Numerical modeling of conserved atmospheric fields is critical to weather prediction and climate simulation. Atmospheric dynamics often distort these fields into long filamentary structures that are difficult to model, because the extreme aspect ratios of the filaments present a wide range of spatial scales that need to be resolved. A method of dealing with these differing spatial scales is to use a dynamic adaptive grid (DAG) technique, which continuously moves grid points in response to changes in the tracer field to give higher resolution where small spatial scales are prominent. The Multidimensional Positive Definite Advection Transport Algorithm (MPDATA) of Smolarkiewicz is used to solve the advection equation on a moving grid. As the number of grid points increases, instabilities in MPDATA with an adaptive grid occur due to violation of the CFL condition. Analysis of the problem leads to a method of limiting grid point movement to maintain stability.

This is an overview of the development of adaptive techniques for atmospheric modeling. Written in an educational style, it functions as a starting point for readers interested in adaptive modeling, in atmospheric sciences and beyond. Coverage includes paradigms of adaptive techniques, such as error estimation and adaptation criteria. Mesh generation methods are presented for triangular/tetrahedral and quadrilateral/hexahedral meshes, with a special section on initial meshes for the sphere.

Although GIS provides powerful functionality for spatial analysis, data overlay and storage, these spatially oriented systems lack the ability to represent temporal dynamics, which is a major impediment to its use in surface modeling. However, rapid development of computing technology in recent years has made real-time spatial analysis and real-time data visualization become realizable. Based on newly developed methods, Surface Modeling: High Accuracy and High Speed Methods explores solutions to big-error and slow-efficiency problems, two critical challenges that have long plagued those working in with geographical information system (GIS) and computer-aided design (CAD). By developing high accuracy and high speed methods for surface modeling, the book builds a bridge between the mathematical-oriented theory of surface modeling and the user-oriented application where the user is actually able to retrieve information on the method itself. The author examines a novel method of high accuracy surface modeling (HASM) in terms of the fundamental theorem of surfaces. He then analyzes the coefficient matrix and develops an adaptive method of HASM (HASM-AM), a multi-grade method of HASM (HASM-MG), and an adjustment method of HASM (HASM-AD). He uses numerical tests and real world studies to demonstrate that HASM-AM, HASM-MG, and HASM-AD have highly accelerated computational speed, especially for simulations with huge computational work. Building on this, the book discusses a HASM-based method for dynamic simulation (HASM-FDS), and then applies HASM methods to simulate terrains, climate change, ecosystem change, land cover, and soil properties. It demonstrates HASM's potential for simulating population distribution, human carrying capacity, ecosystem services, ecological diversity, change detection, and wind velocity. The book concludes with a discussion of the problems that exist in surface modeling on a global level and evaluates possible solutions to these problems.

In various branches of fluid mechanics, our understanding is inhibited by the presence of turbulence. Although many experimental and theoretical studies have significantly helped to increase our physical understanding, a comp- hensive and predictive theory of turbulent flows has not yet been established. Therefore, the prediction of turbulent flow relies heavily on simulation stra- gies. The development of reliable methods for turbulent flow computation will have a significant impact on a variety of technological advancements. These range from aircraft and car design, to turbomachinery, combustors, and process engineering. Moreover, simulation approaches are important in materials - sign, prediction of biologically relevant flows, and also significantly contribute to the understanding of environmental processes including weather and climate forecasting. The material that is compiled in this book presents a coherent account of contemporary computational approaches for turbulent flows. It aims to p- vide the reader with information about the current state of the art as well as to stimulate directions for future research and development. The book puts part- ular emphasis on computational methods for incompressible and compressible turbulent flows as well as on methods for analysing and quantifying nume- cal errors in turbulent flow computations. In addition, it presents turbulence modelling approaches in the context of large eddy simulation, and unfolds the challenges in the field of simulations for multiphase flows and computational fluid dynamics (CFD) of engineering flows in complex geometries. Apart from reviewing main research developments, new material is also included in many of the chapters.