I was the departmental coordinator for the Canada-wide Science Festival, which was held at McGill this year. Geared at high school students it is also a great outreach opportunity for university departments to provide information to prospective students.
Things got quite crowded during the day with the weather in a tank set-up being a magnet for students and teachers alike.
A can of ice is placed in a rotating water tank. The temperature gradient together with the rotation creates flows (visualized with food coloring) that are strikingly similar to atmospheric patterns in the mid-latitudes, where the temperature gradient is caused by the warm regions near the equator and the cold poles.
There was also a display about how melting sea ice does not contribute to sea-level rise, but melting glaciers do. We also demonstrated the sea ice albedo effect with a lamp and thermometers placed near black and white paper.