Metadata Report for BODC Series Reference Number 1657939


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 Prof Patrick Holligan
Originating Organization University of Southampton School of Ocean and Earth Science
Processing Status banked
Project(s) Atlantic Meridional Transect Phase2(AMT)
 

Data Identifiers

Originator's Identifier AMT17_GPUMP_PIGX_216:
BODC Series Reference 1657939
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2005-10-17 08:09
End Time (yyyy-mm-dd hh:mm) 2005-11-26 03:48
Nominal Cycle Interval -
 

Spatial Co-ordinates

Southernmost Latitude 35.82502 S ( 35° 49.5' S )
Northernmost Latitude 50.76409 N ( 50° 45.8' N )
Westernmost Longitude 38.93058 W ( 38° 55.8' W )
Easternmost Longitude 18.45216 E ( 18° 27.1' E )
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
CPHLFLP1 1 Milligrams per cubic metre chl-a_water>GF/F_fluor Concentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >GF/F 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.

AMT17 extracted chlorophyll-a measured fluorometrically from CTD bottle samples

Data Acquisition and Analysis

These data originate from analyses on samples collected from CTD rosette bottles for all successful CTD casts and some samples collected from the ship's non-toxic supply while on station.

Water samples (300-500 ml) from CTD bottles were filtered on 25 mm GF/F filters. At a small number of stations the 1% and 55% of surface light level samples were size-fractionated with 2 µm and 0.2 µm 25 mm polycarbonate filters. Filters were extracted in 90% acetone for 24 hrs and total chlorophyll-a measured with a TD-700 Turner Designs fluorometer following the procedure of Welschmeyer (1994) which minimises interference by chlorophyll-b. The fluorometer was calibrated with dilutions of a solution of pure chlorophyll-a (Sigma, UK) in 90% acetone, the concentration of which was determined spectrophotometrically after the cruise.

References Cited

Welschmeyer N.A., 1994. Fluorometric analysis of chlorophyll-a in the presence of chlorophyll-b and phaeopigments. Limnology and Oceanography, 39, 1985-1992.

Instrumentation Description

Not relevant to this dataset.

BODC Data Processing Procedures

Data were submitted to BODC in an Excel spreadsheet and accessioned under BODC archive SOC060480. Sample metadata were checked against information held in the database. There were a number of discrepancies between combination of depth and bottle number of the samples provided in the file and those recorded on the log sheets and in the Sea-Bird bottle log files. Resolution of these discrepancies are listed in the table below.

CTD cast Originator's Light Depth (%) Originator's Depth (m) Originator's CTD bottle number Sea-Bird log file bottle depth (m) Sea-Bird log file CTD bottle number Comments
CTD006t - 20 22 10.5 22 database depth link based on originator's CTD bottle number
CTD006t - 40 15 19 15 database depth link based on originator's CTD bottle number
CTD015s - 85 10 96 10 database depth link based on originator's CTD bottle number
CTD017t 97 2 24 12.4 24 database depth link based on originator's CTD bottle number
CTD017t 14 46 19 56 19 database depth link based on originator's CTD bottle number
CTD017t 1 105 14 114.9 14 database depth link based on originator's CTD bottle number
CTD021t 14 54 18 44.7 18 database depth link based on originator's CTD bottle number
CTD021t 1 114 9 102.1 9 database depth link based on originator's CTD bottle number
CTD043t 14 17 19 75.5 19 database depth link based on originator's CTD bottle number
CTD046t 0.1 261 4 272.1 8 database depth link based on depth provided by originator since CTD bottle 4 was fired at depth ~3500 m and this is unlikely to relate to the 0.1% light depth indicated for this sample
CTD059s - 60 12 29.7 12 database depth link based on originator's CTD bottle number

For the size-fractionated samples only the sum of the size-fractions were provided. There were two samples with replicate measurements provided and these were loaded as mean and standard deivation for these samples.

Parameter codes defined in BODC parameter dictionary were assigned to the variable. The units supplied in the spreadsheet were mg l -1 , however comparison with data values reported from onboard calibration in the Cruise Report and sensor range of fluorometer (from manufacturer's website) suggests this is an error and the data should be labelled mg m -3 (equivalent to µg l -1 ).

Data values loaded into BODC's database without any changes applied.

