701-0475-00L Atmospheric Physics
| Semester | Autumn Semester 2024 |
| Lecturers | U. Lohmann |
| Periodicity | yearly recurring course |
| Language of instruction | German |
| Abstract | This course covers the basics of atmospheric physics, which consist of: cloud and precipitation formation, especially prediction of showers and severe convective storms, and optical phenomena | |||||||||||||||||||||
| Learning objective | Students are able - to explain the mechanisms of convective storm formation using knowledge of thermodynamics and cloud microphysics. - to interpret precipitation radar images - to evaluate the significance of clouds and aerosol particles for artificial weather modification. In the course "Atmospheric Physics", the competencies of process understanding, system understanding and data analysis & interpretation are taught, applied and examined. Measurement methods are taught as well. | |||||||||||||||||||||
| Content | The course starts with introducing selected concepts of thermodynamics for atmospheric processes: The students learn the concept of the thermodynamic equilibrium and derive the Clausius-Clayperon equation from the first law of thermodynamics. This equation is central for the phase transitions in clouds. Students also learn to use thermodynamic charts (tephigrams) and to identify cloud base, cloud top, available convective energy in radiosonde ascents. Atmospheric mixing processes are introduced as a basis for fog formation. The concept of an air parcel is used to understand convection. Aerosol particles are introduced in terms of their physical properties and their role in cloud formation based on Köhler theory. Thereafter cloud microphysical processes including ice nucleation are discussed. With these basics, the different forms of precipitation (convective vs. stratiform) are discussed and how they can be identified in radar images. Students will also learn under which conditions severe convective storms (especially supercells with tornados) can form. The concepts are applied to understand and judge the validity of different proposed artificial weather modification ideas. | |||||||||||||||||||||
| Lecture notes | Powerpoint slides and chapters from the textbook will be made available on moodle: https://moodle-app2.let.ethz.ch/course/view.php?id=22731 | |||||||||||||||||||||
| Literature | Lohmann, U., Lüönd, F. and Mahrt, F., An Introduction to Clouds: From the Microscale to Climate, Cambridge Univ. Press, 391 pp., 2016. An electronic version of this book can be obtained via the ETH library. pdf-files of the revised book will be provided on moodle on a chapter-by-chapter basis. | |||||||||||||||||||||
| Prerequisites / Notice | We offer a lab tour, in which we demonstrate how some of the processes discussed in the lectures are measured with instruments. There is a additional tutorial right after each lecture to give you the chance to ask further questions and discuss the exercises. The participation is recommended but voluntary. | |||||||||||||||||||||
Competencies |
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