In some countries, it rains all the time, which plays a major role in the growth of grass and crops. As we can see that Ireland is such a green country because of heavy rain there. Rain is essential for life and the main source of water would which we cannot survive. Definitely we need rain for the growing of crops and grass and also all the lakes and rivers need it. In this topic, we will come to know about the water cycle, about the different types of rainfall as well as clouds.
Water Cycle
Water moves from the rivers and streams all the way up to the sky and there forming clouds. Also, water moves from sea to sky. All these are the part of the water cycle or hydrological cycle. This cycle makes water move from sea to sky and sky to river. Without it, we cannot have streams, lakes not even sea. Therefore without this cycle, it will not be possible for humans or animals to survive at all. Here are some stages of this cycle:
- The cycle begins at sea, where water is warmed by the sun. This causes the evaporation of seawater. Thus seawater turns to water vapor and then steam. This vapor rises as hot air tend to be light.
- With the height, water vapor becomes cooler. This cooling causes the water vapor to condense as it cannot store water droplets.
- When the vapor condenses, clouds are formed. This cloud receives more and more vapor until it cannot store any more. After saturation of the cloud precipitation starts.
- Based on the temperature, precipitation has many forms. Thus it can include rain, hailstones, sleet or snow.
- This rain flows into rivers and streams and these rivers and streams bring the water back to the sea where the cycle begins again.
Types of Rainfall
There are three main types of rainfall that occur frequently and depend on a variety of factors.
Relief Rainfall
This type of rainfall is common in places with mountains and sea. Relief rainfall frequently occurs near mountains beside the sea. The moisture-laden wind blows in from the sea because the wind meets a high mountain and hence it is forced to rise upwards. At the height, it is cooled and then the cloud is formed.
This saturated cloud with water vapor begins to precipitate on the side of the mountain facing the sea. This front side of the mountain is called the windward side.
The cloud mostly precipitates on the windward side of the mountain. Meanwhile, the cloud meets the other side, which is called the leeward side. Since the cloud has already lost most of its moisture so it rains very little there.
This makes leeward sides of a mountain very little rains. There is a much more moist climate on the windward sides of slopes. On the other hand, there is a more dry, sheltered climate on the leeward side. This rainfall is common in Hawaii, Sierra Nevada, and the Andes.
Convectional Rainfall
Suppose we are enjoying the rays of sunshine and suddenly, the sky gets darker with the grey cloud. Without any warning the heavens open and it begins to rain, with a thundery feel. This is the convectional rain. It occurs frequently on hot days usually giving cumulus cloud and thundery showers.
The sun heats the ground which causes the air to warm and become very hot. Then the air rises upwards and becomes cool. Then it condenses to form cumulus cloud.
When this cloud is saturated, it begins to precipitate giving heavy and thundery showers. Due to this, we get thundershowers on a hot day, as the Sun warms the air and it rises, cools and begins to rain.
Frontal Rainfall
This rainfall occurs when a warm, tropical air mass comes in contact with a cold, polar air mass. It is very common in Britain and Ireland. Because the air is in the warm front, then it rises over the cold front. The air is cooled and so condenses to form a stratus cloud. Thus when the stratus cloud becomes saturated, it begins to precipitate.
Solved Question on Types of Rain
Q: What is Acid Rain?
Ans: Rain with high levels of acid i.e. with a low pH value is called acid rain. It is caused by the release of Sulphur Dioxide and Nitrogen Oxides into the air. These chemicals often come from factories and power stations. It can be harmful to plants and animals.
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