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.

(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. AIMS

BATS cruise: Leg st June 2008

(1)Epoxy powder-coated clean rosette with 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

(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

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.

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.

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).

Particulate sampling with in-situ McLane pumps Battery powered, L in 2 hours Deploy 8 pumps at one depth on “rosette” - 3x per station /depth Particulate Sampling 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

Where we are at to date Inter calibration meeting 2-3 rd April (report will be out soon) Next cruise (5 th – 29 th 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

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 231 Pa ( 230 Th) requires samples >100 l in upper 1000 m-working on blanks, spike intercalibration and equilibration

Elemental Co-ordinators Dissolved Trace Elements – Ken Bruland, Particulate Trace elements – Rob Sherrell, Si isotopes - Mark Brzezinski, N (and O) isotopes– Karen Casciotti, P (O isotopes) – Albert Colman, Hg – Carl Lamborg, Metal stable isotopes – Ed Boyle, Nd and Hf – Tina van de Flierdt, Os - Bernhard Peucker-Ehrenbrink, Th - Ken Buesseler, Ra – Billy Moore, Pb-, 210 Po – Mark Baskaran, Aerosols - Bill Landing, Speciation - Jim Moffett, 130 Th, 231 Pa, 10 Be- Bob Anderson, Pu, 137 Cs - Tim Kenna,