Intercalibration effort

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Intercalibration effort
Intercalibration The process, procedures,
and activities used to ensure that the
several laboratories engaged in a monitoring
program can produce compatible data. When
compatible data outputs are achieved and this
situation is maintained, the laboratories can be
said to be intercalibrated (Taylor,
1987). Intercalibration therefore is an active
process between laboratories that includes all
steps from sampling to analyses, with the goal of
achieving the same accurate results regardless of
the method or lab.
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AIMS
(1) Develop and test the US GEOTRACES sampling
systems and procedures for dissolved and
particulate TEIs. This equipment will be a
community resource for use in all future
US GEOTRACES cruises (2) Using these systems,
conduct a thorough intercalibration for all the
key GEOTRACES TEIs, and as many others as
possible, in the dissolved and particulate phases
through the participation of the worldwide TEI
community (3) Establish GEOTRACES Baseline
Stations in the western North Atlantic (BATS) and
eastern North Pacific (SAFe) as part of
the Intercalibration Cruises and (4) Fully
document the intercalibration results and create
US GEOTRACES User Manuals and Procedures for
future USsponsored GEOTRACES cruises.
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BATS cruise Leg 1 6-21st June 2008
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• Epoxy powder-coated clean rosette with 24 12 L
• GOFlo sampling bottles capable of being
  triggered 3 at a time while on the up-cast into
  uncontaminated water
• (2) CTD with oxygen probe, fluorometer, and
• transmissometer
• (3) 8000 m Kevlar/polyester conducting cable for
• deploying the clean CTD/rosette

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• (4) Dynacon traction winch with composite sheaves
  and line monitoring, plus a composite
  block/sheave to behung on the J frame
• (5) UNOLS-approved trace metal-clean sampling van
  for processing the clean water and particle
  samples
• (6) Shipping van for the rosette and winch also
  has a removable winch and CTD control room
• (7) Flatbed trailer to store and ship the 2 vans
  and all the associated equipment.
• Problems
• Level winder did not work well
• Deploying-tight wire angle-new A-Frame submitted
• Bottles close to the clean lab floor

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Filling a variety of sample bottles from the
Baseline profile using a capsule filter (left)
and 47 mm membrane filters. The capsule filter
was a 0.45 µm Teflon Osmonics capsule. The 47 mm
filters were 0.45 µm Supor and 0.4 µm Nuclepore
filters.
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• Comparison with other samplers
• MITESS (Boyle)
• Vanes (Wu)
• CLIVAR rosette
• No difference between samplers for Fe, Zn and Al
  was observed onboard ship.
• Vane samplers and CLIVAR rosette were used to
  collect a full water prolife for dissolved trace
  elements comparison with the GEOTRACES rosette
  for lab based laboratories.

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Tanks Bottling for intercalibration
Bottling the GEOTRACES (below) The filtration
cartridges (upper left) and one of the pair of
tanks with the valves (lower left).
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Particulate Sampling
Particulate sampling with in-situ McLane
pumps Battery powered, 400-600L in 2
hours Deploy 8 pumps at one depth on rosette
- 3x per station /depth
Particulate MULVFS sampling Plugged into the
deck 1000L- 2000L in 2 hrs Can have up to 5 on
a wire but only goes to 1000 m
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Where we are at to date

• Inter calibration meeting 2-3rd April (report
  will be out soon)
• Next cruise (5th 29th May SAFe site and coastal
  site)
• Workshop-Jan-Feb 2010-finalise results and begin
  work on decimating results and writing GEPTRACES
  user manuals
• Overall for most elements sampling is excellent

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Cruise 2 only one leg

• New Speciation and Aerosols
• Surface tank samples for dissolved TM
• Focus on filtration-filter type
• Digestion procedures for particulate trace
  metals-blanks
• Sample storage-freezing vs drying
• Nutrients-more labs involved for long wave liquid
  core guide
• Hg-sparging and headspace
• Nd-dissolved more samples sending known std to
  all labs
• Th-Pa-Be- Particulate 231Pa (230Th) requires
  samples gt100 l in upper 1000 m-working on blanks,
  spike intercalibration and equilibration

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Elemental Co-ordinators

• Dissolved Trace Elements Ken Bruland,
  Bruland_at_ucsc.edu
• Particulate Trace elements Rob Sherrell,
  Sherrell_at_rutgers.edu
• Si isotopes - Mark Brzezinski,
  brzezins_at_lifesci.ucsb.edu
• N (and O) isotopes Karen Casciotti,
  kcasciotti_at_whoi.edu
• P (O isotopes) Albert Colman,
  colman_at_umbi.umd.edu
• Hg Carl Lamborg, clamborg_at_whoi.edu
• Metal stable isotopes Ed Boyle,
  eaboyle_at_mit.edu
• Nd and Hf Tina van de Flierdt,
  tina_at_ldeo.columbia.edu
• Os - Bernhard Peucker-Ehrenbrink,
  behrenbrink_at_whoi.edu
• Th - Ken Buesseler, kbuesseler_at_whoi.edu
• Ra Billy Moore, moore_at_geol.sc.edu
• Pb-, 210Po Mark Baskaran, ag4231_at_wayne.edu
• Aerosols - Bill Landing, wlanding_at_fsu.edu
• Speciation - Jim Moffett, moffett_at_usc.edu
• 130Th, 231Pa ,10Be- Bob Anderson,
  boba_at_ldeo.columbia.edu
• Pu,137Cs - Tim Kenna, tkenna_at_ldeo.columbia.edu