UPSC » UPSC CSE Study Materials » Physical Geography » Types of Clouds

Types of Clouds

This article discusses the different types of clouds and their properties. The discussion includes topics like High Clouds, Middle Clouds, Low Clouds, and other types of clouds.

Introduction

 A cloud is a huge mass that is visible to the naked eye. They are formed due to the accumulation of tiny water droplets and ice crystals that remain mixed up in the Earth’s atmosphere. Clouds belong to several types, primarily based on their shape, colour, or size. As the weather cools and the temperature falls, the water vapour and ice crystals stored inside these clouds fall on the Earth as precipitation. Precipitation can be in the form of rain, snowfall, hail, etc. This article will help you study the differences that make clouds unique and different from each other. 

Classification of clouds based on height:      

Based on the altitude or height at which the clouds are present, they can be classified into the following types:

  1. High Clouds:
    1. Cirrus Clouds.
    2. Cirrostratus Clouds.
    3. Cirrocumulus Clouds.
  2. Middle Clouds:
    1. Altostratus Clouds.
    2. Altocumulus Clouds.
  3. Low Clouds:
    1. StratoCumulus.
    2. Stratus.
    3. Nimbostratus.
  4. Great Vertical Extent Clouds:
    1. Cumulus.
    2. Cumulonimbus.

The following table summarises the characteristics of all the above mentioned four main types of clouds, High, Middle, Low, and Great Vertical Extent Clouds:

Types of Clouds

Altitude at which they are present

Characteristics

High Clouds

High clouds are found above 6000 metres or 20,000 feet from the surface of the Earth
  • High clouds are also known as Cirrus Clouds
  • High clouds are relatively thin
  • High clouds are made of ice
  • High clouds do not produce rainfall
  • High clouds indicate good weather

Middle Clouds

Middle clouds are known to form between 2000 metres to 6000 m or 6500 feet from the surface of the Earth..
  • Middle cloud is also known as Alto clouds
  • Middle clouds often produce a Virga
  • Middle clouds often indicate a near-approaching storm

Low Clouds

Low clouds occur at altitudes below 2000 metres or 6500 feet from the surface of the Earth
  • Low clouds are also called Stratus Clouds
  • Low clouds can appear cottony, bright white interspersed in the blue sky
  • Low clouds also sometimes appear dark, dense, or rainy

Great Vertical Extent Clouds

Great Vertical Extent Clouds are found to occur at very high altitudes
  • Great Vertical Extent clouds are also called Storm Clouds
  • Great Vertical Extent clouds can sometimes occur well above the level of jet flights
  • Great Vertical Extent clouds have dramatic characteristics

The names of the clouds are decided by their shape and the altitude range in which they are present. 

For high altitude clouds, the term Cirrus or Cirro is used. The term Status or Strato is used to state flat or smooth clouds. Combining ‘Cirrus’ and ‘Stratus’, we get Cirrostratus. This implies a flat or smooth cloud that is present at high altitudes. Similarly, you can crack the names of all other types of clouds by simply remembering the term used to define various clouds’ shapes and altitudes.

Classification of clouds based on their shape or appearance:

 Based on shape, clouds can be classified as follows:

  1. Cirrus clouds.
  2. Cumulus clouds.
  3. Stratus clouds.

What Are Cirrus Clouds?

  1. Cirrus Clouds are found at high altitudes, typically 6000 metres or 20,000 feet above the surface of the Earth. They are white, filament-like and thin. 
  2. They appear mostly as delicate white patches or narrow bands. 
  3. Cirrus clouds may also appear fibrous and silky like hair strands. Ice-crystals are always the main composition of Cirrus Clouds. 
  4. Depending on the density of formation of these ice-crystals, the transparency of Cirrus clouds varies. You will commonly find Cirrus clouds appearing bright yellow before sunrise and red after sunset. 
  5. Cirrus clouds are formed due to the freezing of supercooled water droplets forming ice crystals.

What Are Cumulus Clouds?

     The conventional picture that first comes to your mind when speaking of clouds is Cumulus Clouds. 

  1. Cumulus clouds are the mid-altitude clouds that look like floating pieces of fluffy cotton. 
  2. They are usually bright white. 
  3. They appear at altitudes of only 1000 metres or 3300 feet above the Earth’s Surface. 
  4. The top of the Cumulus cloud always has rounded, dome-like edges. 
  5. Cauliflower serves as the best object to understand the shape and appearance of a Cumulus cloud.
  6. All cumulus clouds are formed due to convection. As the air gets heated at the surface, it rises above and eventually cools down. After this, the moisture or water vapour undergoes condensation and forms the cloud.

What Are Stratus Clouds?

  1. The Stratus Clouds look like a huge grey or dull coloured blanket hanging low in the sky.
  2. They appear at low altitudes. 
  3. They often resemble fog and are composed of a uniform layer.
  4. When Stratus Clouds warm up, they indicate rain, and if they cool down, it means snowfall might happen.
  5. Only when the layer of Stratus cloud breaks open, the blue sky becomes visible.
  6. Stratus clouds are formed in stable conditions when calm and gentle breezes rise up and cool down on reaching over colder land or ocean surfaces.

What Are Nimbus Clouds?

  1. All the clouds that bear rain are usually termed Nimbus Clouds. 
  2. These clouds lack any features and have little characterisation.
  3. Nimbus clouds appear to cover most areas of the sky.
  4. They are often associated with moderate and continuous rain or snowfall.
  5. These clouds are present from the lower to the middle layers of the troposphere, responsible for rainfall.

Conclusion

This article covered all the important points needed to understand the different types of clouds. The major clouds such as Cirrus, Cumulus, Stratus, and Nimbus have been discussed in detail. The main characteristics of these have been covered.