Quantitative Skills > Teaching Resources > Activities > Kohler Curves

Kohler Curves

Swarn Gill, California University of Pennsylvania
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This activity has benefited from input from a review and suggestion process as a part of an activity development workshop.

This activity has benefited from input from faculty educators beyond the author through a review and suggestion process as a part of an activity development workshop. Workshop participants were asked to peruse activities submitted by others in their disciplinary group prior to the workshop. The groups then convened early in the workshop to discuss the materials and make suggestions for improvements. To learn more about this review process, see http://serc.carleton.edu/quantskills/review_processes.html#2004.


This page first made public: Oct 23, 2009

Summary


In this assignment students investigate the process of cloud droplet nucleation by analyzing the importance of supersaturation, radius of curvature, CCN solute mass and temperature. Students will be produce 3 plots using the spreadsheet program of their choice. The first plot is used to test their understanding of the reading. The second plot is used to help them determine the importance of supersaturation and solute mass, and the third to help them determine the importance of supersaturation and temperature. The final questions let them apply calculus skills to the problem. Questions are a mixture of short and long answer questions.

Learning Goals

Context for Use

This assignment is designed for use in a cloud physics/physical meteorology course. Within cloud physics it belongs to the area of drop nucleation.

Description and Teaching Materials

Assignment (Microsoft Word 30kB Jul17 04)
Partial Solution (Microsoft Word 344kB Jul17 04)

Teaching Notes and Tips

This is assignment could easily include a part that asks them to draw the solute and curvature terms seperately so that they can perhaps better see how the Kohler curve is a combination of these two. I have left it out here because it is covered in the reading and the assignment is quite lengthy already.

More information on reading material that is useful for the professor and possibly the students, as well as information on the background knowledge and context for this assignment in a course and curriculum can be found in the following file: Instructor notes - context (Microsoft Word 25kB Jul17 04)

Some information on the common problems I have seen students have with this assignment can be found in the following file: Instructor notes - problems (Microsoft Word 21kB Jul17 04)

Assessment

The assignment should be handed in either electronically or on paper (I prefer paper) to the instructor with just the figures attached to their answers to the questions. I also ask students to send me their excel file by e-mail. This is a way in which I can give partial credit by possibly seeing where they went wrong if their graphs are incorrect. The weight given to the graphs and the conceptual answers are at the teachers discretion. Since it is a quantitative assignment and since most of the time will be spent on the excel program I like to give greater rewards to the graphs created, although ultimately the concepts are the most important.

References and Resources

Rogers, R. R., M. K. Yau, 1989. A Short Course in Cloud Physics, 3rd Ed. Pergamon Press. 293 pp.

Young, K. C., 1993. Microphysical Processes in Clouds. Oxford Press. 427 pp.

Wallace, J. M., P.V. Hobbs, 1977. Atmospheric Science: An Introductory Survey. Academic Press. 467 pp.

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