16/07/ ASM Montreal Biogeochemical Outbreak 1 Modelling of Biogeochemical Cycles and Ecosystems in the Arctic Ocean Participants: Nadja Steiner (DFO/EC), Dieter Wolf-Gladrow (AWI), Diane Lavoie (DFO),David Plummer (EC), Yvonnick Le Clainche (U. Rimouski), Clara Deal (IARC/UAF), Leif Anderson (U Gotenborg), Mat Reagan (Berkeley Lab)

16/07/ ASM Montreal Biogeochemical Outbreak 2 1. Science questions that can be best answered with coupled Arctic regional climate models; science questions missing from existing plans. How will cycling of elements (C,N,P,Ca,S,O,Fe) change in the next decades? What is the impact of climate-relevant gases produced in the ocean on Arctic climate? Strengths of biogeochemical feedbacks. Time scales: current/preindustrial, future (next decades), past (glacial-interglacial and beyond) ‏

16/07/ ASM Montreal Biogeochemical Outbreak 3 Cycling of nutrients and organic matter in the current system: What are the major processes? Rates? Coherent quantitative description? How much food is available for higher trophic levels? (fish, mammals), Occurance of HABs... Future changes due to temperature change, retreat/vanishing of summer sea ice, ocean acidification, coastal erosion, melting of permafrost,...: What is the impact on cycling of nutrients and organic matter? Change in marine ecosystems (primary production, species assemblage,..., impact on higher trophic levels)?

16/07/ ASM Montreal Biogeochemical Outbreak 4 Biogeochemical feedbacks Sulfur: DMS -> Cloud Condensation Nuclei (CCN) -> -> radiation -> temperature ->... Impact of ice algae on melting of sea ice (Zeebe et al., 1996) ‏ Impact of phytoplankton blooms on mixed layer temperature (Manizza et al., 2005) ‏ (Biogeo)chemistry in sea ice: discovery of ikaite (CaCO 3 * H 2 O), consequences for bromine oxid (BrO) ‏ formation and ozone depletion events (ODEs) in polar marine boundary layer, mercury sink, carbon flux within sea-ice, marine carbonate system

16/07/ ASM Montreal Biogeochemical Outbreak 5 Biogeochemical feedbacks Instability of gashydrates -> CH 4 release from sediments -> oxidation of CH 4 in the water column ->... (bacterial request of copper: Scott Elliot) ‏ Impact of black carbon on albedo and melting of sea ice Input of nutrients (including metals) and various forms of carbon: transformations in the river-sea transition zone. Dissolution of CaCO 3 in surface sediments (ocean acidification)

16/07/ ASM Montreal Biogeochemical Outbreak 6 Biogeochemical feedbacks Instability of gashydrates -> CH 4 release from sediments -> oxidation of CH 4 in the water column ->... (bacterial request of copper: Scott Elliot) ‏ Impact of black carbon on albedo and melting of sea ice Input of nutrients (including metals) and various forms of carbon: transformations in the river-sea transition zone. Dissolution of CaCO 3 in surface sediments (ocean acidification)

16/07/ ASM Montreal Biogeochemical Outbreak 7 The inclusion of a biogeochemical process into coupled models makes sense only when the corresponding feedback implemented, e.g. when, for example, atmospheric DMS and its transformation is included. What do atmospheric models represent?

16/07/ ASM Montreal Biogeochemical Outbreak 8 2. Existing/planned modelling and model validation efforts to address the above AWI: Polarstern expeditions (central Arctic, Fram Strait) Various research activities in the Lena Delta and Laptev Sea (river input, coastal erosion, sedimentation) ‏ Needed: historical data review, archive > develop modified sampling strategies

16/07/ ASM Montreal Biogeochemical Outbreak 9 3. Reasonable boundaries for the 'Arctic System' for respective research areas; What are the opportunities and limitations due to a limited Arctic model domain? Hydrological cycle under global change requires larger domain (or time dependent boundary conditions). The same applies on somewhat longer time scale to inflow of Atlantic and Pacific water. Opportunities: better representation of small scale processes

16/07/ ASM Montreal Biogeochemical Outbreak How are observations incorporated into model development and how can the link be improved? Parameterizations of various processes based on observations. Data assimilation/inverse models to improve parameterizations. Involve modellers in development of sampling strategies (What is needed? What is possible?) ‏ Involve observers in model development - improve process understanding => Two way communication !!! Modellers need to tell funding agencies they need observations (seasonal data, fill local gaps, archive historical data) ‏

16/07/ ASM Montreal Biogeochemical Outbreak Would regional modelling efforts benefit from an international, centralized method for sharing model output for intercomparison and for sharing validation data and validation code/methods? Yes! Open access of model output and observations parallel to publication of articles (collaborative ?). Compare: open access to CO 2 observations (CDIAC). Data center for validation and intercomparison: provide constraints for data submission

16/07/ ASM Montreal Biogeochemical Outbreak What interactions are there between regional modelling and global modelling in your field of research? Would projects benefit from a community-coordinated program for obtaining data from and sharing model output with a global modelling community? Need interaction for time dependent boundary conditions... Compexity of ecosystem models - global versus regioal CCCma - close collaboration between global GCM and RCM, forecast.... for ecosystem only starting. other groups similar? CICE, many groups collaborating, development of parameterisations

