Metadata Report for BODC Series Reference Number 1207729


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI Ocean Surveyor 75kHz vessel-mounted ADCP  current profilers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Miss Charlotte Marcinko
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Project(s) Oceans 2025
Oceans 2025 Theme 10
Oceans 2025 Theme 10 SO4
 

Data Identifiers

Originator's Identifier SUR35107
BODC Series Reference 1207729
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2010-05-17 11:32
End Time (yyyy-mm-dd hh:mm) 2010-05-18 11:34
Nominal Cycle Interval 120.0 seconds
 

Spatial Co-ordinates

Start Latitude 59.20167 N ( 59° 12.1' N )
End Latitude 58.09850 N ( 58° 5.9' N )
Start Longitude 17.88767 W ( 17° 53.3' W )
End Longitude 14.94433 W ( 14° 56.7' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 17.0 m
Maximum Sensor Depth 809.0 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Sensor fixed, measurements made at fixed depths - The sensor is at a fixed depth, but measurements are made remotely from the sensor over a range of depths (e.g. ADCP measurements)
Sensor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum -
 

Parameters

BODC CODE Rank Units Short Title Title
DBINAA01 0 Metres BinDep Depth below sea surface (ADCP bin)
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
ALATGP01 1 Degrees Lat_GPS Latitude north (WGS84) by unspecified GPS system
ALONGP01 1 Degrees Lon_GPS Longitude east (WGS84) by unspecified GPS system
APEWGP01 1 Centimetres per second PlatformVelE_GPS Eastward velocity (over ground) of measurement platform by unspecified GPS system
APNSGP01 1 Centimetres per second PlatformVelN_GPS Northward velocity (over ground) of measurement platform by unspecified GPS system
ASAMSP00 2 Decibels SB_ADCP_SA Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 1
ASAMSP02 2 Decibels SB_ADCP_SA2 Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 2
ASAMSP03 2 Decibels SB_ADCP_SA3 Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 3
ASAMSP04 2 Decibels SB_ADCP_SA4 Signal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 4
LCEWAS01 2 Centimetres per second CurrVelE_ADCP Eastward current velocity (Eulerian) in the water body by shipborne acoustic doppler current profiler (ADCP)
LCNSAS01 2 Centimetres per second CurrVelN_ADCP Northward current velocity (Eulerian) in the water body by shipborne acoustic doppler current profiler (ADCP)
LERRAS01 2 Centimetres per second ADCPER Current velocity error in the water body by shipborne acoustic doppler current profiler (ADCP)
LREWAS01 2 Centimetres per second RelCurrVelE_ADCP Eastward current velocity (relative to moving platform) in the water body by shipborne acoustic doppler current profiler (ADCP)
LRNSAS01 2 Centimetres per second RelCurrVelN_ADCP Northward current velocity (relative to moving platform) in the water body by shipborne acoustic doppler current profiler (ADCP)
LRZAAS01 2 Centimetres per second ADCPVC Upward current velocity in the water body by shipborne 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

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

RD Instruments- Ocean Surveyor 75kHz Vessel mounted ADCP.

Long-Range Mode
Vertical Resolution Cell Size 3 Max. Range (m) 1 Precision (cm/s) 2
8m 520 - 650 30
16m 560 - 700 17
High-Precision Mode
Vertical Resolution Cell Size 3 Max. Range (m) 1 Precision (cm/s) 2
8m 310 - 430 12
16m 350 - 450 9

1 Ranges at 1 to 5 knots ship speed are typical and vary with situation.
2 Single-ping standard deviation.
3 User's choice of depth cell size is not limited to the typical values specified.

Profile Parameters

Bottom Track

Maximum altitude (precision <2cm/s): 950m

Echo Intensity Profile

Dynamic range: 80dB
Precision: ±1.5dB

Transducer and Hardware

Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W

Standard Sensors

Temperature (mounted on transducer)

Environmental

Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*

*later instruments have greater range.

Web Page

Further details can be found on the manufacturer's website or in the specification sheet

D351 Vessel Mounted ADCP Data Document

The following contains extracts from the D351 cruise report.

Originator's Protocol for Data Acquisition and Analysis

The RRS Discovery D351 funded by NERC was part of the Oceans 2025 programme. The programme ran for five years with the aim of improving our understanding of how our seas behave and how they are changing, and what that might mean not just for our oceans, but for society.

D351 departed on 11 May 2010 from the port of Reykjavík, Iceland and returned on the 28 May 2010 to the port of Govan, United Kingdom.

