Using record player demonstrations as analog models for geophysical fluids

Abstract:

All celestial bodies, including stars, planets, satellites, and asteroids, rotate. The influence of rotation on the fluid layers in these bodies plays an important and diverse role, affecting many processes including oceanic and atmospheric circulation at the surface and magnetic field generation occurring in the interior. To better understand these large-scale processes, record players and containers of water are used as analog models to demonstrate the basic interplay between rotation and fluid motions. To contrast between rotating and non-rotating fluid motions, coffee creamer and food coloring are used as fluid tracers to provide a hands-on method of understanding the influence of rotation on the shapes of the planets, weather patterns, and the alignment of magnetic fields with rotational axes. Such simple demonstrations have been successfully employed for children in public outreach events and for adults in graduate level fluid dynamics courses.