WMS, NAS 857, 860 November - December

2001

Rig Type Instruments Rig IDs Comment
Frame ADCP, OBS 838, 839, 840, 841, 843, 844, 845, 846, 848, 849 September

CTD Sampling History

Year Number of Cruises Total Casts per year
2011 6 116 including a 46 cast tidal cycle from 2011-04-18 to 2011-04-19 and a 51 cast tidal cycle station from 2011-07-27 to 2011-07-28
2010 7 69 including a 52 cast tidal cycle station from 2010-04-28 to 2010-04-29
2009 7 21
2008 9 75 including a 54 cast tidal cycle station from 2008-05-13 to 2008-05-14
2007 8 71 including a 51 cast tidal cycle station from 2007-05-15 to 2007-05-16
2006 9 72 including a 53 cast tidal cycle station from 2006-05-09 to 2006-05-10
2005 9 41 including a 22 cast tidal cycle station from 2005-04-05 to 2005-04-06
2004 9 77 including a 54 cast tidal cycle station from 2004-05-11 to 2004-05-12
2003 10 28
2002 4 13

The CTD instrument package for these cruises was a Sea-Bird 911plus, with beam transmissometer, fluorometer, LICOR PAR sensor, LISST-25, and oxygen sensor.

Key

AC-S = Absorption and attenuation spectrophotometer
ADCP = Acoustic Doppler Current Profiler
ADV = Acoustic Doppler Velocimeter
BD = Bacterial degradation experiment
BPR = Bottom Pressure Recorder
CT = Conductivity and temperature logger
CTD = Conductivity, temperature, depth sensor
FL = Fluorometer
NAS = in-situ nutrient analyser
OBS = Optical Backscatter Turbidity meter
OXY = Oxygen sensor
PAR = PAR sensor
T = Temperature logger
TR = Transmissometer
WMS = Automatic water sampler

