INTRODUCTIONThis special issue is dedicated to several aspects of state-of-the-art computing for geoscience applications with a focus on subsurface phenomena.The underlying comprehensive numerical models are the basis for predictive simulations of remediation scenarios and recovery processes in subsurface reservoirs. Such models are typically based on continuous Galerkin finite-element methods or cell-centered finite differences and more recently on mixed finite element, finite volume, or mimetic finite differences.The data for such simulations is typically sparse, and is frequently considered non-deterministic. The associated uncertainty of simulation results can be decreased thanks to the improved classic and to the new emerging reservoir characterization tools, which include seismic imaging and sensor technologies. Such methods deliver enormous volumes of data which have to be assimilated with the simulation results. The resulting reservoir characterization-simulation loop presents enormous computational and data challenges.The computational challenges arise from multiscale character and complexity of the numerical models, which require sophisticated nonlinear and linear solver techniques. In spite of recent dramatic increases in computational power there is a constant need to improve existing simulation techniques implemented on state-of-the-art large-scale parallel platforms as well as on commodity clusters. In addition, scalable Grid-based technologies are necessary in order to fully exploit the existing distributed computational and storage resources. Several disciplines still lack the appropriate tools to handle large-scale simulation projects and it is rare to have tools that span multiple and interdisciplinary projects.This special issue is a collection of papers on the above-mentioned aspects of parallel and distributed computing for geoscience applications and includes both the tools as well as the applications perspective. The results demonstrate novel approaches to solutions to the underlying computing and data challenges. Efficient parallel methods for seismic imaging and reservoir simulation are discussed in [1][2][3]. Scalable Grid-oriented solutions to data intense problems arising in the reservoir characterization-simulation loop are proposed and evaluated in [4]. Problems arising in Grid-based simulations of coupled reservoir models are addressed in [2,4]. In addition, the collaborative and interactive steering capabilities are proposed in [2]. Finally, different approaches to software framework
1364EDITORIAL construction are discussed in [2,3]; the common theme is that the underlying framework methodology must be abstract enough to include a variety of applications yet it must keep the overhead to a reasonable minimum in order to offer a competitive edge to a particular application.