4B20.16 • Convection: Baroclinic Instability

Location: Cabinet 4

Concept Conveyed:

• Baroclinic instability is formed when there is a pressure gradient across a fluid. In this case, the gradient is created by a difference of fluid temperatures.
• This demo is an analogue to the Earth where polar winds interact with warmer winds at lower latitudes creating baroclinic instabilities in our atmosphere.

Instructions / Notes:

• Start the rotation of the rotary platform with the can of ice at the center. Place the 1000 g mass over the can to keep it from floating.
• Allow the water to spin up for about a minute before adding dye.
• Drop red dye representing warmer water into the water around the bowl near the rim of the glass, and drop blue dye representing cooler water around the can of ice.

Demo Staff:

• Set demo to 33 RPM before leaving room to allow the water time to uniformly rotate before professor uses the demo.
• Provide both blue and red food coloring.
• Fill cans with ice from the ice trays in the upstairs freezer. Do not freeze water in the cans or they will explode as the water expands.

Photo Shows the Demonstration used by the University of Texas at Austin

Last updated on April 27, 2026