Metadata Report for BODC Series Reference Number 1623574


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Non-toxic sea water supply  continuous water samplers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Rob Thomas
Originating Organization British Oceanographic Data Centre, Liverpool
Processing Status banked
Project(s) Oceans 2025 Theme 10 SO1:AMT
 

Data Identifiers

Originator's Identifier JC079_GPUMP_PIGX_3126:
BODC Series Reference 1623574
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2012-10-11 19:00
End Time (yyyy-mm-dd hh:mm) 2012-11-20 13:56
Nominal Cycle Interval -
 

Spatial Co-ordinates

Southernmost Latitude 46.46224 S ( 46° 27.7' S )
Northernmost Latitude 49.52527 N ( 49° 31.5' N )
Westernmost Longitude 53.35920 W ( 53° 21.6' W )
Easternmost Longitude 9.39215 W ( 9° 23.5' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 5.0 m
Maximum Sensor Depth 5.0 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Unspecified -
Sensor Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -
 

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
CPHLFLP5 1 Milligrams per cubic metre chl-a_water>0.2um_fluor Concentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >0.2um phase] by filtration, acetone extraction and fluorometry
 

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

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.

Extracted chlorophyll-a measurements from non-toxic underway supply samples collected during AMT22 (JC079)

Originator's Protocol for Data Acquisition and Analysis

Samples were taken from the non-toxic underway supply to provide a calibration for the continuous fluorometer measurements. During the cruise 143 samples were collected from the non-toxic underway system and processed for extracted chl-a measurement.

250 ml samples of seawater collected from the non-toxic supply were filtered through 47 mm diameter 0.2 µm polycarbonate filters. The chlorophyl-a was then extracted from the filters with 10ml 90% acetone for 24 hours while samples were stored in a freezer. The concentrations were then determined fluorometrically.

Instrumentation Description

Turner Designs Trilogy fluorometer with a non-acidified chl module (CHL NA #046) fitted

BODC Data Processing Procedures

Data were submitted on the Post-Cruise Archive and archived under BODC's accession number BOD120217. Sample metadata (date, time (UT), latitude and longitude) were provided and loaded to the database.

No unit conversion was necessary as the units the data were supplied in the files matched the units for the parameter codes in the BODC Parameter Dictionary.

A parameter mapping table is provided below;

Originator's Parameter Units Description BODC Parameter Code Units Comments
Chl-a mean µg l -1 Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate >0.2um phase] by filtration, acetone extraction and fluorometry CPHLFLP5 mg m -3 Units equivalent

Data Quality Report

There were no data quality issues reported at then end of the cruise.

These data were updated on 14/05/2014. A cross calibration between AMT cruises 20-23 using the same bench fluorometer revealed a correction factor needed to be applied to the discrete chl-a data for AMT22. Possibly a problem with the standard chl-a solution used for calibration of the bench fluorometer during the cruise. This correction has now been applied to these data. The correction applied was:

Corrected Chl-a = 0.7886 * Chl-a - 0.0012

Problem Report

Not relevant to this data set.


Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 1: The Atlantic Meridional Transect (AMT)

The Atlantic Meridional Transect has been operational since 1995 and through the Oceans 2025 programme secures funding for a further five cruises during the period 2007-2012. The AMT programme began in 1995 utilising the passage of the RRS James Clark Ross between the UK and the Falkland Islands southwards in September and northwards in April each year. Prior to Oceans 2025 the AMT programme has completed 18 cruises following this transect in the Atlantic Ocean. This sustained observing system aims to provide basin-scale understanding of the distribution of planktonic communities, their nutrient turnover and biogenic export in the context of hydrographic and biogeochemical provinces of the North and South Atlantic Oceans.

The Atlantic Meridional Transect Programme is an open ocean in situ observing system that will:

The specific objectives are:

The measurements taken and experiments carried out on the AMT cruises will be closely linked to Themes 2 and 5. The planned cruise track also allows for the AMT data to be used in providing spatial context to the Sustained Observation Activities at the Porcupine Abyssal Plain Ocean Observatory (SO2) and the Western Channel Observatory (SO10).

More detailed information on this Work Package is available at pages 6 - 9 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 JC079 (AMT22)
Departure Date 2012-10-10
Arrival Date 2012-11-24
Principal Scientist(s)Glen A Tarran (Plymouth Marine Laboratory)
Ship RRS James Cook

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