This book grew out of an introductory course that I was invited to teach on a number of occasions to senior and graduate level students at the University of Kid. I have cherished these opportunities in part because I was never required to conduct examinations or give grades. For the students, however, my good fortune presented special problems that induced my sympathy: in addition to having to contend with a foreign language, they would eventually have to confront an examiner with his own ideas about what they should have learned. Although I always left a copy of my lecture notes with this person, they were too sketchy to be of much use. The present book is an attempt to solve some of these problems. The content is intended to be as broad as possible within the limitations of an introductory one-semester course. It aims at providing an insightful view of present understanding, emphasizing the methods and the history of their development. In particular I have tried to expose the power of intuitive reasoning - the nature of tensor invariants, the usefulness of dimensional analysis, and the relevance of scales of physical quantities in the inference of relationships. I know of no other subject that has benefited more from these important tools, which seem to be widely neglected in the teaching of more fundamental disciplines.

The rather excessive public preoccupation of the immediate past with what has been labeled the 'environmental crisis' is now fortunately being replaced by a more sus tained and rational concern with pollution problems by public administrators, engineers, and scientists. It is to be expected that members of the engineering profes sion will in the future widely be called upon to design disposal systems for gaseous and liquid wastes which meet strict pollution control regulations and to advise on possible improvements to existing systems of this kind. The engineering decisions involved will have to be based on reasonably accurate quantitative predictions of the effects of pollutants introduced into the atmosphere, ocean, lakes and rivers. A key input for such calculations comes from the theory of turbulent diffusion, which enables the prediction of the concentrations in which pollutants may be found in the neighborhood of a release duct, such as a chimney or a sewage outfall. Indeed the role of diffusion theory in pollution prediction may be likened to the role of applied mechanics (,strength of materials') in the design of structures for adequate strength. At least a certain group of engineers will have to be proficient in applying this particular branch of science to practical problems. At present, training in the theory of turbulent diffusion is available only at the gra duate level and then only in a very few places.

The study of turbulence in the atmosphere has seen considerable progress in the last decade. To put it briefly: boundary-layer meteorology, the branch of atmospheric science that concentrates on turbulence in the lower atmosphere, has moved from the surface layer into the boundary layer itself. The progress has been made on all fronts: theoretical, numerical and observational. On the other hand, air pollution modeling has not seen such a rapid evolution. It has not benefited as much as it should have from the increasing knowledge in the field of atmospheric turbulence. Air pollution modeling is still in many ways based on observations and theories of the surface layer only. This book aims to bring the reader up to date on recent advances in boundary-layer meteorology and to pave the path for applications in air pollution dispersion problems. The text originates from the material presented during a short course on Atmospheric Turbulence and Air Pollution Modeling held in The Hague during September 1981. This course was sponsored and organized by the Royal Netherlands Meteorological Institute, xi xii PREFACE to which both editors are affiliated. The Netherlands Government Ministry of Health and Environmental Protection and the Council of Europe also gave support.

Originally published in 1955 Atmospheric Turbulence examines dynamic meteorology and the fundamental part it plays in the overall science of meteorology. The book examines the theory of atmospheric turbulence as a more mathematically developed area than largescale motions of the atmosphere and examines its significance in economic, military and industrial spheres. The book focuses on the effect and importance of atmospheric turbulence, not only to meteorologists, but the designers of large aircraft. The book addresses the effects of turbulence and the properties of the atmosphere that can be found closer to the ground. This book will be of interest to atmospheric physicists and meteorologists.

Based on his over forty years of research and teaching, John C. Wyngaard's textbook is an excellent up-to-date introduction to turbulence in the atmosphere and in engineering flows for advanced students, and a reference work for researchers in the atmospheric sciences. Part I introduces the concepts and equations of turbulence. It includes a rigorous introduction to the principal types of numerical modeling of turbulent flows. Part II describes turbulence in the atmospheric boundary layer. Part III covers the foundations of the statistical representation of turbulence and includes illustrative examples of stochastic problems that can be solved analytically. The book treats atmospheric and engineering turbulence in a unified way, gives clear explanation of the fundamental concepts of modeling turbulence, and has an up-to-date treatment of turbulence in the atmospheric boundary layer. Student exercises are included at the ends of chapters, and worked solutions are available online for use by course instructors.

What do the movements of molecules and the migration of humans have in common? How does the functionality of our brain tissue resemble the flow of traffic in New York City? How can understanding the spread of ideas, rumors, and languages help us tackle the spread a pandemic? This book provides an illuminating look into these seemingly disparate topics by exploring and expertly communicating the fundamental laws that govern the spreading and diffusion of objects. A collection of leading scientists in disciplines as diverse as epidemiology, linguistics, mathematics, and physics discuss various spreading phenomena relevant to their own fields, revealing astonishing similarities and correlations between the objects of study—be they people, particles, or pandemics. This updated and expanded second edition of an award-winning book introduces timely coverage of a subject with the greatest societal impact in recent memory—the global fight against COVID-19. Winner of the 2019 Literature Prize of the German Chemical Industry Fund and brainchild of the international and long-running Diffusion Fundamentals conference series, this book targets an interdisciplinary readership, featuring an introductory chapter that sets the stage for the topics discussed throughout. Each chapter provides ample opportunity to whet the appetite of those readers seeking a more in-depth treatment, making the book also useful as supplementary reading in appropriate courses dealing with complex systems, mass transfer, and network theory.

Since its discovery in early 1900, turbulence has been an interesting and complex area of study. Written by international experts, Air Pollution and Turbulence: Modeling and Applications presents advanced techniques for modeling turbulence, with a special focus on air pollution applications, including pollutant dispersion and inverse problems. The