Metadata Report for BODC Series Reference Number 1230333


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
General Oceanics GO-FLO water sampler  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Prof Tim Jickells
Originating Organization University of East Anglia School of Environmental Sciences
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) ACSOE
 

Data Identifiers

Originator's Identifier DI234_CTD_NUTS_121:CTD47
BODC Series Reference 1230333
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1998-07-03 12:40
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 59.42656 N ( 59° 25.6' N )
Longitude 21.53112 W ( 21° 31.9' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 2.3 m
Maximum Sensor or Sampling Depth 19.4 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth below surface of the water body
BOTTFLAG1DimensionlessSampling process quality flag (BODC C22)
NTRZAATX1Micromoles per litreConcentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
PHOSAATX1Micromoles per litreConcentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SAMPRFNM1DimensionlessSample reference number
SLCAAATX1Micromoles per litreConcentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis

Definition of BOTTFLAG

BOTTFLAGDefinition
0The sampling event occurred without any incident being reported to BODC.
1The filter in an in-situ sampling pump physically ruptured during sample resulting in an unquantifiable loss of sampled material.
2Analytical evidence (e.g. surface water salinity measured on a sample collected at depth) indicates that the water sample has been contaminated by water from depths other than the depths of sampling.
3The feedback indicator on the deck unit reported that the bottle closure command had failed. General Oceanics deck units used on NERC vessels in the 80s and 90s were renowned for reporting misfires when the bottle had been closed. This flag is also suitable for when a trigger command is mistakenly sent to a bottle that has previously been fired.
4During the sampling deployment the bottle was fired in an order other than incrementing rosette position. Indicative of the potential for errors in the assignment of bottle firing depth, especially with General Oceanics rosettes.
5Water was reported to be escaping from the bottle as the rosette was being recovered.
6The bottle seals were observed to be incorrectly seated and the bottle was only part full of water on recovery.
7Either the bottle was found to contain no sample on recovery or there was no bottle fitted to the rosette position fired (but SBE35 record may exist).
8There is reason to doubt the accuracy of the sampling depth associated with the sample.
9The bottle air vent had not been closed prior to deployment giving rise to a risk of sample contamination through leakage.

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

GO-FLO Bottle

A water sampling bottle featuring close-open-close operation. The bottle opens automatically at approximately 10 metres and flushes until closed. Sampling with these bottles avoids contamination at the surface, internal spring contamination, loss of sample on deck and exchange of water from different depths.

There are several sizes available, from 1.7 to 100 litres and are made of PVC with a depth rating of up to 500 m. These bottles can be attached to a rosette or placed on a cable at selected positions.

Nitrate, phosphate and silicate concentrations for ACSOE cruise Discovery 234

Originator's Protocol for Data Acquisition and Analysis

Samples for inorganic nutrient analyses were drawn from Niskin bottles deployed on the CTD rosette frame, from the trace metal clean GO-FLO bottles and from the surface underway pumped water supply into 25 ml sterilin coulter counter vials. They were kept refrigerated at 4 degree C until the analysis which commenced within 24 hours (but generally less) on all but the final days of the cruise when some samples collected on the passage leg home had to be stored for up to 50h. Analysis for dissolved nitrate and nitrite (henceforth nitrate), dissolved inorganic phosphorus (henceforth phosphate) and dissolved silicon (henceforth silicate) was undertaken on a Skalar San Plus autoanalyser following methods described by Kirkwood (1994) with no prefiltration and modifications as described in WOCE A23 JR10 cruise report and in WOCE SR1 JR27 cruise report.

The analytical instrument ran satisfactorily but occasional computer faults resulted in the need to derive concentrations manually from the chart paper readout. When compared, there was a good agreement between the manual and computer generated results however manual processing had a lower detection limit than computer processing. For silicate this changed from 0.05 µmol l-1 for the computer method to 0.5 µmol l-1 for the manual method and this affected the ability to quantify the very low silicate concentrations in some of the surface waters sampled.

Analytical accuracy was tested regularly against Sagami nutrient standard certified reference material (3 times for phosphate and nitrate and 4 times for silicate). The Sagami nutrient standard has certified value of 20, 2.0 and 100 µM respectively for nitrate, phosphate and silicate. Averaged measured values in µM were: 19.4 (SD 0.1) for the nitrate line, 1.78(SD 0.07) for the phosphate line and for the silicate, following a five-fold dilution, 20.2 (SD 0.8).

Estimated precision based on duplicate and triplicate analyses was 0.1 µM for nitrate and 0.02 µM for phosphate and silicate. Further information is available in the DI234 cruise report.

References Cited

Kirkwood D.S., 1994. Nutrients: Practical notes on their determination in seawater. ICES Techniques in Marine Environmental Sciences report 17. International Council for the Exploration of the Seas, Copenhagen, 25 pp.

BODC Data Processing Procedures

Data from CTD rosette, bottle cast and underway sampling were submitted to BODC in a spreadsheet format file containing nitrate + nitrite, phosphate and silicate concentrations.

