Meteorology is perhaps the most dynamic of all the earth sciences. In no other sphere do events routinely unfold so quickly, with so great a potential impact on humans. Some of the most striking atmospheric disturbances (such as tornadoes) can take place over time scales on the order of minutes--but nevertheless have permanent consequences. Wind speeds of several hundred kilometers per hour accompany the most violent storms, and large-scale extreme events with attendant widespread destruction are common. Furthermore, even the most mundane of atmospheric phenomena influence our lives on a daily basis (for instance, the beauty of blue skies or red sunsets, rain, the daily cycle of temperature). Atmospheric processes, despite their immediacy on a personal level and their importance in human affairs on a larger level, are not readily understood by most people. This is probably not surprising, given that the atmosphere consists primarily of invisible gases, along with suspended, frequently microscopic particles, water droplets, and ice crystals. In this book, our overriding goal is to bridge the gap between abstract explanatory processes and the expression of those processes in everyday events. We have written the book so that students with little or no science background will be able to build a nonmathematical understanding of the atmosphere. That said, we do not propose to abandon the foundations of physical science. We know from our own teaching experience that physical laws and principles can be mastered by students of widely varying backgrounds. In addition, we believe one of meteorology's great advantages is that reasoning from fundamental principles explains so much of the field. Compared to some other disciplines, this is one in which there is an enormous payoff for mastering a relatively small number of basic ideas. Finally, our experience is that students are always excited to learn the "why" of things, and to do so gives real meaning to "what" and "where." For us, therefore, the idea of forsaking explanation in favor of a purely descriptive approach has no appeal whatsoever. Rather, we propose merely to replace mathematical proof (corroboration by formal argument) with qualitative reasoning and appeal to everyday occurrences. As the title implies, the goal remains understanding atmospheric behavior. Understanding Weather and Climateis a college-level text intended for both science majors and non-majors taking their first course in atmospheric science. We have attempted to write a text that is informative, timely, engaging to students and easily used by professors. Distinguishing Features Scientific Literacy and Currency.We have emphasized scientific literacy throughout the book. This emphasis gives students an opportunity to build a deeper understanding about the building blocks of atmospheric science and serves as tacit instruction regarding the workings of all the sciences. For instance, in Chapter 2 we cover the molecular changes that occur when radiation is absorbed or emitted, items that are often considered a "given" in introductory texts. In Chapter 3 these basic ideas are used to help build student understanding of why individual gases radiate and absorb particular wavelengths of radiation and illustrate how processes operating at a subatomic level can manifest themselves at global scales. An emphasis on scientific literacy can be effectively implemented only if it is accompanied by careful attention to currency. We believe that two kinds of currency are required in a text: an integration of current events as they relate to the topic at hand, and an integration of currentscientific thinking.For instance, the reader will find discussion of both recent hurricane activity and the most recent theories regarding the mechanisms that generate severe storms. Scientific literacy also calls for attention to language--after allAguado, Edward is the author of 'Understanding Weather and Climate', published 2003 under ISBN 9780131015821 and ISBN 0131015826.