Metadata Report for BODC Series Reference Number 895626


Metadata Summary

Data Description

Data Category Water column chemistry
Instrument Type
NameCategories
EnviroTech LLC NAS-2E Nutrient Analyser  nutrient analysers
Instrument Mounting subsurface mooring
Originating Country United Kingdom
Originator Dr Richard Lampitt
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) ANIMATE
 

Data Identifiers

Originator's Identifier PAP1_102002_NIT_2400
BODC Series Reference 895626
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2002-10-09 10:28
End Time (yyyy-mm-dd hh:mm) 2003-07-08 10:28
Nominal Cycle Interval 28800.0 seconds
 

Spatial Co-ordinates

Latitude 48.98330 N ( 48° 59.0' N )
Longitude 16.42400 W ( 16° 25.4' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 65.0 m
Maximum Sensor Depth 65.0 m
Minimum Sensor Height 4779.0 m
Maximum Sensor Height 4779.0 m
Sea Floor Depth 4844.0 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 Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

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
NTRZNS01 1 Micromoles per litre NO3+NO2_Unfilt_Colin-Situ Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ nutrient analysis system
PPSAPS01 1 Metres WColHt+AtPr Depth below surface of the water body by semi-fixed in-situ pressure sensor and conversion to depth using unspecified algorithm
 

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

NAS-2E in situ Nutrient Analyser

The NAS-2E in situ Nutrient Analyser is a submersible instrument for the automated measurement of dissolved nutrient concentrations in marine and fresh waters. It employs colorimetric wet-chemistry to determine nutrient concentrations by measuring the light absorbance of a coloured dye produced by a chemical reaction. The instrument, manufactured by WS Ocean Systems Ltd., Hans, UK, is designed for deployment on moorings. Versions have been developed for nitrate+nitrite, phosphate and silicate. The use of standard wet-chemistry techniques ensure comparability with laboratory results.

References for manufacturer's standard chemical methods are:

although these may be altered by the user.

The system utilizes a syringe pump and rotary valve to acquire and react discrete water samples. For nitrate+nitrite analysis, the samples is first passed over a copper-cadmium column to reduce nitrate to nitrite before reacting with the reagents to form the dye. Once the reaction takes place the sample is injected into the colorimeter where optical beam attenuation is measured. An integral system controller drives the syringe and valve via stepper motors and records the colorimeter readings.

The analysis routines include blank measurements for turbidity and optical fouling. An on-board calibration standard is periodically analysed to ensure the continuous integrity of the results. Programmable controls allows the operator to develop and program alternative chemical routines. All raw data are recorded as voltages representing beam transmission through the sample within the colorimeter pathlength. Following recovery of the instrument, raw data are downloaded to a PC and converted to absorbance units and nutrient concentration using manufacturer's calibration and on- board blank and standard readings.

Manufacturer's specification:

Wavelength 560 nm 880 nm
Accuracy 2% of range 5% of range
Sensitivity 0.5% of range 2.5% of range

Level of detection (PL = colorimeter path length):

Nitrate (µM) 0-300 with 5 mm PL
  0-60 with 10 mm PL
  0-10 with 20 mm PL
  0-5 with 40 mm PL
Silicate (µM) 0-60 with 10 mm PL
  0-10 with 20 mm PL
Phosphate (µM) 0-3 with 20 mm PL
  0-1 with 40 mm PL

PAP mooring Envirotech NAS2E sensor data processing document

This document outlines the procedures undertaken to process and quality assure the NAS2E nutrient analyser data collected on moorings deployed as part of the PAP project.

Originator's processing

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

Calibration

No instrument serial numbers or calibration details were supplied in any of the mooring deployment cruise reports. The data originators were contacted by BODC but were unable to provide any further information.

