Challenges in developing an interdisciplinary teaching material on effects related to the Earth’s rotation

Abstract

The increasing public attention attracted by environmental issues requires the understanding of the physics behind large scale motions of the atmosphere and the oceans. It is therefore necessary to extend the scope of secondary education to the physical principles behind these phenomena related to the Earth’s rotation. The main message to convey is the fascinating effect that the importance of the Coriolis deflection increases with extension in space. The communication of size making such a difference requires quantitative considerations, whereas high school treatment is scarce and only provides a qualitative explanation of the Coriolis deflection. To bridge this gap, we have developed secondary level teaching material on the physical background of large-scale environmental processes and made it available on the internet for interested students and teachers. Aimed at regular secondary school students, it requires no further knowledge beyond the very basics of mechanics. The material consists of a core study and several extensions. The core study only uses elementary formulae and is easily followed by as independent learner or completed in three teaching periods in class. It begins with simple hands-on experiments from which students can derive the expression of the Coriolis acceleration. Students can also use data from their own experiments or everyday life observations to obtain a numerical measure of the strength of the Coriolis effect. Through the three sections, the material proceeds from small scales, where the Coriolis effect is practically negligible, to planetary scales, where the effect inevitably becomes dominant. As an illustration of the difference between the large and small scales, it also reveals why a video pretending to demonstrate the different rotation of plughole vortices around the Equator must be faked. The material has been developed in permanent contact with students, the paper also shows steps of improvement based on the feedback received from them.