Today was very rainy, with wind whipping tree branches around, dark, rolling clouds, and torrents of rain so hard you couldn’t see as you drove down the quickly flooding streets. Luckily, it quickly calmed down, but it was after I remembered the days of reading The Magic School Bus stories about precipitation. Most people know the water cycle and all that jazz, but I wanted to go more in-depth about rain and rain clouds!
First off, I just want to clarify something that I used to say all the time. “It smells like its going to rain!” You have probably said it yourself a couple of times. Well, rain smells like water. What does water smell like? Not much! The smell is actually from plants. This quote from another site summarizes it quite well: “Plants release oils that enter the soil and blend with the other earthy odors. These odors are released into the air when the relative humidity at ground level exceeds 75 percent. Moist humid air will transmit odors far better than dry air. In these moist humid conditions we notice these odors more readily. And since rain is so often connected with moist humid air, we tend to associate one with the other.” This actually makes much more sense than smelling rain. One small myth busted for rain, one giant step for chemistry!
Another thing you should know is that all raindrops do not look like this: In fact, this is not even one of the more common shapes! The chart below might help.
I didn’t know that before, but I definitely know I won’t forget it now!
Now that we have established correct raindrop shapes, we need to know cloud shapes!
- Cirrus – thin and wispy clouds that are very high up, made of tiny pieces of ice, occur the day before rain or snow, cirrus means “tuft or curl of hair.”
- Cumulus – large, fluffy clouds, cumulus meaning “pile” or “heap.” Cumulus clouds can turn into clouds that bring thunderstorms, called Cumulonimbus clouds.
- Stratus – dark layers that hang low, stratus means “to spread out.” Stratus clouds can bring rain, snow, or fog.
Clouds are formed when water warms up and changes into water vapor. As it rises higher in the sky, the vapor cools down and turns back into tiny drops of liquid. Tiny pieces of dust floating in the air help make the clouds more visible and the water droplets form around the dust. As more water is changed into water vapor, and then back into tiny water droplets, the cloud grows. When enough water droplets have gathered together in a cloud, their weight drags them out of the cloud, and they drop to the ground, making rain!
Here are two weather related jokes I found:
- What kind of precipitation does a king like best? (Answer: Hail!)
- What is it called when it rains chickens and ducks? (Answer: Fowl weather.)
So Ta Ta for now and hope to see your chemical reaction soon!