A parameter mapping table is provided below;

Originator's Parameter Units Description BODC Parameter Code Units Comments
Chlorophyll-a µg l -1 Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate >GF/F phase] by filtration, acetone extraction and fluorometry CPHLFLP1 mg m -3 n/a
- - Concentration standard deviation of chlorophyll-a {chl-a} per unit volume of the water body [particulate >GF/F phase] by filtration, acetone extraction and fluorometry CLSDFLP1 mg m -3 n/a
Chlorophyll-a >0.2 total µg l -1 Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate >0.2 um phase] by filtration, acetone extraction and fluorometry CPHLFLP4 mg m -3 n/a

Data Quality Report

There was no indication that the dataset had been quality controlled prior to submission to BODC.

Problem Report

Not relevant to this dataset.

AMT17 extracted chlorophyll-a measured fluorometrically from surface non-toxic supply samples

Data Acquisition and Analysis

These data originate from analyses on discrete samples collected every few hours from the ship's non-toxic supply.

Water samples (300-500 ml) from CTD bottles were filtered on 25 mm GFF filters. Filters were extracted in 90% acetone for 24 hrs and total chlorophyll-a measured with a TD-700 Turner Designs fluorometer following the procedure of Welschmeyer (1994) which minimises interference by chlorophyll-b. The fluorometer was calibrated with dilutions of a solution of pure chlorophyll-a (Sigma, UK) in 90% acetone, the concentration of which was determined spectrophotometrically after the cruise.

References Cited

Welschmeyer N.A., 1994. Fluorometric analysis of chlorophyll-a in the presence of chlorophyll-b and phaeopigments. Limnology and Oceanography, 39, 1985-1992.

Instrumentation Description

Not relevant to this dataset.

BODC Data Processing Procedures

Data were submitted to BODC in an Excel spreadsheet and accessioned under BODC archive SOC060480. Sample metadata (lat, lon, date and time) were loaded to the database.

Parameter codes defined in BODC parameter dictionary were assigned to the variable. The units supplied in the spreadsheet were mg l -1 , however comparison with data values reported from onboard calibration in the Cruise Report and sensor range of fluorometer (from manufacturer's website) suggests this is an error and the data should be labelled mg m -3 (equivalent to µg l -1 ).

Data values loaded into BODC's database without any changes applied.

A parameter mapping table is provided below;

Originator's Parameter Units Description BODC Parameter Code Units Comments
Chlorophyll-a µg l -1 Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate >GF/F phase] by filtration, acetone extraction and fluorometry CPHLFLP1 mg m -3 n/a

Data Quality Report

There was no indication that the dataset had been quality controlled prior to submission to BODC. No data values were flagged by BODC. Details of the calibration calculation can be found in the CTD processing notes.

Problem Report

Not relevant to this dataset.


Project Information

The Atlantic Meridional Transect - Phase 2 (2002-2006)

Who was involved in the project?

The Atlantic Meridional Transect Phase 2 was designed by and implemented by a number of UK research centres and universities. The programme was hosted by Plymouth Marine Laboratory in collaboration with the National Oceanography Centre, Southampton. The universities involved were:

What was the project about?

AMT began in 1995, with scientific aims to assess mesoscale to basin scale phytoplankton processes, the functional interpretation of bio-optical signatures and the seasonal, regional and latitudinal variations in mesozooplankton dynamics. In 2002, when the programme restarted, the scientific aims were broadened to address a suite of cross-disciplinary questions concerning ocean plankton ecology and biogeochemistry and the links to atmospheric processes.

The objectives included the determination of:

The data were collected with the aim of being distributed for use in the development of models to describe the interactions between the global climate system and ocean biogeochemistry.

When was the project active?

The second phase of funding allowed the project to continue for the period 2002 to 2006 and consisted of six research cruises. The first phase of the AMT programme ran from 1995 to 2000.

Brief summary of the project fieldwork/data

The fieldwork on the first three cruises was carried out along transects from the UK to the Falkland Islands in September and from the Falkland Islands to the UK in April. The last three cruises followed a cruise track between the UK and South Africa, only deviating from the traditional transect in the southern hemisphere. During this phase the research cruises sampled further into the centre of the North and South Atlantic Ocean and also along the north-west coast of Africa where upwelled nutrient rich water is known to provide a significant source of climatically important gases.

Who funded the project?

Natural Environment Research Council (NERC)


Data Activity or Cruise Information

Cruise

Cruise Name D299 (AMT17)
Departure Date 2005-10-15
Arrival Date 2005-11-28
Principal Scientist(s)Patrick M Holligan (University of Southampton School of Ocean and Earth Science)
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