This text prepares students by laying a solid foundation in the application of physical, chemical, and mathematical principles to a broad range of atmospheric phenomena. Students are introduced to fundamental concepts and applications of atmospheric thermodynamics, radiative transfer, atmospheric chemistry, cloud microphysics, atmospheric dynamics, and the atmospheric boundary layer.
- The atmosphere consists mostly of dry air - mostly molecular nitrogen (78%), molecular oxygen (21%), and Argon (0.9%) - and highly variable amounts of water vapor (from parts per million in air to a few percent). Now we will consider gases and particles in the atmosphere at trace levels. The most abundant of the trace gases in the global atmosphere is carbon dioxide (~400 parts per million), but there are thousands of trace gases with fractions much less than a few parts per million.
- Clouds and precipitation are integral to weather and can be difficult to forecast accurately. Clouds come in different sizes and shapes that depend on atmospheric motions, their composition, which can be liquid water, ice, or both, and the temperature. While clouds and precipitation are being formed and dissipated over half the globe at any time, their behavior is driven by processes that are occurring on the microscale, where water molecules and small particles collide.
- In this lesson we will look at solar radiation and its changes over time. Radiation is just another form of energy and can be readily converted into other forms, especially thermal energy, which is sometimes called "heat." In this lesson, we will use the word "radiation" to mean all electromagnetic waves, including ultraviolet, visible, and infrared. We will introduce some unfamiliar terms like "radiance" and "irradiance" and will be careful with our language to prevent confusion.
- Now that you are familiar with the principles of atmospheric radiation, we can apply them to help us better understand weather and climate. Climate is related to weather, but the concepts used in predicting climate are very different from those used to predict weather.
- This lesson introduces you to the math and mathematical concepts that will be required to understand and quantify atmospheric kinematics, which is the description of atmospheric motion; and atmospheric dynamics, which is an accounting of the forces causing the atmospheric motions that lead to weather. Weather is really just the motion of air in the horizontal and the vertical and the consequences of that motion.
- The study of kinematics provides a physical and quantitative description of our atmospheric motion, while the study of dynamics provides the physical and quantitative cause-and-effect for this motion. This chapter discusses kinematics.
- This text has been compartmentalized into eleven chapters to aid your learning and to grow your analytical skills. But in the atmosphere, the fundamentals of atmospheric science work together to create the atmosphere that we observe. In this lesson, you will work to draw on your understanding of the atmosphere to explain an atmospheric observation that you have chosen.