16/07/ ASM Montreal Biogeochemical Outbreak What plans are in action for including emerging modules into existing regional arctic models? IARC/UAF/LANL: Regional ecosystem, ice algae, nutrients in CICE (sea-ice internal), DMS within ice DFO/EC: Earth system model developments, ecosystem models in ocean models, 1-D: marine sulphur cycle (DMS), ice algae Berkely Lab/ LANL: coupling a gas hydrate/methane model in POP

16/07/ ASM Montreal Biogeochemical Outbreak What human dimension modelling is being done in conjunction with physical modelling?

16/07/ ASM Montreal Biogeochemical Outbreak What are possible interface strategies for collaboration between natural-science modelling and research on adaptation and human living conditions? Importance of river input ( Influx Changes with land use changes, permafrost melting) ‏ Ocean acidification Fisheries Harmful algal blooms (HABs),...

16/07/ ASM Montreal Biogeochemical Outbreak What level of interaction between components is desirable? Depending on feedbacks (examples: Atmospheric deposition Gas exchange with retreating ice cover, ice ecosystem, river inflow...) ‏

16/07/ ASM Montreal Biogeochemical Outbreak What is the benefit of interactive coupling on the complete system? Inclusion of feedbacks. Continuous simulations

16/07/ ASM Montreal Biogeochemical Outbreak Which other components should your component be coupled to? Answer depends on questions/time scales. Start: atmosphere, ocean, ice, pelagic ecosystem (carbonate system, nutrients, plankton) ‏ ecosystem in the ice climatically active gases... On longer time scales: add sediment module

16/07/ ASM Montreal Biogeochemical Outbreak On what time scale is interactive coupling/one-way coupling useful? General answer: depends on the feedback(s) under investigation Limitation due to boundary conditions in regional models. What is required: list of possible feedbacks, their strengths and their characteristic time constants.

16/07/ ASM Montreal Biogeochemical Outbreak 20 Coupling of ecosystem models with circulation models The coupling of ecosystem models to circulation models is relative easy because the various compartments of ecosystem models (nutrients, DIC, TA, phytoplankton, zooplankton) can be treated similar to other passive tracers, however, with specific sources and sinks. Thus the implementation should be possible in less than one month. For gases (CO 2, DMS,...) air-sea gas-exchange has to be added.

16/07/ ASM Montreal Biogeochemical Outbreak 21 The End Thanks for your attention

16/07/ ASM Montreal Biogeochemical Outbreak 22 Discussion

16/07/ ASM Montreal Biogeochemical Outbreak 23 Steiner & Denman 2008

16/07/ ASM Montreal Biogeochemical Outbreak 24 Steiner & Denman 2008

16/07/ ASM Montreal Biogeochemical Outbreak 25 Steiner & Denman 2008

16/07/ ASM Montreal Biogeochemical Outbreak 26 Ikaite

16/07/ ASM Montreal Biogeochemical Outbreak 27 Loose et al. 2009

16/07/ ASM Montreal Biogeochemical Outbreak 28 Type of questions Global: cycles of elements Regional: climate-relevant gases, food production (fisheries, higher trophic levels) ‏ Local: variations in ecosystems Fundamental: fast changes Carmack & Wassmann, 2006

16/07/ ASM Montreal Biogeochemical Outbreak 29 Manizza et al. 2005

16/07/ ASM Montreal Biogeochemical Outbreak 30 Organic Carbon Budget: Arctic Ocean vs. Global Ocean Stein & Macdonald (2004)‏ Quantity Arctic Ocean Global Ocean Primary production > 330 (1%) River input (POC) River input (DOC) 24.5 (10%) Eolian input Coastal erosion 5.4 ? units: all values in 10 6 t C year -1

16/07/ ASM Montreal Biogeochemical Outbreak 31 Manizza et al. 2005

16/07/ ASM Montreal Biogeochemical Outbreak 32 Manizza et al. 2008

16/07/ ASM Montreal Biogeochemical Outbreak 33 Zeebe et al. 1996

16/07/ ASM Montreal Biogeochemical Outbreak 34 Dieckmann et al. 2008

16/07/ ASM Montreal Biogeochemical Outbreak 35 Morin et al Atmos. Chem. Phys., 8, 7317–7324,

16/07/ ASM Montreal Biogeochemical Outbreak 36 Zhao et al. 2008

16/07/ ASM Montreal Biogeochemical Outbreak 37 Ice sheets model: Mass balance & sea level Ice-ocean interaction Permafrost Biogeochemistry/Ecosystem marine biogeochemical cycles (based on RECOM)‏ continental weathering input sediment module Isotope modules: 13 C, 18 O, 30 Si ice cores, marine sediments, … Programme: PACES Earth System Model … expansion of the COSMOS ECHAM5 OASIS MPI-OM HAMOCC5 Chemistry Isotope Proxy Models Ice Sheets Model Modules (following COSMOS)‏