Understanding Weather and Climate (Hardcover)

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 Climate is 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.

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 current scientific 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 all, precision of language is an important distinguishing characteristic of science, one that sets it apart from other intellectual activities. With that in mind, we have tried to avoid some common statements of dubious accuracy, such as "warm air is able to hold more water vapor than cold air."

Media. A fundamental feature of this book is the integration of the classic textbook model with the emerging areas of instructional technology. These nontraditional resources are delivered through the CD provided with the book and via the Internet. The software on the accompanying CD consists of several components. Perhaps most fundamental to our approach, the CD features nine computer tutorials covering basic principles of atmospheric science. The software modules have undergone considerable testing and have been used successfully by thousands of students. They rely heavily on three-dimensional diagrams and animations to present material not easily visualized using conventional media. In choosing topics for the modules, we have emphasized material that is both difficult to master and has the potential to benefit from computer technology. We made no attempt to cover every chapter in the modules.

The software modules follow a tutorial style, with explanations and new vocabulary introduced incrementally, building on what was presented earlier in the modules and what was presented in the text. The tutorials are best used as a supplement to assigned readings. Students and professors will notice that the book and the tutorials are linked. First, the tutorials are described in Media Enrichment sections found at the end of every chapter. In addition, CD icons in the book margins (example shown to the right) indicate that the topic under discussion is covered in a tutorial as well. A numeric subtitle indicates the section of the tutorial covering that topic. For example, the icon to the right indicates tutorial 2, section 2, subsection 1. We advise that you first view a tutorial in its entirety. If additional review is needed, you can use the section number to move directly to the section under discussion. The tutorials are also linked back to the text. The icon shown at right (taken from a tutorial) is used to locate places where the book provides more detailed or background information about the topic at hand.

In addition to the tutorials, the CD for the third edition of the book contains other useful resources, including:

• Weather in Motion movies, depicting events and phenomena discussed in the text. Examples include a satellite movie showing clouds and temperature across the globe, three-dimensional simulations of thunderstorm development, and animations depicting variations in Earth's orbit. Like the tutorials, each movie is described in the Media Enrichment section at the end of every chapter.
• Weather Images, providing additional illustration of weather phenomena. These include photographs, satellite images, and computer diagrams complementing the text. Each is described in a Media Enrichment section.
• Media Library resources, consisting of additional images, movies, and animations. These are intended for self-guided browsing by the student and are therefore not explicitly mentioned in the text. A short description of each is found on the CD.
• Interactive Exercises, which are short activities produced by Gregory J. Carbone of the University of South Carolina. These modules cover important topics, such as hurricanes and Earth-Sun relations, and are described in the Media Enrichment sections. Expanded versions of the modules are presented with The Lab Manual for Atmospheric Science by Gregory J. Carbone, which is available at a discount when packaged with this book.

The CD-ROM for this third edition of the text has been improved dramatically, with a more logical and easy-to-use design and navigational structure. In addition, the software has been moved outside of a browser environment. This move provides many advantages, foremost among them the fact that now no installation is required (beyond QuickTime) in order to use the CD. This should greatly ease the use of the CD in a lab situation and will relieve users from troublesome issues of browser versioning.

We should emphasize that although the computer resources are tightly integrated with the book, a computer-equipped lab is not required. All of the resources have been designed for stand-alone use, without supervision by an instructor or TA. Extensive knowledge of computers is not assumed for either instructors or students. We must also emphasize that the computer applications described above are intended to supplement rather than replace more traditional teaching tools. In fact, the book is written so that instructors who choose not to use computers at all can assign the text without needing to supply any "missing" information or alternate activities.Instructors may choose to annotate and return exercises by computer or may prefer to simply grade from screen copy. (Of course, print functions are available as well for those requiring paper copy.)

Instructor Flexibility. During the writing process, we have enjoyed interacting with many of our colleagues who teach courses in weather and climate on a regular basis. It was especially interesting to see how little consensus exists regarding topic order (truth be told, the authors of this book don't agree on the optimal sequence). With this in mind, we tried to minimize the degree to which individual chapters depend on material presented earlier. Thus, instructors who prefer a chapter order different than the one we ultimately chose will not be disadvantaged. In this third edition we are using a novel approach to the sequencing of chapters on atmospheric moisture and pressure. The introductory chapter on pressure now resides ahead of the chapters on moisture. This facilitates student learning with regard to vapor pressure, saturation, and the importance of surface convergence into low pressure regions as a mechanism for cloud formation. Chapters on the distribution of pressure and wind patterns follow moisture, as they have in previous editions.

Emphasis on Forecasting. In addition to a comprehensive chapter on the topic, this text contains numerous examples of how physical principles are employed in weather forecasting. We have included several discussions of the use of thermodynamic diagrams in weather forecasting and analysis. These charts are extremely valuable but not immediately comprehensible to most students. To alleviate this problem,`we introduce thermodynamic diagrams in a sequential fashion. That is, their use for plotting vertical temperature profiles is presented in the chapter on temperature. We expand upon this in the chapter on atmospheric moisture to show how various measures of humidity can also be determined with the aid of the charts. Thus, instructors can teach their students how to use these diagrams without inundating them with excessive detail all at once.

Readability. In contrast to the more formal scientific style used in many science textbooks, we have chosen to adopt more casual prose. Our goal is to present the material in language that is clear, readable, and friendly to the student reader. We employ frequent headings and subheadings to help students follow discussions and identify the most important ideas in each chapter. As a rule, we keep technical language to a minimum.

Focus on Learning. The chapters offer a number of study aids:

• Key Terms. Key terms in each chapter are printed in boldface when first introduced. Most are also listed at the end of each chapter, along with the page number on which each first appears. All key terms are defined in the glossary at the end of the book.
• Focus on the Environment Boxes. These boxes highlight environmental issues as they relate to the study of the atmosphere.
• Physical Principles Boxes. More mathematical in nature than the rest of the text, these boxes accommodate students who have a more quantitative interest in the topic. An understanding of the material in these boxes is not essential to an understanding of the material presented in the body of the text.
• Special Interest Boxes. These boxes highlight interesting topics related to the discussion at hand.
• Forecasting Boxes. These describe how the principles discussed in the chapter can be used in forecasting and often include simple "rules of thumb" that help students make their own forecasts.
• Chapter Summary. Each chapter concludes with a chapter summary that highlights the main points in the chapter.
• Review Questions. At the end of each chapter, you will find a list of questions about the subject of that chapter. These review questions test reading comprehension and can be answered from information presented in the chapter. We have greatly expanded this section for the third edition.
• Quantitative Problems. The Understanding Weather and Climate Web site features quantitative exercises to accompany each chapter. If you choose to work these problems, the computer will grade them and provide you with immediate feedback.
• Critical Thinking Questions. For the third edition we have added these questions to the end of each chapter. These questions require students to use the thought process and material presented in the chapter to work out answers relevant to real-world questions.
• Problems and Exercises. Another feature new to the third edition, these questions encourage students to work out solutions to numerical questions to gain a better understanding of chapter material.
• Useful Web Sites. This is a unique feature we have included to the current edition, describing relevant and interesting Web sites with valuable information or current data at the end of each chapter.
• Software Tutorial Icons. Throughout the book, the software icons (see the list above) will appear where the topic under discussion is reviewed in the tutorial modules that accompany the book. We suggest that you use the tutorial if you are having trouble understanding this topic using the text alone.