Sample collection

The RRS Discovery D351 was equipped with two hull mounted Ocean Surveyor broadband ADCPs. An RDI broadband 150 kHz ADCP is mounted in the hull 1.75 m to port of the keel, 33 m aft of the bow at the waterline, at an approximate depth of 5.3 m. A 75 kHz ADCP is also mounted in the hull, in a second well 4.15 m forward and 2.5 m to starboard of the 150 kHz well.

The RDI Ocean Surveyor 150 kHz Phased Array VMADCP was configured to sample over 120 second intervals with 96 bins of 4 m depth and a blank beyond transmit of distance of 4 m. The instrument is a broad-band phased array ADCP with 153.6 kHz frequency and a 30° beam angle.

The RDI Ocean Surveyor 75 kHz Phased Array VMADCP was configured to sample over 120 second intervals with 100 bins of 8 m depth and a blank beyond transmit of distance of 8 m. The instrument is a broad-band phased array ADCP with 76.8 kHz frequency and a 30° beam angle.

Data Processing Navigation

The ship's primary position instrument was the GPS Trimble 4000 system. The GPS 4000 system has sufficient precision to enable the calculation of ship's velocities to better than 1 cms -1 , and therefore below the instrumental limits (~ 1 cms - 1 ) of the RDI ADCP systems.

Navigation and gyro data were transferred daily from the RVS format file streams to pstar navigation files.

Data Processing VMADCP

Data were processed using the following scripts:

Calibration

Calibration was achieved by using bottom tracking data made available after departure from Reykjavík across the Icelandic continental shelf. Using long, straight and steady speed sections of standard 2 minute ensemble profiles over reasonably constant depths the following calibrations for misalignment angle, ø, and necessary amplification (tilt), A, were derived:

150 kHz ø A
Mean 1.552749952 1.000666704
SD 0.580535294 0.006883268
75 kHz ø A
Mean 2.845586341 1.002266493
SD 0.575752298 0.009364685

References

Read, J. F. (2010). 'The Extended Ellett Line 2010'. Cruise Report No. 50 National Oceanography Centre, Southampton.

Processing by BODC of RRS Discovery Vessel Mounted ADCP data

The data arrived at BODC in daily PStar files representing the data collected from the vessel mounted ADCP during cruise D351. The data were reformatted to BODC's internal NetCDF format. The following table shows the mapping of variables within the PStar file to appropriate BODC parameter codes:

Originator's Variable Originator's Units Description BODC Parameter Code BODC Units Comment
time seconds - - - NOT TRANSFERRING
bindepth meters Depth below sea surface (ADCP bin) DBINAA01 meters -
evelcal cm/s Eastward current velocity (relative to moving platform) in the water body by shipborne acoustic doppler current profiler (ADCP) LREWAS01 cm/s Calibrated eastward current velocity
nvelcal cm/s Northward current velocity (relative to moving platform) in the water body by shipborne acoustic doppler current profiler (ADCP) LRNSAS01 cm/s Calibrated northward current velocity
velvert cm/s Upward current velocity in the water body by shipborne acoustic doppler current profiler (ADCP) LRZAAS01 cm/s -
velerr cm/s Current velocity error in the water body by shipborne acoustic doppler current profiler (ADCP) LERRAS01 cm/s -
intense1 db Signal return amplitude from the water body by shipborne acoustic doppler current profile (ADCP) beam 1 ASAMSP00 db -
intense2 db Signal return amplitude from the water body by shipborne acoustic doppler current profile (ADCP) beam 2 ASAMSP02 db -
intense3 db Signal return amplitude from the water body by shipborne acoustic doppler current profile (ADCP) beam 3 ASAMSP03 db -
intense4 db Signal return amplitude from the water body by shipborne acoustic doppler current profile (ADCP) beam 4 ASAMSP04 db -
good3bm % - - - NOT TRANSFERRING
verr % - - - NOT TRANSFERRING
2+bmbad % - - - NOT TRANSFERRING
good4bm % - - - NOT TRANSFERRING
ve cm/s Eastward velocity (over ground) of measurement platform by unspecified GPS system APEWGP01 cm/s Ship's eastward velocity
vn cm/s Northward velocity (over ground) of measurement platform by unspecified GPS system APNSGP01 cm/s Ship's northward velocity
absve cm/s Eastward current velocity (Eulerian) in the water body by shipborne acoustic doppler current profiler (ADCP) LCEWAS01 cm/s -
absvn cm/s Northward current velocity (Eulerian) in the water body by shipborne acoustic doppler current profiler (ADCP) LCNSAS01 db -
lat degrees Latitude north (WGS84) by unspecified GPS system ALATGP01 degrees Latitude north from Bestnavdata stream
lon degrees Longitude east (WGS84) by unspecified GPS system ALONGP01 degrees Longitude east from Bestnavdata stream
distrun - - - - NOT TRANSFERRING (can be requested from underway data)

The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.

