What is an Atmospheric Cap

We’ve talked before about how hot air and cold air interact and lead to thunderstorms, but today we will look at why that temperature difference helps thunderstorms grow. 

What You Need: 

-large glass jar

-small glass cup

-red and blue food coloring

-knife

-plastic wrap

-rubber band

-hot and cold water

-tongs 

What to Do: (you can watch my video demonstration here)

-fill the small cup with hot water and add just a couple drops of red food coloring

-cover the cup with plastic wrap and seal it with a rubber band

-fill the big jar almost full with cold water and a few drops of blue food coloring

-use the tongs to set the small cup inside the large jar and watch what happens

-cut the plastic wrap with the knife while the small cup is still inside the large jar and watch what happens

What is Happening:

We’ve seen before that the hot water is less dense so it rises. We’ve also seen before how air temperature and pressure are connected and how that contributes to thunderstorm development. When the air is bottled up and prevented from mixing with its environment, all that energy builds up until it can finally escape. By that point it’s much more powerful. On big severe weather days, the atmosphere does the same thing. A “cap” develops that traps all that air down here at the ground. Eventually the bottled up air becomes so strong it break through the cap and creates a strong storm.