Development of mpi_EPIC model for global agroecosystem modeling

The mpi_EPIC model employs a parallel design developed for intensive modeling.The model dramatically accelerated global high-resolution agroecosystem modeling.A case study of global simulation for a crop was conducted for productivity analysis. Agroecosystem models that can incorporate management practices and quantify environmental effects are necessary to assess sustainability-associated food and bioenergy production across spatial scales. However, most agroecosystem models are designed for a plot scale. Tremendous computational capacity on simulations and datasets is needed when large scales of high-resolution spatial simulations are conducted. We used the message passing interface (MPI) parallel technique and developed a master-slave scheme for an agroecosystem model, EPIC on global food and bioenergy studies. Simulation performance was further enhanced by applying the Vampir framework. On a Linux-based supercomputer, Cray XT7 Titan, we used 2048 cores and successfully shortened the running time from days to 30min for a global 30years of modeling of a bioenergy crop at the resolution of half-degree (62,482 grids) with the message passing interface based EPIC (mpi_EPIC). The results illustrate that mpi_EPIC using parallel design can balance simulation workloads and facilitate large-scale, high-resolution analyses of agricultural production systems, management alternatives and environmental effects.