Metadata Report for BODC Series Reference Number 1094439


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Technicon AutoAnalyzer II colorimetric autoanalyser  colorimeters; autoanalysers
Non-toxic sea water supply  continuous water samplers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Mr Alan Pomroy
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Project(s) Atlantic Meridional Transect (AMT)
 

Data Identifiers

Originator's Identifier AMT2_GPUMP_Pomroy_nuts
BODC Series Reference 1094439
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1996-04-23 00:17
End Time (yyyy-mm-dd hh:mm) 1996-05-21 17:29
Nominal Cycle Interval -
 

Spatial Co-ordinates

Southernmost Latitude 50.11982 S ( 50° 7.2' S )
Northernmost Latitude 49.34382 N ( 49° 20.6' N )
Westernmost Longitude 56.93368 W ( 56° 56.0' W )
Easternmost Longitude 6.74027 W ( 6° 44.4' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 6.0 m
Maximum Sensor Depth 6.0 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
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 -
 

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)
ALATGP01 1 Degrees Lat_GPS Latitude north (WGS84) by unspecified GPS system
ALONGP01 1 Degrees Lon_GPS Longitude east (WGS84) by unspecified GPS system
BOTTFLAG 1 Dimensionless C22_flag Sampling process quality flag (BODC C22)
NTRIAADZ 1 Micromoles per litre NO2_Filt_ColAA Concentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate
NTRZAADZ 1 Micromoles per litre NO3+NO2_Filt_ColAA Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate
PHOSAADZ 1 Micromoles per litre PO4_Filt_ColAA Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate
SAMPRFNM 1 Dimensionless SampRef Sample reference number
SLCAAADZ 1 Micromoles per litre SiOx_Filt_ColAA Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate
 

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 - see processing documentation

Data quality information is included in the general documentation for this series. Please read.


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

Technicon AutoAnalyzer II (AAII)

The AAII is a segmented flow analyzer used for automated colorimetric analysis. The apparatus uses 2 mm diameter glass tubing and pumps reagents at flow rates of 2 to 3 ml s -1 , producing results at a typical rate of 30 to 60 samples per hour. The system comprises an autosampler, peristaltic pump, chemistry manifold a detector and a data acquisition software.

This instrument was replaced by the AA3 in 1997 which was upgraded to the AA3 HR systems in 2006.

Specifications

Frequency 420 kHz
Beam width 1.8° at -3 dB
Pulse lenght 0.1 m
Acoustic range precision ± 2.5 cm
Sampling rate 1 Hz
Tilt accuracy ± 0.5°
Tilt resolution ± 0.01°

Diameter of ensonified area
(dependent on acoustic range)

0.9 m for 30 m range

3.1 m for 100 m range

6.3 m for 200 m range

Non-toxic (underway) sea water supply

A source of uncontaminated near-surface (commonly 3 to 7 m) seawater pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the non-toxic supply. The system is also referred to as the underway supply.

AMT2 Nutrient (micromolar) measurements from underway surface samples

Originator's Protocol for Data Acquisition and Analysis

This data originates from analyses of samples taken from the ship's non-toxic supply on 158 occasions during the cruise.

Concentrations of dissolved nitrate, nitrite, phosphate and silicate were measured using a 4-channel Technicon autoanalyser. Underway samples, taken from the ship's non-toxic supply at approximately 4 hourly intervals were analysed. All 4 nutrients being successfully determined in 99.4% of the underway samples.

On the whole, the system was stable and reliable from day to day. There were some initial problems with bubble patterns at the beginning of the cruise due, in part, to the severity of the weather on leaving Port Stanley. Lubrication of the autoanalyser pumps rectified the majority of the hydraulic problems, indicating that the pump oil had dried out between AMT-1 and AMT-2 and that lubrication of the pumps and rollers should become standard procedure prior to commencing analysis on subsequent cruises. Problems with the nitrite channel persisted for a further 3 days before a constricted return line was identified. Following its replacement, no further problems were encountered.

References Cited

Instrumentation Description

Not relevant to this data set.

