An introduction to the program Bob Anderson Co-chair International GEOTRACES SSC

Mission GEOTRACES guiding mission “To identify processes and quantify fluxes that control the distributions of key trace elements and isotopes (TEIs) in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions”

Key TEIs What are the “key” elements? They include: Those acting as micronutrients to control ocean productivity and ecosystems Those tracing modern processes in the ocean Contaminants in the present and future ocean Chemical species used as proxies to reconstruct past climate

Anticipated Benefits What are the anticipated benefits? They include: 1)Identify sources and sinks and quantify internal cycling of essential micronutrients (e.g., Fe, Zn, Co, Cd, Cu). 2)Calibrate geochemical tracers used to reconstruct past ocean conditions (e.g., circulation, chemistry, biological productivity, carbon fluxes) for more reliable applications. 3)Quantify groundwater supply of dissolved materials. 4)Improve predictions of the transport and fate of contaminants.

Need to understand fluxes at four interfaces and four types of internal cycling. Coupled to study of the capture of information as proxies Strategy and Overarching Goals

Timeline Development of GEOTRACES 2000Group discussions at international meetings 2001Fall AGU special session and open meeting 2003International Planning Workshop - Toulouse (Funded by NSF) SCOR sponsorship and establishment of Planning Group 2004National planning meetings Science Plan writing starts 2006Science Plan published; SSC forms First cruises - IPY and intercalibration 2007 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) 2010First full GEOTRACES Sections International 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 of analytical instrumentation Advances in modeling permit rates and fluxes to be derived

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)

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

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

Enabling Activities Intercalibration Two US-led cruises in 2008 and 2009 International measurement intercalibration (Cutter, Bruland, Sherrell) Data management Hosted at British Oceanographic Data Centre Data Manager - Dr. Ed Mawji (Measures, Schiltzer) Modelling to plan cruises and benefit from data Two international data-model workshops held in Germany and France (Schlitzer, Dutay)

Metals as Essential Micronutients Nitrogen CycleUptake of C, N and P Morel 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 m As of compiled by Maeve Lohan Distribution and cycling of other micronutrients poorly known

AtlanticNitrate Distribution and cycling of the macronutrients Nitrate data from WOCE A16 section One of 24 such sections in Atlantic alone

Pre-GEOTRACES Atlantic Section

Al traces source of Fe Fe distribution reflects biological uptake and regeneration Measures et al., 2008 Aluminum traces supply of dust, a source of iron

AtlanticNitrate Distribution and cycling of the macronutrients Nitrate data from WOCE A16 section One of 24 such sections in Atlantic alone

Atlantic Fe Fe (nmol/kg) …compared to the micronutrients Data show richness of features in Fe distribution (Measures et al. 2008)

Deep Ocean Fe Gradients Boyd and Ellwood, Nature Geoscience, 2010 As recently as a decade ago it was thought that [Fe] in the deep ocean was uniform everywhere. Deep ocean has rich spatial features: Gradients opposite of macronutrients (N, P) Reflects unique sources and internal cycling

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

International Polar Year Marion Dufresne during Bonus-Goodhope IPY cruise

Proposed Atlantic Sections

Iron and Mn indicate hydrothermal vents on Mid Ocean Ridge Unpublished data of Maarten Klunder, Patrick Laan, Rob Middag and Hein de Baar Fe Mn Al AfricaAntarctica

Strategy for Global Ocean Coverage International workshops define priorities for each basin National committees select elements based on: National priorities Anticipated benefits Resources Interests 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 Completed GA02: Netherlands (2010/11) GA03: USA (2010/11) GA06: UK (2011) GA10: UK (2010/11) GA11: Germany (2010) GA04: Netherlands and Spain (2013) Future plans GA01: France ( )

Global Ocean Coverage Completed GI04: Japan (2010) GI02: India (2012) GI03: India (2013) Future Plans GI01: India (2013) GI05: Australia/France (2015/2016)

Global Ocean Coverage Completed GP03: Japan (2010) GP13: Aus/NZ (2011) GP18: Japan (2011) GP12: France (2012) GP02: Japan (2012) Firm Plans GP16: USA (2013) GP07: China-Taipei (2014) Future plans GP04: Canada GP06: China-Japan GP08 and GP09: China GP10: Japan (2014) GP11: Australia GP15 and GP17: USA GP19: Japan

-European co-ordination: An ESF COST Action was funding networking and meetings across Europe ( Involvement of 18 European countries (Belgium, Croatia, Finland, France, Germany, Greece, Iceland, Ireland, Israel, Italy, Netherlands, Norway, Poland, Portugal, Spain, Sweden,Switzerland, United Kingdom) One focus is on co-ordination and organization of a Mediterranean Sea cruise (June-August 2013) -Arctic co-ordination: Co-ordination meeting in Delmenhorst, Germany Second co-ordination meeting (29 September - 1 October, 2010), Washington, D.C. -Third co-ordination meeting in Vancouver, Canada Transnational GEOTRACES Activities

GEOTRACES Arctic Workshop (May 2-4, 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:

Western Pacific Coordination Report of the GEOTRACES Pacific Planning Workshop, 2007

Links to other programmes Need to understand fluxes at four interfaces and four types of internal cycling. Coupled to study of the capture of information a proxies

Links to other programmes Need to understand fluxes at four interfaces and four types of internal cycling. Coupled to study of the capture of information a proxies SOLAS InterRidge IMBER CLIVAR PAGES