Other Series linked to this Fixed Station - 592914 592926 592938 592951 593235 636790 636808 636821 636833 636845 636857 646004 646016 646028 646041 646053 646065 646077 646089 646090 646108 646121 646133 646145 646157 646169 646170 646182 646194 646201 646213 646225 646237 646249 646250 646262 646274 646286 646298 646305 646317 646329 646330 646342 646354 646366 646378 646968 646981 646993 647007 647019 647020 647032 647044 647056 647068 647081 647093 647100 647112 662667 662679 662680 662692 662711 662723 662735 662747 662759 664152 664164 664176 664188 664207 664219 664220 664232 664244 664256 664268 664281 664293 664300 664312 664324 664336 664348 680023 680035 680047 680059 680060 680072 680084 680096 680103 680115 680127 680139 680140 680152 680164 680176 680188 680207 680219 680220 680232 680244 680256 695937 695949 695950 695974 696271 696283 696295 696302 696326 696338 696375 698787 698799 698831 698843 698879 698892 698972 700345 700357 700369 700401 700413 700425 700462 700474 700486 700498 700505 700517 700529 700530 700542 700554 700566 700578 700591 700609 700610 700622 700634 700646 701650 701662 701674 701705 701730 701742 701754 701846 701895 701902 701926 701938 747008 747021 747033 747045 747057 747125 747137 747149 747150 747162 747230 747242 747254 747266 747278 747291 747309 747310 747322 747334 747346 747358 747371 747383 747395 747402 747414 747426 747438 747451 747463 747475 747487 747499 747506 747518 747531 747543 747555 747567 752926 752938 752951 752963 752975 752999 753002 753026 753038 753075 753099 753118 753143 753167 753180 753432 753444 753456 753468 767833 767869 767882 767901 770411 770435 770459 770460 770496 770503 770515 770527 770552 770564 772270 772294 772313 772337 772349 772374 772386 772405 772430 772442 805455 808730 838288 838319 838332 838356 838368 857888 857907 857932 861980 861992 862006 862018 862031 862043 862055 862067 862079 862080 862196 862203 862215 862227 862239 862240 862252 862264 862276 862288 862400 862412 862424 862436 862448 862461 862473 862485 862497 862504 862621 862633 862645 862657 862669 862670 862682 862694 862701 862713 862725 862737 862749 862750 862762 862774 862786 862798 862805 862817 862829 862830 862842 862854 862866 862878 862891 862909 862910 862922 937502 937680 939220 939256 939268 939281 939293 941390 941408 941433 941457 941469 941482 941494 941501 941513 941525 941537 941549 941550 941562 941574 941586 941598 941605 941617 941629 941630 941642 941654 941666 941678 941691 941709 941710 941722 941734 941746 941758 941771 941783 941795 941802 941814 941826 941838 941851 941863 941875 941887 941899 941906 941918 941931 941943 941955 941967 941979 941980 941992 942006 942018 942135 942725 942737 942830 943175 943187 943280 943568 943581 943697 945526 945538 945643 946345 946370 946382 946401 946498 946505 946671 946775 946867 946879 947103 947115 947244 947256 947441 947453 947465 947477 947489 947490 947508 947521 947533 947545 947557 947569 947570 947582 947594 947601 947613 947625 947637 947649 947650 947662 947674 947686 947698 947705 947717 947729 947730 947742 947754 947766 947778 947791 947809 947810 947822 947834 947846 947858 947871 947883 947895 947902 947914 947926 947938 947951 947963 947975 947987 947999 948002 948118 948500 948745 949238 949251 949367 949668 949681 949889 949890 950092 950111 950203 950461 950589 951218 951231 951488 952836 952861 952885 952904 953495 953502 953784 979037 979050 979222 1003634 1003646 1012858 1013143 1022877 1022889 1022890 1022933 1022945 1022957 1022982 1022994 1023008 1023125 1023402 1023414 1023438 1024097 1024104 1024362 1024509 1024510 1024522 1024583 1024595 1024602 1024663 1024675 1024687 1024743 1024755 1024767 1024779 1024780 1024792 1024811 1024823 1024835 1024847 1024859 1024860 1030299 1030306 1030367 1030379 1030540 1038290 1038308 1048388 1048407 1048419 1048420 1048456 1048468 1075350 1075362 1075374 1075386 1075398 1075405 1075417 1075429 1075430 1075442 1075454 1075466 1075478 1075491 1075509 1075767 1075779 1075780 1075792 1075811 1075823 1075835 1075847 1075859 1075860 1075872 1075884 1075896 1075903 1075915 1075927 1075939 1075940 1075952 1075964 1075976 1075988 1076003 1076015 1076027 1076039 1076040 1076052 1076064 1076144 1076156 1076168 1076181 1076193 1076200 1076212 1076224 1076236 1076248 1076261 1076273 1076285 1076297 1076304 1076316 1076328 1076341 1076353 1076365 1076377 1076389 1076390 1076408 1076421 1076433 1076445 1076457 1076469 1076470 1076482 1076494 1076501 1076513 1076525 1076537 1076549 1076550 1076562 1076574 1076586 1076598 1076605 1076617 1076666 1076678 1076691 1076709 1076710 1076722 1076734 1076746 1076758 1076771 1076783 1076795 1076802 1076814 1076826 1076838 1076851 1076863 1082162 1082174 1082229 1082230 1082242 1082254 1082291 1082309 1082310 1082322 1082334 1082346 1082358 1082371 1082383 1082395 1082402 1082414 1082426 1082438 1082451 1082463 1082475 1082487 1082499 1082506 1082518 1082531 1082543 1082555 1082567 1090383 1090395 1090715 1090739 1090740 1090868 1112036 1112048 1112313 1113906 1113918 1114184 1116873 1116885 1116897 1116904 1116916 1116928 1116941 1116977 1116989 1116990 1117004 1117016 1117028 1117041 1117053 1117065 1117077 1117089 1117090 1117108 1117121 1117133 1117145 1117201 1117213 1117225 1117237 1117249 1117250 1117262 1117274 1117286 1117298 1117305 1117317 1117329 1117330 1117342 1117354 1117366 1117378 1117391 1117409 1117410 1117422 1117434 1117446 1117711 1118333 1118345 1118357 1118437 1118486 1118498 1118658

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