An introduction to the program

Bob AndersonCo-chair International GEOTRACES SSC

http://www.geotraces.org/

Mission

GEOTRACES

An international study of the marine biogeochemistry of trace elements and their isotopes (TEIs)

GEOTRACES guiding mission

“To identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions”

Motivation

MOTIVATION

Three decades of research by individual PIs provided relatively little progress in understanding marine biogeochemical cycles of TEIs.

A coordinated international strategy is needed to accelerate progress.

Marine organic geochemistry community may be in a similar situation.

Key TEIs

What are the “key” elements?

They include:

• Essential micronutrients that influence ocean productivity: e.g., Fe, Zn, Cu, Co, Ni, Cd.

• Diagnostic tracers of sources and sinks in the modern ocean: e.g., Al, 3He, Mn, Ra isotopes, 15N, Nd isotopes; 234Th, 230Th, 231Pa.

• Chemical species used as proxies to reconstruct past ocean circulation and productivity: e.g., 231Pa, 230Th, 15N of NO3, 13C of DIC, Cd/PO4

3-, Nd isotopes, Ba.

• Contaminants in the present and future ocean: e.g., Pb, Hg.

Need to understand fluxes at four interfacesand four types of internal cycling.

Coupled to study of the capture of information as proxies

Global Strategy and Overarching Goals

GEOTRACES: Program Elements

Enabling Activities Standards and intercalibration Data protocols, management, archiving Modeling Capacity Building

International Polar Year

Ocean Sections Core activity - requires international cooperation Covering regions dominated by major processes National cruises with international collaboration

Process Studies Targeted at processes known to be important Targeted at “anomalies” detected in ocean sections Some will focus on ocean boundaries (e.g., coastal regions) Some will exploit time-series stations

GEOTRACES: Capacity Building

Trace metal - clean sampling technology and methods

Many nations lack infrastructure and expertise for clean sampling

Principal barrier is sampling at sea, not analyses

GEOTRACES offers international assistance in design, construction and use of clean sampling systems

Metals as Essential Micronutients

Nitrogen Cycle Uptake of C, N and PMorel et al., 2003

DataLimited for Fe

Existing deep ocean Fe data

Stations with Fe concentrations at depths > 2000 m in 2003 (taken from GEOTRACES Science Plan 2006)

Fe data is scarce, particularly in the deep ocean, limited understanding of the Fe cycle

DataLimited for Fe

Existing deep ocean Zn data

Stations with Zn concentrations at depths > 2000 mAs of 2009 - compiled by Maeve Lohan

Distribution and cycling of other micronutrients poorly known

Section 3

POLARSTERNJuly-October

2007

Greenland

Siberia

Polarstern ARK XXII-2 Cruise (Rutgers van der Loeff, de Baar)

An IPY Highlight

Data from Klunder, Laan, Middag, de Baar et al.

Significant Fe and Mn supply from Gakkel Ridge

Strategy for Global Ocean Coverage

• International workshops define priorities for each basin

• National committees select research targets based on:National prioritiesAnticipated benefitsResourcesInterests and expertise

• Coordination via international SSC

Strategy for Global Ocean Coverage

• International workshops define priorities for each basin

• National committees select elements based on:National prioritiesAnticipated benefitsResourcesInterests and expertise

• Coordination via international SSC

Global Ocean Coverage

In red: Planned Sections.

In yellow: Completed Sections.

In black: Sections completed as GEOTRACES contribution to the IPY.

Global Ocean Coverage

CompletedGA02: Netherlands (2010/11)GA03: USA (2010/11)GA06: UK (2011)GA10: UK (2010/11)GA11: Germany (2010)GA04: Netherlands and Spain (2013)

Future plansGA01: France (2014-2015)

Global Ocean Coverage

CompletedGI04: Japan (2010) GI02: India (2012)GI03: India (2013)

Future PlansGI01: India (2013)GI05: Australia/France (2015/2016)

Global Ocean CoverageCompletedGP03: Japan (2010)GP13: Aus/NZ (2011)GP18: Japan (2011)GP12: France (2012)GP02: Japan (2012)

Firm PlansGP16: USA (2013)GP07: China-Taipei(2014)

Future plansGP04: CanadaGP06: China-JapanGP08 and GP09: ChinaGP10: Japan (2014)GP11: AustraliaGP15 and GP17: USAGP19: Japan

GEOTRACES Arctic Workshop (May 2-4, 2012 - Vancouver, Canada)

2015 GEOTRACES International Arctic Programme

Proposed tentative cruise tracks:

• Red (US, UK, Russia)• Magenta (Canada)• Yellow (Sweden)• Black (Germany)

Yellow dots denote cross-

over stations to be occupied

by more than one national

program for calibration.

Report available on the GEOTRACES site: http://www.geotraces.org

www.geotraces.org

ipo@geotraces.org

Geotraces@ldeo.columbia.edu

Timeline

Development of GEOTRACES2000 Group discussions at international meetings2001 Fall AGU special session and open meeting2003 International Planning Workshop - Toulouse (Funded by NSF)

SCOR sponsorship and establishment of Planning Group2004 National planning meetings

Science Plan writing starts2006 Science Plan published; SSC forms2007-09 First cruises - IPY and intercalibration2007 Basin planning workshops (Hawaii; Oxford; Goa)

First Model-Data Workshop (Delmenhorst) Data assembly centre starts; COST Action starts

2009 Arctic Basin workshop (Delmenhorst)Second Model-Data Workshop (Paris)

2010 First full GEOTRACESSectionsInternational Project Office (IPO) set up(Toulouse)

Timeliness

Substantial interdisciplinary benefits of disciplinary study of ocean geochemistry

Now 30 years since last global program in marine geochemistry (GEOSECS)

Improved ability to sample the ocean without contamination

Increased sensitivity ofanalytical instrumentation

Advances in modeling permit rates and fluxes to be derived

Overriding Goal: Characterize TEI distributions

• Combine distributions with knowledge of basic processes

• Infer: Sources, sinks, internal cycling

• Multi TEI strategy reveals additional information

• Initial emphasis on sections to characterize distributions

Contamination free sampling systems:Principal GEOTRACES Capacity-Building Effort

• Japan• Netherlands • U.S.A. • New Zealand (2000m) • France (under construction)• Germany (funded)• Canada (expanding) • India (funded)• Australia (under construction)• Taiwan (3000m)• UK (awaiting winch)• China (seeking funding with new ship)