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

Oceans 2025 - The NERC Marine Centres' Strategic Research Programme 2007-2012

Who funds the programme?

The Natural Environment Research Council (NERC) funds the Oceans 2025 programme, which was originally planned in the context of NERC's 2002-2007 strategy and later realigned to NERC's subsequent strategy (Next Generation Science for Planet Earth; NERC 2007).

Who is involved in the programme?

The Oceans 2025 programme was designed by and is to be implemented through seven leading UK marine centres. The marine centres work together in coordination and are also supported by cooperation and input from government bodies, universities and other partners. The seven marine centres are:

Oceans2025 provides funding to three national marine facilities, which provide services to the wider UK marine community, in addition to the Oceans 2025 community. These facilities are:

The NERC-run Strategic Ocean Funding Initiative (SOFI) provides additional support to the programme by funding additional research projects and studentships that closely complement the Oceans 2025 programme, primarily through universities.

What is the programme about?

Oceans 2025 sets out to address some key challenges that face the UK as a result of a changing marine environment. The research funded through the programme sets out to increase understanding of the size, nature and impacts of these changes, with the aim to:

In order to address these aims there are nine science themes supported by the Oceans 2025 programme:

In the original programme proposal there was a theme on health and human impacts (Theme 7). The elements of this Theme have subsequently been included in Themes 3 and 9.

When is the programme active?

The programme started in April 2007 with funding for 5 years.

Brief summary of the programme fieldwork/data

Programme fieldwork and data collection are to be achieved through:

The data is to be fed into models for validation and future projections. Greater detail can be found in the Theme documents.


Oceans 2025 Theme 10

Oceans 2025 is a strategic marine science programme, bringing marine researchers together to increase people's knowledge of the marine environment so that they are better able to protect it for future generations.

Theme 10: Integration of Sustained Observations in the Marine Environment spans all marine domains from the sea-shore to the global ocean, providing data and knowledge on a wide range of ecosystem properties and processes (from ocean circulation to biodiversity) that are critical to understanding Earth system behaviour and identifying change. They have been developed not merely to provide long-term data sets, but to capture extreme or episodic events, and play a key role in the initialisation and validation of models. Many of these SOs will be integrated into the newly developing UK Marine Monitoring Strategy - evolving from the Defra reports Safeguarding our Seas (2002) and Charting Progress (2005), thus contributing to the underpinning knowledge for national marine stewardship. They will also contribute to the UK GOOS Strategic Plan (IACMST, 2006) and the Global Marine Assessment.

Weblink: http://www.oceans2025.org/


Oceans 2025 Theme 10, Sustained Observation Activity 4: The Extended Ellett Line

The Ellett Line (begun in 1975 and since 1996 the Extended Ellett Line from Scotland to Iceland) crosses important north Atlantic Meridional Overturning Circulation (MOC) components and thus provides an additional contribution to understanding the north Atlantic response to climate change. Sustained Observation Activity (SO) 4 will repeat this section annually collecting a wide variety of physical and biogeochemical measurements, and will, to enhance the time variable component, make use of Argo floats and gliders. SO 4 will be implemented by physical, biological and chemical scientists at the National Oceanography Centre, Southampton (NOCS) and the Scottish Association for Marine Science (SAMS).

SO 4 formally contributes to the Department for Environment, Food and Rural Affairs (DEFRA)-funded Marine Environmental Change Network (MECN). Established in 2002 to coordinate and promote the collection and utilisation of marine time-series and long-term data sets, the goal of the network is to use long-term marine environmental data from around the British Isles and Ireland to separate natural fluctuations from global, regional and local anthropogenic impacts.

The specific deliverables for SO 4 are:

More detailed information on this Work Package is available at pages 15 - 16 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10

Weblink: http://www.oceans2025.org/


Data Activity or Cruise Information

Cruise

Cruise Name D351
Departure Date 2010-05-11
Arrival Date 2010-05-28
Principal Scientist(s)Jane F Read (National Oceanography Centre, Southampton)
Ship RRS Discovery

Complete Cruise Metadata Report is available here


Fixed Station Information


No Fixed Station Information held for the Series


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