Table of Contents
Table of Contents
- Formation of rains
- Clouds appear white – Why?
- The interrelation between Winds and Rains
- Monsoon rains in India
- Summary
- What’s Next?
In the previous segment of the chapter ‘Natural Resources,’ we learnt about wind. In this segment, let us get to know what forms rain.
How is rain formed?
We know from our previous segment that heating of air causes it to expand and rise. We also know that air contains moisture or water vapour. Moisture in the air is in the gaseous state and it slowly rises above along with the air molecules. As the moisture rises higher, it gets cooler and at a certain point, the water vapour condenses into a water droplet on the surface called the nucleus. The nucleus is nothing else but dust particles present in the atmosphere. These nuclei are also called as cloud seeds which will be surrounded by the water droplet.
Several such nuclei come together to form clouds. When billions of water droplets form a cloud, at a point the cloud becomes heavy as it has a lot of water in it. At this point, the cloud cannot hold the water anymore and these droplets begin to fall as rain on the earth.
Why do clouds appear white?
The sun is the main contributing factor as to why clouds often appear to be white. We know that clouds are composed of tiny water droplets. When the sunlight is scattered by the water droplets, all wavelengths of light scatter almost equally. Since there are millions of water droplets in the atmosphere, sunlight is scattered into various colours that combine to form the colour white, which gives clouds a white colour.