Quality control

The data originator's processing has quality indicators to the data for inconsistent, bad, doubtful or missing values- these were mapped to BODC flags during transfer via the table below:

Originator's Flag BODC Flag
0 - No quality control = None
1 - Correct = None
2 - Inconsistent = L
3 - Doubtful = L
4 - Bad = L
9 - Missing = N

BODC processing

Data are received after the data originator's processing has been completed. 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:

Originator's variable Unit Definition BODC parameter code Units Unit conversion Comments
Year year Year AADYAA01 days - Combined with Month and Day to form a date and transferred
Month month Month AADYAA01 days - Combined with Year and Day to form a date and transferred
Day day Day AADYAA01 days - Combined with Year and Month to form a date and transferred
Hour hour hours AAFDZZ01 days /24 Combined with minutes and seconds to form part of a decimal day and transferred
Minute minute minutes AAFDZZ01 days /24 Combined with hours and seconds to form part of a decimal day and transferred
Second second seconds AAFDZZ01 days /24 Combined with hours and minutes to form part of a decimal day and transferred
Depth metres Depth below surface PPSAPS01 metres - Transferred
Nitrate micromol/l Corrected Nitrate Concentration NTRZNS01 Micromoles per litre - Transferred

The remaining variables in the originator's file have not been transferred as they are either uncorrected nitrate values, or Microcat temperature, conductivity and salinity data which have been banked with BODC in a separate accession.

Data Quality

There is a ~340m difference in the depth of the instrument over the duration of the time series. There is no mention of mooring 'knock-down' in either the deployment or recovery cruise reports, and data originator Maureen Pagnani has no further information on the subject. However, other PAP recovery cruise reports (i.e. the one for D296, p. 11) mentions that high current speeds have knocked down the mooring so the sensor package descends by 160 m on occasions. Additionally, a search on Google identified the following document:
http://www.noc.soton.ac.uk/nmf/usl/gxg/CaseNotes3_RAPID_wb4_2000703.pdf
in which part of a mooring was 'knocked down' from its operational depth of 400 m to 853 m (p.21). With no more relevant information to refer to, and no particular reason to query the validity of the data gathered by the sensor, even at large depth variations from its stated deployment depth, it is suggested that a knockdown of as much as 300 m is at least plausible.


Project Information

ANIMATE- Atlantic Network on Interdisciplinary Moorings and Time-series for Europe

Scientific Rationale

The objective of the ANIMATE program is to make time series measurements from deep water observatories in the North Atlantic. ANIMATE is a European program coordinated by Prof. Uwe Send at IFM, Kiel and will establish deep ocean observing sites at three contrasting locations. The locations are CIS (Central Irminger Sea) east of Greenland, ESTOC (Estación Europea de Series Temporales del Oceano, Islas Canarias) about 100km north of the Canary Islands, and PAP (Porcupine Abyssal Plain). The measurements in the first instance are somewhat basic but nevertheless encapsulate the crucial processes that drive the biogeochemistry of any oceanic region.

At all three sites at about 15m depth (100m off the Canary Islands) there are frequent measurements of CO2 concentration, nutrients and fluorescence as a proxy for phytoplankton concentration. Throughout the top 100m there are measurements at about a dozen depths of salinity and temperature and this will enable us to characterise the complete annual cycle of the physics of the upper ocean. It is this physics which determines to a great extent the concentrations of limiting nutrients in the upper sunlit zone and the growth of phytoplankton. Phytoplankton are responsible for about half of the oceanic CO2 uptake and, as such, a better understanding of the relationship between physics, nutrients, phytoplankton growth and CO2 concentration is essential if we are to understand the processes and predict future responses of the oceans to anthropogenic CO2 release.

The ANIMATE project is funded by the EU in 2002-2004 as the 5th framework project EVR1-CT-2001-40014 and also funded in part by EU-funded projects Mersea IP and Carbo-Ocean.

References

Billett, D.S.M., Bett B.J., Reid, W.D.K., Boorman, B. and Priede, M. Long-term change in the abyssal NE Atlantic: The 'Amperima Event' revisited. Deep Sea Research II; PAP special volume (Submitted)

Hartman. S., Larkin. K. E., Lampitt, R. S, Koeve, W., Yool, A., Körtzinger, A., Hydes, D.J. (This volume) Seasonal and inter-annual biogeochemical variations at PAP (49°N, 16.5°W) 2003-2005. Deep Sea Research II; PAP special volume (Submitted)

Gooday, A et al. Long term change in foraminiferans Deep Sea Research II, PAP special volume (Submitted)

