Do you know why clouds and rain form in our atmosphere?
Near the surface of the earth, the air is warm and moist. The warm air has a tendency to rise-up because of its lighter weight. It rises up to a particular height, condenses into the water-droplets and forms clouds.
Clouds grow heavier and heavier accumulating the water droplets. As this process continues, clouds are unable to hold the weight of the water-droplets further. As a result, these droplets start falling from the sky in the form of rain.
Near the surface of the earth
The air is warm and moist.
(water is in the form of vapors)
At a certain height in the atmosphere
The air cools and condenses.
( water is in the forms of droplets)
and form clouds.
Before discussing more on the process of the formation of clouds and rain we need to define some key factors.
The formation of clouds and rain: All Related Factors
Conversion of water from liquid to vapors from water bodies.
Conversion of water from liquid to vapors from plants, trees, and forests.
Conversion of water from vapor to liquid.
The amount of water vapor in the atmosphere.
Deposition of moisture as water-droplets on cooler surfaces such as plants leaves, grass, and stones.
When the air containing a large amount of water vapor condenses near to the earth’s surface on minute dust particles, it is called fog.
smoke mixed with fog is called smog.
Deposition of moisture as water-droplets on cooler surfaces below the freezing point is called frost. So we can say it is the frozen dew.
Clouds: Process of formation
The processes of vaporization and condensation of ‘water’ cause the phenomenon of the Water Cycle as well as the formation of clouds.
The water from the water bodies vaporizes and converts into vapors and reaches into the atmosphere. In the troposphere temperature decreases as the height increases.
That’s why at some height vapors cool and condense into water droplets and even minute particles of ice. These droplets are visible as clouds.
Types of clouds
There are mainly four types of clouds.
Short, detached, feather-like white clouds formed at an altitude of 7-12 km.
Cotton wool-like clouds formed at an altitude of 2-5 km.
Low level, white or grey colored clouds covering the full sky and causing rain.
Dark, dense and multilevel clouds, causing rain along with thunder and lightening are called nimbus.
Rain: Process of formation
In the clouds, the water vapors continue joining together due to the continuous condensation process. The water droplets start growing large and heavy, the air becomes incapable of holding them. It starts dropping to the earth’s surface as rain, snow or sleet.
Types of rainfall:
There are mainly three types of rainfalls.
warm air rises up -> expands and cool down at a particular height -> condensation takes place with the formation of clouds -> rainfall starts.
This sort of rainfall is called conventional rainfall. It is very common in the summer season.
Saturated air with a large amount of water vapor -> meets mountains -> mountains force it to rise up -> air expands and cools down due to gain in height -> condensation takes place and it starts raining.
This sort of rainfall is called orographic rainfall. Windward slope of the mountain receives more amount of rainfall than compared to the leeward slope.
warm air mixed with water vapors -> meet cold, polar air -> a front develops due to two different air-currents -> warm and cold air do not mix but warm air rises on top of the cold air -> warm air rises and gain height, it cools and condenses -> rainfall starts.
This type of rainfall is called frontal rainfall. It is very common in the north of Europe.
Are you ready now to answer some of the very common questions related to the clouds and rain? Let’s have fun. You can check the answer at any time by clicking on the question.
Questions & Answers:
Answer: Yes, of course.
As the conversion of water takes place from liquid to vapor and then from vapor to liquid. This conversion of the water is the physical process, not the chemical one. Hence, the formation of clouds and rain is a physical process.
Answer: Like other objects, tiny particles of the water present in the clouds also reflect the sunlight. This gives the clouds different colors.
Clouds can be seen as having many different colors like white, grey, brown and black. Orange and yellow colored clouds can also be seen often at the time of sunrise and sunset. The color of the clouds depends upon the color of sunlight they are reflecting at that particular moment.
White color:- When the water vapors equally scatter all colors of light. Then the color of the clouds is white. That is why normally clouds look white.
Grey, Brown and Black color:- The clouds become thick and dense due to the presence of more water vapors and ice crystals. They become so dense that the sunlight from above can not pass through them. The sky in the background also can not be visible. The color of the cloud base becomes grey or black at that moment. That is why thick clouds have a greyish or blackish presence.
Yellow, reddish and orange color:- At the time of sunrise and sunset the light has to travel a longer distance into our environment to reach the earth’s surface. The colors other than red and orange get scattered because of their low wavelength. That is why the sun appears reddish of orangish.
The same principle is applied to the colors of the clouds at that time. Hence they appear having red or orange colors.
There are different types of precipitation. As we know that the precipitation occurs when water droplets or ice crystals become too heavy to hold by the clouds.
All form of precipitation initially starts as ice crystals or snowflakes.
It changes into different forms because of the varying temperature of the different air columns in the atmosphere.
Rain: Snowflakes leave the clouds. They meet the hotter air-column on the way from clouds to the earth’s surface. The ice crystals or snowflakes convert into water droplets and reach to the ground. This type of precipitation is called rain.
Sleet: Snowflakes leave the clouds. They meet a thick hot-air column in the atmosphere and melts. Now they enter into a cooler air column and start freezing again and reach earth like small ice crystals. This type of precipitation is called sleet.
Hail: Snowflakes leave the clouds. They meet a thin hot-air column in the atmosphere and melts for a while. Now they enter into a cooler air column again and start freezing. They grow in size as the water droplets freeze onto them. They reach the earth’s surface as big ice crystals. This type of precipitation is called hail.
Snow: Snowflakes leave the clouds and reach the earth’s surface like snowflakes. The temperature on the way down to the ground is at or below the freezing point. The low temperature does not allow snowflakes to melt. This type of precipitation is called snowfall.
The water from the earth’s surface vaporizes to the atmosphere and forms a cloud. Inside the clouds, it condenses and converts into the ice crystals or snowflakes. It then comes down to the earth’s surface as rain or snow. The water completes a full cycle which is called Water Cycle.
So, we can say that the clouds and rain are part of the process of the water cycle.
The light consists of seven colors. The mnemonic for these seven colors is ‘VIBGYOR’. It means:
These seven colors have different wavelengths. The wavelength of red color is the highest among these and that of violet color is the smallest. The colors having small wavelengths like violet, indigo and blue get scattered into space by the tiny particles present in the atmosphere. These colors look like below.
Violet Indigo Blue
As these colors get scattered into the sky that’s why the sky appears blue.
Read above the definition of fog.
The low-level condensation of the water vapors over the tiny particles present in the air is called fog. This fog appears like clouds. We can say, fog is the cloud closer to the earth’s surface.
So basically, when clouds fall on earth then they are called ‘fog’.
Humidity: Humidity is the water vapors (water in gaseous state) present in the air. The ability of air to hold water vapors increases with an increase in temperature.
Moisture: Moisture is the water (water in liquid state) present in any other solid substances like soil, wet clothes.