BODC Data Processing Procedures

Data were submitted to BODC in Microsoft Excel spreadsheet format and saved in the BODC archive with reference PML980063. Sample metadata were checked against information held in the cruise report - there was one discrepancy with what appeared to be a typing error in the Julian Day data in the originator's file. The Julian Day was given as 136 with time 12:00 but was positioned in between other JD 126 data in the original file. Also the data was the same before and after for the samples analysed during JD 126 but results in a spike on all four parameters when placed at JD 136. The data has been loaded against a sample collected at 12:15 on JD126. There were no nitrite data for 4 samples indicated by N/A in originator's file. The data were assigned parameter codes defined in BODC parameter dictionary. Data were loaded into BODC's database using established BODC data banking procedures.

A parameter mapping table is provided below;

Originator's Parameter Units Description BODC Parameter Code Units Comments
Nitrate+Nitrite µmol l -1 Concentration of nitrate+nitrite {NO 3 +NO 2 } per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis NTRZAADZ µmol l -1 -
Nitrite µmol l -1 Concentration of nitrite {NO 2 } per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis NTRIAADZ µmol l -1 -
Phosphate µmol l -1 Concentration of phosphate {PO 4 } per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis PHOSAADZ µmol l -1 -
Silicate µmol l -1 Concentration of silicate {SiO 4 } per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis SLCAAADZ µmol l -1 -

Data Quality Report

BODC has not been advised of any data quality checks carried out by the data originator. A number of negative data values have been flagged suspect with BODC flag 'M'.

Problem Report

Not relevant to this data set.


Project Information

The Atlantic Meridional Transect (AMT) - Phase 1 (1995-2000)

Who was involved in the project?

The Atlantic Meridional Transect (AMT) programme was designed by and implemented as a collaboration between Plymouth Marine Laboratory (PML) and Southampton Oceanography Centre (SOC). The programme was hosted by Plymouth Marine Laboratory and involved additional researchers from UK and international universities throughout its duration.

What was the project about?

When AMT began in 1995 the programme provided a platform for international scientific collaboration, including the calibration and validation of SeaWiFs measurements and products. The programme provided an exceptional opportunity for nationally and internationally driven collaborative research and provided a platform for excellent multi-disciplinary oceanographic research. As an in situ observation system, the data collected by the AMT consortium informed on changes in biodiversity and function of the Atlantic ecosystem during this period of rapid change to our climate and biosphere.

The scientific aims were to assess:

When was the project active?

The first phase of the AMT programme ran from 1995 to 2000 and consisted of a total of 12 cruises. A second phase of funding allowed the project to continue for the period 2002 to 2006 with a further 6 cruises.

Brief summary of the project fieldwork/data

The AMT programme undertook biological, chemical and physical oceanographic research during the annual return passage of the RRS James Clark Ross between the UK and the Falkland Islands or the RRS Discovery between the UK and Cape Town, a distance of up to 13,500 km. This transect crossed a range of ecosystems from sub-polar to tropical and from euphotic shelf seas and upwelling systems to oligotrophic mid-ocean gyres. The transect route was covered north-south in September/October and south-north in April/May of each year.

The measurements of hydrographic and bio-optical properties, plankton community structure and primary production completed on the first 12 transects (1995-2000) represent the most coherent set of repeated biogeochemical observations over ocean basin scales. This unique dataset has led to several important discoveries concerning the identification of oceanic provinces, validation of ocean colour algorithms, distributions of picoplankton, identifying new regional sinks of pCO2 and variability in rates of primary production and respiration.

Who funded the project?

The programme was funded by the Natural Environment Research Council (NERC) and further support was received from the National Aeronautics and Space Administration (NASA) with equipment and funding from the Sea-viewing Wild Field-of-view Sensor (SeaWiFS) project.


Data Activity or Cruise Information

Cruise

Cruise Name JR19960422 (AMT2, JR13)
Departure Date 1996-04-22
Arrival Date 1996-05-22
Principal Scientist(s)David Robins (Plymouth Marine Laboratory)
Ship RRS James Clark Ross

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