Clouds – core and basic types https://fotisedu.com/clouds-core-and-basic-types/
Amazing facts about clouds https://fotisedu.com/amazing-facts-about-clouds/
What are clouds?
They are the visible aggregate of minute particles of water and/or ice. They form when water vapor condenses.
They can grow very tall or appear flat as a pancake.
They are typically white in colour but also appear in different shades of grey or in brilliant yellow, orange or red.
They can weigh tens of millions of tons yet float in the atmosphere.
Formation of clouds
There are two ingredients needed for clouds to become visible – water and nuclei.
Nuclei
In one form or another water is always present in the atmosphere. However, water molecules in the atmosphere are too small to bond together for the formation of cloud droplets.
They need a “flatter” surface, an object with a radius of at least one micrometer on which they can form a bond. Those objects are called nuclei.
Nuclei are minute solid and liquid particles found in abundance. They consist of such things as smoke particles from fires or volcanoes, ocean spray or tiny specks of wind-blown soil.
These nuclei are hygroscopic meaning they attract water molecules.
Called “cloud condensation nuclei”, these water molecule attracting particles are about 1/100th the size of a cloud droplet upon which water condenses.
Therefore, every cloud droplet has a speck of dirt, dust or salt crystal at its core. But, even with a condensation nuclei, the cloud droplet is essentially made up of pure water.
Temperature’s role
But having water attracting nuclei is not enough for a cloud to form as the air temperature needs to be below the saturation point.
Called the dew point temperature, the point of saturation is where evaporation equals condensation.
Therefore, a cloud results when a block of air (called a parcel) containing water vapor has cooled below the point of saturation.
Air can reach the point of saturation in a number of ways. The most common way is through lifting of air from the surface up into the atmosphere.
For more information https://climatekids.nasa.gov/cloud-formation/
PRACTICE QUESTIONS
QUES 1 . The two ingredients needed to form clouds aloft are:
(a) Instability and lifting
(b) Lifting and saturated air
(c) Wind shear and Lifting
(d) Air with a high dewpoint and instability
Ans: (b)