Martin, A.P., Lucas, M.I., Painter, S.C., Pidcock, R., Prandke H., Prandke,H., Stinchcombe, M.C. (2008) The supply of nutrients due to vertical turbulent mixing: a study at the Porcupine Abyssal Plain study site (49° 50'n 16° 30'w) in the northeast Atlantic. Deep Sea Research II, PAP special volume (Submitted)


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2002-10-09
End Date (yyyy-mm-dd) 2003-07-08
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPAP1_102002
Platform Categorysubsurface mooring

Moored Instrument Rig PAP1_102002

This rig was deployed as part of the Porcupine Abyssal Plain (PAP) observatory project. 'PAP1_102002' refers to the deployment of mooring number 1 in October 2002 ('102002') located at the PAP Observatory. This was the second deployment of this mooring configuration at the PAP site, under this project.

Deployment Cruise RRS Discovery D266
Recovery Cruise FS Poseidon PO300_1

This rig was anchored by a 1200 kg weight and was kept erect by groups of sub-surface floats attached along the mooring. The instrument depths stated below are taken from the mooring recovery sheet in the cruise report for PO300_1.

Instruments deployed on the rig

Depth Instrument
40 m NAS2E + HS2 + SAMI
40 m Sea-Bird SBE 37-IM with pressure sensor (SN 2486)

Other Series linked to this Data Activity - 1225945

Cruise

Cruise Name D266
Departure Date 2002-09-27
Arrival Date 2002-10-24
Principal Scientist(s)Imants G Priede (University of Aberdeen, Oceanlab)
Ship RRS Discovery

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NamePorcupine Abyssal Plain (PAP)
CategoryOffshore location
Latitude49° 0.00' N
Longitude16° 30.00' W
Water depth below MSL4800.0 m

Porcupine Abyssal Plain (PAP) Observatory

The Porcupine Abyssal Plain (PAP) observatory is a site at which moorings were deployed in the Northeastern Atlantic, as part of the ANIMATE (Atlantic Network of Interdisciplinary Moorings and Time-series for Europe), MERSEA (Marine Environment and Security for the European Area) and then EuroSITES projects. The PAP site is centred at latitude 49° N and longitude 16.5° W. Moorings have occupied this region since 2002 and are typically deployed for 12 months.

Data summary

Mooring deployment Temperature salinity pressure ADCP Chlorophyll Sediment trap Current meter Nitrate Carbon dioxide Oxygen Irradience
Real time Delayed mode Real time Delayed mode Real time Delayed mode Real time Delayed mode Real time Delayed mode Real time Delayed mode Real time Delayed mode
PAP1 Oct 2002-Jun 2003 Data Data Data NT UD Data - Data NT Data NT SF - - - -
PAP2 Jul 2003-Nov 2003 CF Data Data NT Data Data - Data NT Data NT Data - - - -
PAP3 Nov 2003-Jun 2004 Data Data Data NT Data Data - Data NT Data NT Data - - - -
PAP4 Jun 2004-Jul 2005 Data Data Data NT Data Data - Data NT UD NT Data - - - -
PAP5 Jul 2005-Jun 2006 Data Lost Lost NT Lost Data - Data NT Lost NT Lost - - - -
PAP6 Jul 2006-Jul 2007 ND ND ND ND ND Data - Data ND ND ND ND - - - -
PAP7 Jun 2007-Aug 2007 Data Lost ND Data Data NYR - NYR SF SF NT Data - - - -
PAP 200905 May 2009-Jul 2009 Data Data - Data Data - - - Data Data SF SF - Data - -
PAP 201005 May 2010- Data - - Data - - Data - Data - Data - Data - Data -

Status Indicators

Indicator Description
Data Data received from mooring
Lost Data not received
SF Sensor failed
ND Not deployed
NYR Not yet recovered
CF Communications failure
UD Unusable data
NT Not telemetered

Other Series linked to this Fixed Station for this cruise - 1225945 1225957 1225969 1225970 1225982 1225994 1226008 1226021 1226033 1226045

Other Cruises linked to this Fixed Station (with the number of series) - CD158 (13) CE0716 (26) D341 (35) JC034T (4) JC071 (2) JC085 (9) M108 (1) PO300_1 (12) PO306 (14)


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