project		modeling
intro goals challenges background methane fluxes the methane barrier AOM hydro-acoustics microbiology methods modeling database work packages working areas publications			University of Utrecht (UU) are responsible for tackling the modelling of AOM and methane turnover in marine sediments as part of WP3. UU will take the initiative in developing a diagenetic reactive transport model of bulk anaerobic oxidation of methane in marginal sediments, implementing experimental data obtained by partners. The model will be used to quantify methane turnover and the principal physical and biogeochemical controls of methane flux from marine sediments to the ocean. Initially, in Phase (I) we employ a zero-dimensional model to investigate parameter sensitivity of AOM. Since AOM occurs with less energy-yielding electron acceptors than aerobic oxidation and denitrification, thermodynamic constraints are included. Subsequently, in Phase (II), the Biogeochemical Reaction Network Simulator (BRNS) will be employed to model bulk AOM. The BRNS provides a reactive transport simulation environment in which transport processes are interfaced with relevant biogeochemical reactions (Regnier et al., 2002). The BRNS consists of three key elements: (1) a MAPLE pre-processor, containing an automated procedure for model code generation (Automatic Code Generator); (2) a numerical engine, combining standard routines for solving transport equations, and sets of coupled nonlinear process equations generated by the MAPLE pre-processor; and (3) a Web-distributed Knowledge Base (KB). The Automatic Code Generator translates user-specified information (size of the problem, variables, reaction stoichiometries, kinetic expressions, boundary conditions, etc) plus information extracted from the Knowledge Base into Fortran code. In this approach, it is at the level of an easily accessible open resource, the KB, that process-based theoretical and experimental advances are incorporated in the modeling process. Literature: Boetius, A., Ravenschlag, K., Schubert, C. J., Rickert, D., Widdel, F., Gieseke, A., Amann, R., Jorgensen, B. B., Witte, U., and Pfannkuche, O. 2000 A marine microbial consortium apparently mediating anaerobic oxidation of methane. Nature 407, 623-626. Regnier, P., O\'Kane, J. P., Steefel, C. I., Vanderborght, P. A. 2002 Modeling complex multi-component reactive-transport systems: towards a simulation environment based on the concept of a Knowledge Base. Applied Mathematical Modelling 26, 913-927. back to top