Search the data

Metadata Report for BODC Series Reference Number 1660996


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Lever Action Niskin Bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Andy Rees
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) UKSOLAS
 

Data Identifiers

Originator's Identifier D325_CTD_PIGX_200:CTD_E085_TIT
BODC Series Reference 1660996
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2007-12-07 09:24
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 20.66548 N ( 20° 39.9' N )
Longitude 24.96747 W ( 24° 58.0' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 5.2 m
Maximum Sensor or Sampling Depth 95.1 m
Minimum Sensor or Sampling Height 4635.7 m
Maximum Sensor or Sampling Height 4725.6 m
Sea Floor Depth 4730.8 m
Sea Floor Depth Source PEVENT
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
CPHLFLP51Milligrams per cubic metreConcentration 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
CPHLFLSD1Milligrams per cubic metreConcentration standard deviation 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
FIRSEQID1DimensionlessBottle firing sequence number
ROSPOSID1DimensionlessBottle rosette position identifier
SAMPRFNM1DimensionlessSample reference number

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

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.

Deployment

Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

Extracted chlorophyll concentrations analysed by fluorometry for UK SOLAS cruise Discovery D325 (INSPIRE)

Originator's Data Acquisition and Analysis

Samples for chlorophyll analyses by bench fluorometry were taken from one CTD cast at each of the six sites occupied during the cruise. All came from the titanium CTD rig rosette sampler. Seawater samples (150 - 250 ml) were collected from the rosette bottles and filtered onto 47mm 0.2 µm polycarbonate filters. These were extracted in 90% acetone at -20 °C overnight. Chlorophyll a was determined according to the method of Welschmeyer (1994) using a Turner instruments fluorometer. Measurements were made in triplicate.

References Cited

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

BODC Data Processing Procedures

Data were received by BODC in a spreadsheet format file (BODC Chlphyll New.xls). The following metadata fields were included in the spreadsheet: station, date, time, event, CTD bottle number, nominal depth and volume filtered.

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

Orginator's Parameter Units Description BODC Parameter Code Units Comments
Chl a mean µg L-1 Concentration of chlorophyll a per unit volume of seawater CPHLFLP5 mg m-3 n/a
Chl a s.d. µg L-1 Concentration standard deviation of chlorophyll a per unit volume of seawater CPHLFLSD mg m-3 n/a

The data were banked according to BODC standard procedures for discrete sample data. The data were tagged with the appropriate parameter code, then loaded into BODC Samples Database. No unit conversion was required since the units the originator had assigned to the data were analagous with those of the BODC parameter code.

Data Quality Report

The depths submitted with data from cast CTD_F110_TIT conflicted with those associated with the same cast and bottle number in the original CTD sensor data files. BODC understand the data originator to have used depth rather than bottle number to distinguish samples within a cast. Data from this cast were therefore linked to the BODC bottle metadata records using depth rather than the bottle reference number. Due to this, users should treat the data from this cast with caution.


Project Information

UK Surface Ocean Lower Atmosphere Study

The UK Surface Ocean Lower Atmosphere Study (UK SOLAS) is the UK's contribution to the international SOLAS programme.

UK SOLAS formed interdisciplinary teams to address three primary aims

  • To determine the mechanisms controlling rates of chemical transfer and improve estimates of chemical exchanges
  • To evaluate the impact of these exchanges on the biogeochemistry of the surface ocean and lower atmosphere and on feedbacks between the ocean and atmosphere
  • To quantify the impacts of these boundary layer processes on the global climate system

UK SOLAS started in 2003, to run for seven years. The programme was funded by the Natural Environment Research Council.

Funded projects

In total, 19 projects have been funded by UK SOLAS, over four funding rounds.

Project Title Short Title Principal Investigator
Impact of atmospheric dust derived material and nutrient inputs on near-surface plankton microbiota in the tropical North Atlantic Dust Eric Achterberg
The role and effects of photoprotective compounds in marine plankton - Steve Archer
Field observations of sea spray, gas fluxes and whitecaps SEASAW Ian Brooks
Factors influencing the biogeochemistry of iodine in the marine environment - Lucy Carpenter
Global model of aerosol processes - effects of aerosol in the marine atmospheric boundary layer GLOMAP Ken Carslaw
Ecological controls on fluxes of dimethyl sulphide (DMS) to the atmosphere - David Green
Dust outflow and deposition to the ocean DODO Ellie Highwood
Investigation of near surface production of iodocarbons - rates and exchanges INSPIRE Gill Malin
Reactive halogens in the marine boundary layer RHaMBLe Gordon McFiggans
The role of bacterioneuston in determining trace gas exchange rates - Colin Murrell
Measuring methanol in sea water and investigating its sources and sinks in the marine environment - Phil Nightingale
The impact of coastal upwellings on air-sea exchange of climatically important gases ICON Carol Robinson
The Deep Ocean Gas Exchange Experiment DOGEE Rob Upstill-Goddard
High wind air-sea exchanges HiWASE Margaret Yelland
Aerosol characterisation and modelling in the marine environment ACMME James Allan
3D simulation of dimethyl sulphide (DMS) in the north east Atlantic - Icarus Allen
Processes affecting the chemistry and bioavailability of dust borne iron - Michael Krom
The chemical structure of the lowermost atmosphere - Alastair Lewis
Factors influencing the oxidative chemistry of the marine boundary layer - Paul Monks

UK SOLAS has also supported ten tied studentships, and two CASE studentships.

Fieldwork

UK SOLAS fieldwork has included eight dedicated research cruises in the North Atlantic Ocean. Continuous measurements were made aboard aboard the Norwegian weather ship, Polarfront, until her decommission in 2009. Time series have been established at the SOLAS Cape Verde Observatory, and at the Plymouth Marine Laboratory L4 station. Experiments have taken place at the Bergen mesocosm facility.

A series of collaborative aircraft campaigns have added complementary atmospheric data. These campaigns were funded by UK SOLAS, African Monsoon Multidisciplinary Analyses (AMMA-UK), Dust and Biomass Experiment (DABEX) and the Facility for Airborne Atmospheric Measurements (FAAM).

Weblink: http://www.nerc.ac.uk/research/programmes/solas/


Data Activity or Cruise Information

Cruise

Cruise Name D325
Departure Date 2007-11-13
Arrival Date 2007-12-18
Principal Scientist(s)Gill Malin (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
B nominal value
Q value below limit of quantification