Parameter codes defined in BODC parameter dictionary were assigned to the variables as follows:

Originator's Parameter Units Description BODC Parameter Code Units Comments
Nitrate µM Concentration of nitrate plus nitrite per unit volume of the water body NTRZAATX µmol l-1 none
Phosphate µM Concentration of phosphate per unit volume of the water body PHOSAATX µmol l-1 none
Silicate µM Concentration of dissolved silicate per unit volume of the water body SLCAAATX µmol l-1 none

The data were banked according to BODC standard procedures for samples data. The data from CTD rosette samples were merged to existing records in the BODC database by matching the originator's cast number and bottle depth with cast number and bottle depth held in BODC database. Metadata for the surface underway and bottle cast samples were checked against cruise report information and inserted new into BODC's database.

Data Quality Report

The data have been quality controlled by the originator and information related to data quality is available from the cruise report (DI234 cruise report). Values declared as below detection limit or as needing to be used with caution by the originator have been flagged appropriately by BODC.


Project Information

Atmospheric Chemistry Studies in the Oceanic Environment (ACSOE)

Introduction

ACSOE was a NERC Thematic Research Programme which investigated the chemistry of the lower atmosphere (0-12 km) over the oceans. The studies aimed to bring about a clearer understanding of natural processes in the remote marine atmosphere, and how these processes are affected by atmospheric pollution originating from the continents. This information is vital to help understand regional and global-scale changes in atmospheric chemistry and climate.

Aims and Objectives

The £3.9 million NERC-funded programme was instigated as a major UK contribution to this international scientific effort between 1995 and 2000. The overarching aim of ACSOE was to investigate the processes that control the production and fate of trace gases and particles (condensation nuclei and aerosols) in the atmosphere over the oceans. For convenience it was divided into three separate but linked activities:

  1. MAGE, Marine Aerosol and Gas Exchange - to study air-sea exchange especially of atmospherically-important gases produced by marine microorganisms, such as dimethyl sulphide (DMS) and carbon dioxide (CO2)
  2. OXICOA, Oxidising Capacity of the Ocean Atmosphere - a study of the tropospheric ozone budget and underlying chemistry
  3. ACE, Aerosol Characterisation Experiment - to investigate the development of aerosols and clouds in European air spreading out into the Atlantic Ocean

The project had several objectives including:

Project Co-ordination:

The programme was led by Professor Stuart Penkett of the University of East Anglia and involved over 100 scientists from leading British and International universities and institutes. Atmospheric data are held at BADC and data collected in the marine environment for the MAGE component of the programme are held at BODC.

Fieldwork description:

Fieldwork was carried out in 1996, 1997 and 1998 and involved air-, land- and sea-based measurements, coupled with modelling studies. Measurements were made at remote field sites (Mace Head, Ireland; Weybourne, Norfolk; Tenerife), from the NERC research vessels Challenger and Discovery and aboard the Meteorological Research Flight C-130 and the Cranfield Jetstream aircraft.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1998-07-03
End Date (yyyy-mm-dd) 1998-07-03
Organization Undertaking ActivityUniversity of East Anglia School of Environmental Sciences
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierDI234_CTD_CTD47
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for DI234_CTD_CTD47

Sample reference number Nominal collection volume(l) Bottle rosette position Bottle firing sequence number Minimum pressure sampled (dbar) Maximum pressure sampled (dbar) Depth of sampling point (m) Bottle type Sample quality flag Bottle reference Comments
101795   30.00        4.70    6.80    2.30 General Oceanics GO-FLO water sampler No problem reported    
101796   30.00       12.20   13.30    9.20 General Oceanics GO-FLO water sampler No problem reported    
101797   30.00       22.40   23.60   19.40 General Oceanics GO-FLO water sampler No problem reported    
101798   30.00       32.10   33.90   29.30 General Oceanics GO-FLO water sampler No problem reported    
101799   30.00       52.90   54.40   49.70 General Oceanics GO-FLO water sampler No problem reported    
101800   30.00      108.10  109.90  104.60 General Oceanics GO-FLO water sampler No problem reported    
101801   30.00      199.20  201.40  194.90 General Oceanics GO-FLO water sampler No problem reported    
101802   30.00      503.60  505.60  495.90 General Oceanics GO-FLO water sampler No problem reported    
101803   30.00     1011.10 1013.00  996.70 General Oceanics GO-FLO water sampler No problem reported    
101804   30.00     1518.10 1520.50 1496.20 General Oceanics GO-FLO water sampler No problem reported    
101805   30.00     2033.40 2035.70 2002.30 General Oceanics GO-FLO water sampler No problem reported    
101806   30.00     2893.40 2895.10 2844.20 General Oceanics GO-FLO water sampler No problem reported    

Please note:the supplied parameters may not have been sampled from all the bottle firings described in the table above. Cross-match the Sample Reference Number above against the SAMPRFNM value in the data file to identify the relevant metadata.

Cruise

Cruise Name D234
Departure Date 1998-06-06
Arrival Date 1998-07-09
Principal Scientist(s)Peter Liss (University of East Anglia School of Environmental Sciences)
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
Q value below limit of quantification