Rain

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What is Rain?

Rain is droplets of water in the form of liquid which are condensed from water vapour present in the atmosphere and fall down on the ground under gravity when they become heavy. It is the major component of the water cycle process and helps in depositing fresh water on the Earth which is essential for living organisms for survival, producing electricity via hydroelectric power plants and irrigating crops. 

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How Rain is Formed?

Here, we will describe the water cycle through the formation of clouds. 


Water Cycle

When the Sun shines on water on Earth’s surface, the heat of the Sun warms water turning into invisible gas called water vapour. This process of water changing into vapours is called Evaporation. Gas or vapour is lighter than liquid, therefore, it rises up in the sky. Further, it moves away from the Earth’s surface, cooler the temperature gets that turns these vapours into tiny water droplets and this process is called Condensation (opposite of evaporation). Clouds are made up of these tiny water droplets that grow with more water vapours. When water droplets stick to one another, they grow in size and continue to grow till becoming too heavy and fall down as rain or water droplets. Every single droplet that reaches the ground is made up of 1 million original tiny water droplets. This is about the rain formation and these rain drops fall into Earth’s surface and again the Sun plays its role in evaporating this water. The whole process is repeated again and is called Water cycle. Water moves from ground to the sky and it is available to plants, animals, people and other living organisms on Earth to survive.


How are Clouds Formed?

If you get a question like this, it is easier to answer. Clouds are composed of water droplets or ice crystals which are so small and light in weight and are able to be up in the air. This collection of the water and ice into the sky takes place with the help of various steps described in the following:


1. Evaporation

It is the process where some of the liquid water from lakes, rivers and ocean turns into vapour and travels in the atmosphere, with the help of sunlight. The air rises in the atmosphere and gets cooler and under less pressure, it is unable to hold much water so the vapour turns into small water droplets or ice crystals to form a cloud.


2. Condensation

The dust and pollen particles present in the topmost air help in condensation where water vapours condense into water droplets . Condensation nuclei is a term used to describe the dust, pollen or other particles that assist in forming clouds and in the process of rain.


3. Formation of Clouds in Different Ways

  • Some clouds form when air warms up near the Earth’s surface and rises. The heat by sunshine helps in heating the ground and air just above it that starts to rise and form clouds.

  • Some clouds known as lenticular and stratus clouds are formed when wind is blown into the sides of mountain range or terrain and it is forced upward to move higher in the atmosphere. This aids in forming clouds.

  • Some clouds form when the air is forced upward at low pressure areas. This process leads to the formation of all types of clouds including altocumulus, cirrocumulus, altostratus, cirrocumulus and stratus clouds.


Importance of Rain

  • Plants grow with the help of rain showers. No plant will be able to grow without water from rain.

  • Rain is the major component of the water cycle that helps in depositing most of the freshwater on the Earth. 

  • It supports many types of ecosystems and helps in survival.

  • It provides water for hydroelectric plants to generate electricity.

  • It is very helpful for crops to grow as it is a means of crop irrigation on the large fields.

  • It helps in sustaining water level in the ground.

  • Humans make use of the rain water to store and later use it for bathing, cooking, cleaning and drinking. It is called rain harvesting. This process helps in reducing water bills as it provides an alternative supply of water during restrictions and also maintains a healthy and clean garden. There are various filtering options to clean up rain water for direct usage.

  • Rain helps in cooling the atmosphere and helps in reducing the intense temperature of the Earth. Therefore, it is a great relief when it rains during the Summer season.

  • It helps in humidifying the air and replenishing the water table.

  • It helps in generating healthy negative ions.

  • It redistributes the fresh water via water cycle.

  • We can enjoy the beauty of rain when it is just drizzling.

  • It is one of the most important natural phenomena that makes life possible on Earth as agriculture and forest depend on rain which are ultimately the basic requirements for humans. Thus, it helps in generating food as well as supplying water.

FAQ (Frequently Asked Questions)

1. What Plays an Important Role in the Formation of Rain?

Sun is the major source of energy which plays an important role in the rain formation by the process of evaporation. When rays of sunlight hit a lake or sea, the water rises up in the form of vapours and condenses up in the air as the temperature is colder. This is known as condensation. The water particles are really colder and join together to form clouds full of small droplets. These drops grow bigger and bigger and when these are heavy, they fall out of the cloud in the form of rain.

2. What is the Water Cycle?

Water cycle is the process which is responsible to a great extent that answers ‘How does Rain Occur’. It is a hydrological cycle that involves regular circulation of water in various states of matter. It takes place in the following manner:

  • Water gets evaporated in the form of water vapour i.e. it changes from liquid to gaseous state.

  • Water is absorbed back into the earth’s atmosphere from plants, other living organisms and trees.

  • Sublimation occurs where ice and snow gets converted into gas without entering into the liquid state.

  • Formation of clouds occurs as water is converted back into a liquid state.

  • Water in different forms, dust, pollen and other particles in the atmosphere facilitate the formation of clouds through various movements.

  • Precipitation falls in the form of rain, snow, drizzle etc., and the cycle continues.

This is how rain occurs and now you can explain all the factors and phenomenon what causes rain.