Metadata Report for BODC Series Reference Number 774762

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

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

Aanderaa Recording Current Meter Model 7/8

Manufacturer's specifications: recording unit height 49.5cm (RCM8 52.0cm), diameter 12.8cm, vane size 48.5x50.0cm. Meter is designed for depths down to 2000m (RCM8 6000m). It incorporates a spindle which is shackled to the mooring line. The meter is attached to the spindle through a gimbal mounting which permits a maximum 27° deviation of the spindle from the vertical, the meter still remaining horizontal.

Meter comprises :

1. Paddle wheel rotor magnetically coupled to an electronic counter

2. Vane, which aligns instrument with current flow, has a balance weight ensuring static balance and tail fins to ensure dynamic balance in flows up to 250cm/s.

3. Magnetic compass (needle is clamped to potentiometer ring) - direction recorded with 0.35° resolution, 5° accuracy for speeds 5 to 100cm/s, 7.5° accuracy for remaining speeds within 2.5 to 200cm/s range.

4. Quartz clock, accuracy better than 2 sec/day within temperature range 0 to 20°C.

5. Thermistor (temperature sensor), standard range -2.46 to 21.48°C (max on high range 36.04°C), accuracy 0.05°C, resolution 0.1 per cent of range, 63 per cent response time 12sec.

6. Inductive cell conductivity sensor (optional), range 0 to 70mmho/cm standard resolution 0.1 per cent of range.

7. Silicon piezoresistive bridge, standard range 0 to 3000 psi (RCM8 to 9000 psi), resolution 0.1% of range.

8. Self balancing potentiometer which converts the output from each sensor into a 10 bit binary number for storage on magnetic tape.

9. Associated electronics.

A built-in clock triggers the instrument at preset intervals and up to six channels are sampled in sequence. Channel 1 is a fixed reference reading for control purposes and data identification. Channels 2, 3 and 4 represent measurement of temperature, conductivity and pressure. Channels 5 and 6 represent the VECTOR AVERAGED current speed and direction since the previous triggering of the instrument. The number of rotor revolutions and the direction is sampled every 12 seconds and broken into North and East components. Successive components are added and recorded as speed and direction. For recording intervals longer than 10 minutes, speed and direction are sampled 1/50th of recording interval.

It has become common practice in some laboratories to deploy these meters as temperature and conductivity loggers without current measuring capabilities.

The following link will provide the manufacturer specifications:

PAP Current Meter Data Processing Notes

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

The contents of the Data Originator's 'readme' file for each of the current meters on mooring PAP0203 are included below:

File of temperature, current speed and current direction data collected at PAP3 mooring at 49.0N 16.5W Deployment between 12-Jul-2003 19:01 and 24-Jun-2004 12:07

Created on 28-Jul-2004

Sensor Aanderaa RCM8 Serial-No 9415

Deployed during cruise Poseidon 300/1

Recovered during cruise Charles Darwin CD158

The data in this file are :-

year

month

day

hour

minute

temperature (Celsius)

current speed (cm/s)

current direction (degrees)

Data were measured at the nominal depth of 4702 metres, 100m above sea bed, which was 4802m

Quality Indicators are :-

0 No Quality Control

1 Correct

2 Inconsistent

3 Doubtful

4 Bad

5 Changed

8 Profile Interpolated at standard depth

9 Missing

File of temperature, current speed and current direction data collected at PAP3 mooring at 49.0N 16.5W Deployment between 12-Jul-2003 19:01 and 24-Jun-2004 12:00

Created on 28-Jul-2004

Sensor Aanderaa RCM8 Serial-No 11571

Deployed during cruise Poseidon 300/1

Recovered during cruise Charles Darwin CD158

The data in this file are :-

year

month

day

hour

minute

temperature (Celsius)

current speed (cm/s)

current direction (degrees)

Data were measured at the nominal depth of 3052 metres, 1750m above seabed, which was 4802m

Quality Indicators are :-

0 No Quality Control

1 Correct

2 Inconsistent

3 Doubtful

4 Bad

5 Changed

8 Profile Interpolated at standard depth

9 Missing

PAP mooring Aanderaa RCM8 current meter processing document

This document outlines the procedures undertaken to process and quality assure the Aanderaa RCM8 current meter data collected on a mooring deployed as part of the PAP project. Two current meters were deployed at different depths on the 'PAP3' mooring during a cruise on RV Poseidon in 2003 (PO300_1)

Originator's processing

The raw data are downloaded from the instrument and converted to ASCII format .csv files. During this process, an error of 180 degrees was introduced inadvertently to each measurement of current direction. This error was rectified during BODC processing, described later in this document.

Calibration

The two Aanderaa RCM8 current metres were calibrated prior to deployment, at the National Oceanography Centre (NOC).

BODC processing

Data were received after the data originator's processing had been completed. The data files were submitted in ASCII format as one file per instrument. Two corrections to direction were applied at this stage: one to rectify the 180 degree error described earlier, and the other to correct for magnetic declination. All directions measured by the instrument are relative to magnetic north and uncorrected in the data originator's post-processing, but have been subsequently corrected to true north by subtracting a magnetic declination of 8.75 decimal degrees from the the magnetic direction, as calculated from the following website:
http://www.ngdc.noaa.gov/geomagmodels/Declination.jsp
The values of the magnetic declination on the start and end dates of the current meter deployment were averaged to get the value -8.75 decimal degrees, rather than applying a time-varying correction to the data series (the variation in declination being less than the instrument's resolution).

Once the submitted data files are safely archived, the data undergo reformatting and banking procedures:

• The data files are transferred into a common format, a NetCDF subset.

• Standard parameter codes are assigned that accurately describe the data (see Parameter mapping section below).

• Unit conversions are applied, if necessary, so that units are standardised (see Parameter mapping section below).

• The data are screened visually and any spikes or instrument malfunctions can be clearly labelled with quality control flags.

• Comprehensive documentation is prepared describing the collection, processing and quality of each data series.

• Detailed metadata and documents are loaded to the database and linked to each series so that the information is readily available to future users.

Parameter mapping

The following describes the parameters contained in the originator's files and their mapping to BODC parameter codes:

All variables in the originator's file have been transferred.

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

Moored Instrument Rig PAP3_072003

This rig was deployed as part of the Porcupine Abyssal Plain (PAP) observatory project. 'PAP3_072003' refers to the deployment of mooring number 3 in July 2003 ('072003') located at the PAP Observatory. This was the second deployment of this mooring configuration at the PAP site, under this project.

This rig was anchored by a 750 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 metadata files in subaccession soc080077a.

Instruments deployed on the rig

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

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), EuroSITES, Oceans2025, Fix03 and CLASS 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.

Please note: Near Real Time data is only stored at BODC where delayed mode data were not recovered. All near real time data can be found at the OceanSites GDA and through IFREMER.

Data summary

Status Indicators

Related Fixed Station activities are detailed in Appendix 2

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: PAP3_072003

Related series for this Data Activity 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.

Appendix 2: Porcupine Abyssal Plain (PAP)

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.