What Makes Clouds and Why Do They Change Their Shapes?
Clouds consist of droplets of water or tiny crystals of ice that float in the air. Clouds form when warm air, containing moisture evaporated from the Earth’s surface, rises into the sky and begins to cool. As the air cools, some of the vapor it contains condenses into tiny cloud droplets. As the clouds float through the cold air above the Earth, they often hit areas where the air is warmer. The warm air evaporates some of the cloud’s moisture, leaving the cloud with a new shape. Winds blowing against the clouds also affect the clouds’ shapes.
Clouds play an important role in the energy balance of Earth. They cool the earth by reflecting sunlight back out to space. How else do you think astronauts see where they are going? More importantly, clouds replenish our water supply. It’s a never-ending cycle but one that keeps the earth balanced.
You can tell a lot by looking at a cloud’s shape, size and texture. Clouds are put into categories according to their shape, how high they are in the sky, their size, how fast and in what direction they are moving, etc. The three different types of clouds are high clouds (because they are high in the sky), medium clouds and low clouds (just over 10,000 feet high or 3 km.)
High Clouds are curly looking and made of ice.
Cirrus: The ice-crystal cloud is a feathery white cloud that is the highest in the sky. It has a wispy looking tail that streaks across the sky and is called a fallstreak.
Cirrostratus: A milky sheet of ice-crystal cloud that spreads across the sky. It’s easy to name because it’s the only cloud type that creates a ring or halo around the sun or moon. There’s an old proverb that goes, “A ring around the sun or moon brings rain or snow upon you soon.”
Cirrocumulus: This very rare cloud type appears in clusters of small, white, roundish patches.
Low clouds usually look like huge puffs of cotton. These are the clouds that you can see animals and other objects in.
Cumulus: The fair weather cloud. Each cloud looks like a cauliflower.
Stratocumulus: A layer of cloud that can sometimes block the sun. It looks like a thick white blanket of stretched out cotton.
Stratus: A fog that isn’t that far above the ground. In the morning, wind can push very low fog into stratus clouds.
Rain Clouds are usually stretched out or layered and cover the entire sky. When rain falls from them, they’re called nimbostratus clouds.
Nimbostratus: The dark, rain carrying cloud of bad weather. It is to blame for most of the winter rains and some of the summer ones. It covers the sky and blocks the sun. You have to fly in a plane through the cloud to realize how deep and solid this cloud can be.
Cumulonimbus: The cloud that produces showers and thunderstorms. The rain comes and goes with these clouds. Big Cumulonimbus clouds have lumps that look like cows’ udders, called mamma. In the US if you see a mamma this might mean a possible tornado.
Did you know?
.Clouds fly higher during the day than during the night.
.Pink mother-of-pearl clouds can be found very high (about 80,000 ft or 24 kms.) These clouds are very thin and can usually be seen before sunrise or after sunset.
.The clouds are lit by the Sun, which is below the horizon.
.The winds inside cumulonimbus clouds can reach a speed of 124 miles per hour (201 kms) – about as fast as most express trains.
.Sunbeams that shine down through clouds are called crepuscular rays.