10th Conference On Mountain Meteorology

"If you are an amateur weather geek, disaster wonk, or budding student of earth sciences, you will want to read this book." —Seattle Times In 2011, there were fourteen natural calamities that each destroyed over a billion dollars’ worth of property in the United States alone. In 2012, Hurricane Sandy ravaged the East Coast and major earthquakes struck in Italy, the Philippines, Iran, and Afghanistan. In the first half of 2013, the awful drumbeat continued—a monster supertornado struck Moore, Oklahoma; a powerful earthquake shook Sichuan, China; a cyclone ravaged Queensland, Australia; massive floods inundated Jakarta, Indonesia; and the largest wildfire ever engulfed a large part of Colorado. Despite these events, we still behave as if natural disasters are outliers. Why else would we continue to build new communities near active volcanoes, on tectonically active faults, on flood plains, and in areas routinely lashed by vicious storms? A famous historian once observed that "civilization exists by geologic consent, subject to change without notice." In the pages of this unique book, leading geologist Susan W. Kieffer provides a primer on most types of natural disasters: earthquakes, tsunamis, volcanoes, landslides, hurricanes, cyclones, and tornadoes. By taking us behind the scenes of the underlying geology that causes them, she shows why natural disasters are more common than we realize, and that their impact on us will increase as our growing population crowds us into ever more vulnerable areas. Kieffer describes how natural disasters result from "changes in state" in a geologic system, much as when water turns to steam. By understanding what causes these changes of state, we can begin to understand the dynamics of natural disasters. In the book’s concluding chapter, Kieffer outlines how we might better prepare for, and in some cases prevent, future disasters. She also calls for the creation of an organization, something akin to the Centers for Disease Control and Prevention but focused on pending natural disasters.

Mountainous regions occupy a significant fraction of the Earth's continents and are characterized by specific meteorological phenomena operating on a wide range of scales. Being a home to large human populations, the impact of mountains on weather and hydrology has significant practical consequences. Mountains modulate the climate and create micro-climates, induce different types of thermally and dynamically driven circulations, generate atmospheric waves of various scales (known as mountain waves), and affect the boundary layer characteristics and the dispersion of pollutants. At the local scale, strong downslope winds linked with mountain waves (such as the Foehn and Bora) can cause severe damage. Mountain wave breaking in the high atmosphere is a source of Clear Air Turbulence, and lee wave rotors are a major near-surface aviation hazard. Mountains also act to block strongly stratified air layers, leading to the formation of valley cold air-pools (with implications for road safety, pollution, crop damage, etc.) and gap flows. Presently, neither the fine-scale structure of orographic precipitation nor the initiation of deep convection by mountainous terrain can be resolved adequately by regional-to global-scale models, requiring appropriate downscaling or parameterization. Additionally, the shortest mountain waves need to be parameterized in global weather and climate prediction models, because they exert a drag on the atmosphere. This drag not only decelerates the global atmospheric circulation, but also affects temperatures in the polar stratosphere, which control ozone depletion. It is likely that both mountain wave drag and orographic precipitation lead to non-trivial feedbacks in climate change scenarios. Measurement campaigns such as MAP, T-REX, Materhorn, COLPEX and i-Box provided a wealth of mountain meteorology field data, which is only starting to be explored. Recent advances in computing power allow numerical simulations of unprecedented resolution, e.g. LES modelling of rotors, mountain wave turbulence, and boundary layers in mountainous regions. This will lead to important advances in understanding these phenomena, as well as mixing and pollutant dispersion over complex terrain, or the onset and breakdown of cold air pools. On the other hand, recent analyses of global circulation biases point towards missing drag, especially in the southern hemisphere, which may be due to processes currently neglected in parameterizations. A better understanding of flow over orography is also crucial for a better management of wind power and a more effective use of data assimilation over complex terrain. This Research Topic includes contributions that aim to shed light on a number of these issues, using theory, numerical modelling, field measurements, and laboratory experiments.

This book provides readers with a broad understanding of the fundamental principles driving atmospheric flow over complex terrain and provides historical context for recent developments and future direction for researchers and forecasters. The topics in this book are expanded from those presented at the Mountain Weather Workshop, which took place in Whistler, British Columbia, Canada, August 5-8, 2008. The inspiration for the workshop came from the American Meteorological Society (AMS) Mountain Meteorology Committee and was designed to bridge the gap between the research and forecasting communities by providing a forum for extended discussion and joint education. For academic researchers, this book provides some insight into issues important to the forecasting community. For the forecasting community, this book provides training on fundamentals of atmospheric processes over mountainous regions, which are notoriously difficult to predict. The book also helps to provide a better understanding of current research and forecast challenges, including the latest contributions and advancements to the field. The book begins with an overview of mountain weather and forecasting chal- lenges specific to complex terrain, followed by chapters that focus on diurnal mountain/valley flows that develop under calm conditions and dynamically-driven winds under strong forcing. The focus then shifts to other phenomena specific to mountain regions: Alpine foehn, boundary layer and air quality issues, orographic precipitation processes, and microphysics parameterizations. Having covered the major physical processes, the book shifts to observation and modelling techniques used in mountain regions, including model configuration and parameterizations such as turbulence, and model applications in operational forecasting. The book concludes with a discussion of the current state of research and forecasting in complex terrain, including a vision of how to bridge the gap in the future.