Always Take the Weather With You

The last theme of the year, called Always Take the Weather With You, was about weather; we worked out what weather actually is and how it works.

We poured water onto the concrete to make a puddle, and drew a chalk line around it.

When we cam out an hour later, we found the water had disappeared.  In fact, all that was left was the chalk line.  The water could not soak into concrete, but it could rise up into the air if the sun warmed it enough.  We thought that is what had happened.  Scientists call this phenomena evaporation.

Observing changes in the weather is sometimes difficult to do,  so we made models to help us we see the general idea in the classroom.  In this scientific model, water  is the atmosphere, shaving foam is the cloud, and water droplets that are in the cloud are represented by blue dye.  

Can you see what happened after you had waited for a while? The 'rain' is starting the fall through the 'cloud'.

For this scientific model, we had to use an aquarium full of tap water for the atmosphere.  We coloured hot water with red dye and poured some in a glass jar which we carefully lowered into the water using a string lassoed around the jar.  At the same time, we placed ice cubes which were coloured with blue dye on the surface of the water.  Then we sat back to observe.  We could see the red water rising, and the blue water sinking.  This models exactly what happens in a thunderstorm.  As hot air rises and cold air sinks, they swirl together which  results in a thunderstorm.